Study of drug resistance and beta-lactamse production in clinical isolates of E coli and Klebsiella

7/21/2019 Study of drug resistance and beta-lactamse production in clinical isolates of E coli and Klebsiella

http://slidepdf.com/reader/full/study-of-drug-resistance-and-beta-lactamse-production-in-clinical-isolates 1/33

1

Reference ID: 2013-01436

Title of the study: Study of drug resistance and β-lactamase production in clinical isolates

of E coli and Klebsiella spp.

1. Introduction

em!ers of t"e family Enterobacteriaceae are in"a!itants of "uman intestine and are

among t"e most common "uman pat"ogens causing urinary tract infection# !lood stream

infections# pneumonias# intra-a!dominal infections# gastroenteritis# etc$ E. coli and Klebsiella

spp$ are t"e most common isolates among t"em$ %"ey are t"e source of community and "ospital-

ac&uired infections$

%"e in'udicious# empirical use of anti!iotics "as contri!uted to t"e emergence of

drug resistance$ (nti!iotic resistance is a significant pro!lem not only among nosocomial !acterial

isolates# !ut also in isolates from community-ac&uired infections# )"ere it "as traditionally !een

a!sent$

Due to t"e life-t"reatening infections caused !y E. coli and Klebsiella spp# t"eir

resistance to anti!iotics is a ma'or cause of concern$ %"ey "a*e t"e propensity to spread

genetic material t"roug" "ori+ontal gene transfer# mediated mostly !y plasmids and transposons$

%"ere may !e *arious )ays !y )"ic" E. coli and Klebsiella spp. ac&uire resistance# !ut production

of e,tended- spectrum !eta lactamase .S/ is more important$ ar!apenem drugs are currently

considered as t"e !est treatment for t"ese .S/-producing E. coli and Klebsiella spp$ /ut# t"ere

are fe) studies# )"ic" indicate emergence of resistance against car!apenems umarasamy et al

2010$



ar!apenem resistance among clinical isolates of Enterobacteriaceae, especially E

coli and K pneumoniae, is largely attri!uted to metallo-β-lactamase /$ urrently# t"e

spread of car!apenem resistant !acteria is a serious issue$ %"is emerging trend of resistance may

lead to disastrous conse&uences# as in t"e years to come# no anti!iotics may remain

effecti*e$ %"is may lead to "ig" mortality and mor!idity in patients$ Steps need to !e taen at

many le*els$ 5ne important step could !e t"e regular monitoring of t"ese organisms for drug

resistance$ (nti!iotic policy of t"e particular "ospital s"ould !e !ased on anti!iotic sensiti*ity

profile of microorganisms$ ence# )e are trying to analy+e anti!iotic sensiti*ity pattern of E.

coli and Klebsiella spp$ of !acteria at Indira 7and"i 7o*ernment edical ollege#

8agpur# India$



2. Review of literature

E coli is t"e commonest cause of urinary tract infections in !ot" community and

nosocomial settings o"anty et al 2003$

E coli )as first identified !y t"e 7erman paediatrician %"eodore .sc"eric" during

"is studies of intestinal flora of infants$ e descri!ed t"e organism in 199 as Bacterium coli

commune .sc"eric" 199 and esta!lis"ed in pat"ogenic properties in e,traintestinal infections$

%"e name Bacterium coli )as )idely used until 1;1;# )"en astellani and "almers defined t"e

genus Escherichia and esta!lis"ed t"e type species E $ coli astellani et al 1;1;$

E $ coli is gram-negati*e# rod-s"aped# non-spore forming !acteria# usually motile !y

peritric"ous flagella$ %"ey are facultati*e anaero!e and gas is usually produced from fermenta!le

car!o"ydrates$ ost strains of t"is species promptly ferment lactose or gi*e a positi*e 5-

nitrop"enyl-β-D-galactopyranoside reaction$ %"ey are met"yl red positi*e and <oges-=roauer

negati*e$ %"ey produce indole# fail to "ydrolyse urea or to gro) in oller>s 8 !rot"$ 2S

production is not detecta!le on triple sugar iron %SI agar or ligler>s iron agar I(#

p"enylalanine is not deaminated# gelatin is not li&uefied and gluconate is not o,idi+ed$ ost strains

decar!o,ylate lysine and utili+e sodium acetate# !ut t"ey do not gro) on Simmons> citrate agar

"easty et al 200$

K pneumoniae is a 7ram-negati*e# non-motile# encapsulated# lactose fermenting#

facultati*e anaero!ic# rod s"aped !acterium$ K pneumoniae is lactose fermenting# 2S and indole-

negati*e# "as a positi*e *oges-prosauer reaction# is capa!le of gro)t" in 8 and use citrate as a

sole car!on source# and is incapa!le of gro)t" at 10?$



le!siella is gram-negati*e !acteria t"at can cause different types of "ealt"care-

associated infections# including pneumonia# !loodstream infections# )ound or surgical site

infections# and meningitis @iipedia$

le!siella !acteria "a*e de*eloped antimicro!ial resistance# most recently to t"e

class of anti!iotics no)n as car!apenems$ le!siella !acteria are normally found in t"e "uman

intestines )"ere t"ey do not cause disease$ %"ey are also found in "uman stool feces$ In

"ealt"care settings# le!siella infections commonly occur among sic patients )"o are recei*ing

treatment for ot"er conditions$ =atients )"ose care re&uires de*ices lie *entilators !reat"ing

mac"ines or intra*enous *ein cat"eters# and patients )"o are taing long courses of certain

anti!iotics are most at ris for le!siella infections$ ealt"y people usually do not get le!siella

infections$

Antibiotic Resistance

%"e in'udicious# empirical use of anti!iotics "as contri!uted to t"e emergence of

resistant !acteria$ (nti!iotic resistance is a significant pro!lem not only among nosocomial

!acterial isolates# )"ere it "as traditionally !een recogni+ed# !ut also in (# )"ere it "as

traditionally !een a!sent$

%"e lieli"ood of multi-drug resistance is muc" greater in patients )it" nosocomial

infections$ In recent years# !acterial resistance to different anti!iotics "as risen dramatically lea*ing

p"ysicians )it" fe) t"erapeutic options$ .,tended spectrum β- lactamases .S/ producing

organisms "a*e !ecome common "ospital pro!lems$ Since t"ese rates of resistance to anti!iotics

differ from region to region# in maing an appropriate c"oice of empiric or definiti*e t"erapy# it is

useful to a*ail of t"e information on pre*ailing le*els of antimicro!ial resistance among common

pat"ogens$



β -lactamase production is t"e most common mec"anism of β-lactam drug resistance

in gram-negati*e !acteria /lac 200$ .ntero!acteriaceae producing !ot" .S/s and (mp β-

lactamases "a*e !een increasingly reported )orld)ide$ Since (mp producing organisms can act

as "idden reser*oirs for .S/s# it is important for clinical micro!iology la!oratories to !e a!le to

detect .S/ production in t"ese organisms on a routine !asis$ Antil recently# car!apenems )ere

t"e c"oice for t"e t"erapeutic management of multidrug-resistant gram-negati*e !acterial

infections$ urrently# t"e spread of car!apenem-resistant !acteria "as caused gra*e concern due to

t"e limited c"oice in anti!iotics for treating infections caused !y t"em$ %"e resistance to

car!apenems due to /s in entero!acteriaceae is increasingly recogni+ed$ Bor t"is reason#

aggressi*e sur*eillance of / producers )ere e,tremely important$

<arious mec"anisms of drug resistance in gram-negati*e !acilli include .S/#

(mp β-lactamase production# efflu, mec"anisms and porin deficiency$ β lactamases continue to

!e t"e leading cause of resistance to β-lactam anti!iotics in gram negati*e !acteria$ (mongst t"e

mec"anisms of resistance to t"ird generation cep"alosporins# production of .S/s and (mp β-

lactamases are t"e most common$ Since !ot" .S/ and (mp β-lactamases are encoded on

plasmids and confer a selecti*e ad*antage to strains "ar!ouring t"ese in a "ospital setting$ It is

important to no) t"e occurrence of .S/ and (mp producing strains as )ell as t"eir anti!iotic

suscepti!ilities to ne)er agents to guide empirical t"erapy for *arious infections %ane'a et al

2009$

.S/ are t"e en+ymes t"at "ydrolyse and cause resistance to o,ymino-

cep"alosporins and a+treonam$ =roduction of t"ese en+ymes is eit"er c"romosomally mediated or

plasmid mediated$ =oint amino acid su!stitution of t"e classical plasmid mediated β-lactamases

lie %.-1# %.-2 and S<-1 increases t"e spectrum of acti*ity from earlier generation β-

lactams to 3rd

generation cep"alosporins and mono!actams$ o)e*er# t"ey retain t"eir sta!ility

against cep"amycins and car!apenems and are in"i!ited to an e,tent !y β-lactamase in"i!itors suc"



as cla*ulanic acid$ /eing plasmid mediated t"ese en+ymes spread fast amongst *arious !acteria and

are important !y infection control# clinical and t"erapeutic implication Rodrigues et al 2004$

(s per SI 2012 guidelines# )"en using t"e ne) interpreti*e criteria# routine

.S/ testing is no longer necessary !efore reporting results i$e$# it is no longer necessary to edit

results for cep"alosporins# a+treonam# or penicillins to resistant$ o)e*er# .S/ testing may still

!e useful for epidemiological or infection control purposes anual 2011$ .S/ production can

!e detected !y dou!le dis synergy test DDS% using amo,icla* and cefota,ime (-%C

=itout et al 2003# S"o!"a et al 200# S"o!"a et al 200; and piperacillin-ta+o!actum and cefepime

=I%-= =itout et al 2003# S"o!"a et al 200# S"o!"a et al 200;# Rodrigues et al 2004$ %"e

in"i!itor-!ased confirmatory test approac" is most promising for isolates t"at do not coproduce an

in"i!itor-resistant β-lactamase lie (mp "an et al 200;$ Since "ig"-le*el e,pression of (mp

β-lactamases may mas recognition of .S/s# t"erefore t"e uni&ue com!ination of cefepime and

piperacillin-ta+o!actam can !e used to detect .S/s anual 2011$ ig"-le*el e,pression of

(mp production "as minimal effect on acti*ity of cefepimeE maing t"is drug is more relia!le for

.S/ detection in presence of (mp Rodrigues et al 2004$

(mp β-lactamases are clinically important !ecause t"ey confer resistance to

narro)-# e,panded-# and !road-spectrum cep"alosporins# β-lactam-β-lactamase in"i!itor

com!inations and a+treonam$ %"e c"romosomally mediated β-lactamase production is mainly

t"roug" e,pression of (mp gene )"ic" is eit"er constituti*e or induci!le$ =lasmid-encoded

(mp "a*e !een found around t"e )orld in nosocomial and non-nosocomial isolates and "a*e

!een lined to treatment failure Ruppe et al 2006# Faco!y 200;$ In most genera of t"e family

entero!acteriaceae# (mp is induci!le ="ilippon et al 2002$ Anlie c"romosome-mediated

(mp# plasmid-encoded (mp en+ymes are almost al)ays e,pressed constituti*ely /us" et al

1;;$ =lasmid mediated induci!le β-lactamases are e,tremely rare$



.n+yme e,traction met"ods "a*e traditionally !een cited as t"e optimum p"enotypic

detection met"od for (mp acti*ity$ o)e*er# t"ese are la!our-intensi*e and not suita!le for

routine clinical use %an et al 200;$ %"erefore# dis !ased met"ods are preferred$ efo,itin and

imipenem are strong inducers of (mp β-lactamases !ut are muc" more sta!le for "ydrolysis$

@"ereas cefota,ime# ceftria,one# cefta+idime# cefepime# cefuro,ime# piperacillin# and a+treonam

are )ea inducers and )ea su!strates !ut can !e "ydrolysed if enoug" en+yme is made Faco!y

200;$ Burt"er# (mp β-lactamases are poorly in"i!ited !y cla*ulanic acidE "o)e*er# t"ey are

in"i!ited !y clo,acillin$ 5t"er in"i!itors of t"e (mp en+yme are also )ell descri!ed and )"ic"

include !oronic acid compounds and no*el in"i!itors suc" as Syn21;0 %an et al 200;$ lo,acillin

!ased met"ods suc" as clo,acillin com!ined dis diffusion %an et al 200; and dou!le dis

synergy test Ruppe et al 2006 can detect !ot" induci!le and non-induci!le (mp β-lactamase$

ar!apenemases are classified into class (# / and D$ lass / car!apenemases

consist of / only$ (s per SI 2012 guidelines# institutional infection control procedures or

epidemiological in*estigations may re&uire identification of car!apenemase-producing

entero!acteriaceae$ ar!apenemase-producing isolates usually test intermediate or resistant to one

or more car!apenems using t"e current interpreti*e criteria and test resistant to one or more agents

in cep"alosporin su!class III e$g$# cefopera+one# cefota,ime# cefta+idime# cefti+o,ime# and

ceftria,one$ %"erefore# testing could !e limited to isolates )it" t"ese c"aracteristics$ SI 2012

guidelines recommended modified odge test for car!apenemase production amongst

entero!acteriaceae isolates$ Burt"er t"ey added t"at for isolates )it" positi*e modified odge test#

minimum in"i!itory concentration I test s"ould !e performed !efore reporting any

car!apenem results# since car!apenem I interpretations are solely !ased on t"e I and s"ould

not !e c"anged regardless of t"e % result$ (lt"oug" SI 2012 "as not recommended % for

gram negati*e non-fermentati*e !acilli 8oyal et all 200; used it for t"e car!apenemase detection

in gram-negati*e non-fermentati*e !acilli$



Since / can "ydrolyse a *ery )ide range of !road-spectrum β-lactams# /-

producing gram-negati*e !acteria usually demonstrate consistent resistance to a *ariety of !road-

spectrum β-lactams# including o,yiminocep"alosporins# cep"amycins and car!apenems )"ic" are

t"e last resort for t"e control of infections caused !y gram negati*e !acteria$ %"us# /-producing

gram-negati*e !acteria "a*e !een recogni+ed to !e among t"e most important nosocomial

pat"ogens$ @it" t"e )orld)ide increase in t"e occurrence# types and rate of dissemination of /#

early detection is critical$ %"e !enefits of suc" include timely implementation of strict infection

control practices as )ell as clinical guidance regarding t"e potential riss for t"erapeutic failure$

/s are in"i!ited !y c"elating agents suc" as .D%($ (ddition of +inc "as !een no)n to increase

t"e acti*ity of metallo !eta lactamases$ %"erefore# met"ods using t"ese su!stances can !e used to

detect / production$



10

3. Aims and Objectives

1$ %o study t"e antimicro!ial suscepti!ility in clinical isolates of E. coli and Klebsiella spp$

2$ %o study t"e β-lactamase production in t"e clinical isolates of E. coli and Klebsiella spp$



. !aterials and !ethods

%"e study )as conducted at Department of icro!iology# Indira 7and"i

7o*ernment edical ollege# and 8agpur from 1st ay 2013- 30t"

Fune 2013$<arious samples lie

pus# urine# SB# sputum# !lood etc$ )ere collected and processed !y standard micro!iological

tec"ni&ues$ (ll t"e samples )ere cultured on !lood and coney media$ %"e isolates of E. coli

and Klebsiella spp$ )ere identified !y colony c"aracteristics# morp"ology and !ioc"emical

reactions /allo)s et al 1;;1$

Identification of E. coli ric"ton 200

E. coli is a gram negati*e# straig"t# s"ort# slender# sluggis"ly motile !acillus$ (fter

19G24 "ours of incu!ation at 3o# E. coli forms colonies as follo)s:

1$ /lood agar - large 2-3 mm# circular# lo) con*e, and non-pigmented$

2$ coney medium: arge# lactose fermenting# moist$

3$ /ioc"emical reactions: atalase positi*eE o,idase negati*eE lactose# glucose and mannitol

fermented )it" production of acid and gasE sucrose not fermentedE indole positi*eE met"yl red

positi*eE citrate negati*eE urease negati*eE 2S not produced$

Identification of le!siella spp$

le!siella is s"orter and t"icer gram negati*e# non-motile# capsulated !acilli$

%"e colony c"aracteristics are:

1$ /lood agar - lu,uriant# greyis"-)"ite# con*e, and mucoid

2$ coney medium G lactose fermenting# mucoid$

3$ /ioc"emical reactions: atalase positi*eE o,idase negati*eE lactose# glucose# mannitol and

sucrose fermented )it" production of acid and gasE indole negati*eE citrate positi*eE urease



10

positi*eE 2S not produced$

(nti!iotic sensiti*ity test -

(ntimicro!ial suscepti!ility testing )as performed !y ir!y /auer met"od

/auer et al 1;66 as per t"e SI guidelines 2012$

edium used )as uller inton agar ($ %"e inoculum tur!idity )as

ad'usted to 0$ cBarland standard$ ommercially a*aila!le diss i media p*t ltd$ of 6 mm

diameter )it" recommended potency )ere used$ ( plates )ere inoculated !y streaing e*enly

t"e s)a! t"ree times$ %"e diameters of t"e +one of in"i!ition including anti!iotic dis

)ere measured$ Interpretation i$e$ suscepti!le# intermediate and resistant )as done$

et"ods of !eta-lactamases detection anual 2011

1$ .S/ detection

i$ Initial screening and p"enotypic confirmatory test SI 2012: ( la)n culture of 0$

cBarland inoculum of t"e test strain )as e,posed to a dis of cefta+idime$ (fter incu!ation at

3o

for 16-19 "ours# t"e +one diameter H 22 mm indicates .S/ production$ %"e la)n culture

of t"e test strain )as done on ($ Diss of cefta+idime 30 g and cefta+idime-cla*ulanic

acid 30J10 g )ere placed on it$ (fter incu!ation at 3o for 16-19 "our# a K -mm increase in

a +one diameter for cefta+idime-cla*ulanic acid *ersus its +one )"en tested alone indicates

.S/ production$

ii$ Dou!le dis synergy test DDS% using amo,ycla* and cefota,ime and piperacillin-

ta+o!actum and cefepime: ( plates )ere s)a!!ed to form a la)n culture )it" 0$ cBarland

standard inoculum of t"e test strain$ 5n t"e ( plate# a dis of cefota,ime 30 g )as

placed 20 mm apart# centre-to-centre# from amo,icla* 20J10 g dis )"ereas piperacillin-



ta+o!actam 100J10 g dis )as placed 2 mm apart# centre-to-centre from cefepime 30 g

dis$ =lates )ere incu!ated at 3o

o*ernig"t and )ere e,amined for en"ancement of +one

in"i!ition of cefota,ime and cefepime at t"e side facing amo,icla* and piperacillin-ta+o!actam

dis respecti*ely$ 5rganisms t"at )ill s"o) a clear e,tension of in"i!ition +one to)ards t"e dis

of amo,icla* and piperacillin-ta+o!actam )ere considered .S/ positi*e$

2$ (mp L-lactamase detection

i$ Screening test: ( la)n culture of 0$ cBarland inoculum of t"e test strain )as e,posed

to a dis of cefo,itin 30 g$ (fter o*ernig"t incu!ation at 3o# t"e +one diameter H19 mm

)as suspected as (mp producer$

ii$ efo,itin-cefota,ime dis antagonism test: ( la)n culture of 0$ cBarland inoculum of t"e

test strain )as e,posed to a dis of cefota,ime 30 g and cefo,itin 30 g placed at a distance

of 1$ cm from edge to edge$ (fter o*ernig"t incu!ation# t"ere )as flattening of radius of

+one of in"i!ition produced !y cefota,ime on t"e side nearest t"e cefo,itin dis in case of (mp

β-lactamase producer organisms$

iii$ efta+idime-imipenem antagonism test: ( plate )as inoculated )it" 0$

cBarland inoculum of t"e test organism$ efta+idime 30 g and imipenem 10 g diss )ere

placed 20 mm apart from centre to centre$ %"e plate )ere incu!ated o*ernig"t at 3o$ Isolates

s"o)ing !lunting of cefta+idime +one of in"i!ition ad'acent to imipenem dis )ere confirmed

positi*e for induci!le (mp production$



3$ / detection

It )as tested !y performing initial screening test follo)ed !y com!ined dis test$

i$ Screening test: in t"e test# la)n culture of 0$ cBarland inoculum of t"e test strain )as

e,posed to a disc of meropenem 10 g$ (fter o*ernig"t incu!ation# t"e +one diameter around 16-

21mm indicated car!apenemase / production$

ii$ om!ined dis test: - In t"is test# t"e la)n culture of 0$ cBarland inoculum of t"e test strain

)as e,posed to a dis of imipenem 10 g and imipenem-.D%( 10J0 g$ %"e difference of

K mm in +ones of in"i!itions of t)o diss )ill indicate / production$



1

". Observations and Results

%"e study )as conducted in Department of icro!iology# Indira 7and"i

7o*ernment edical ollege# 8agpur during 1st

ay 2013 to 30t"

Fune 2013$

( total of 60 strains of le!siella and 40 strains of E coli isolated from

samples collected from different infections )ere included in t"e study$ (ll t"e 60 strains of

le!siella )ere K pneumoniae.

%a!le 1 s"o)s *arious infections from )"ic" K pneumoniae and E coli

strains )ere isolated$

Table 1. #ifferent infections caused by K pneumoniae and E coli

Infection $o. of K pneumoniae isolates %&' No. of E coli isolates %&'

o)er respiratory tract

infection R%I

20 33$3 3 $

Arinary tract infection A%I 1 2$0 2 62$

/acteremia 1 2$0 9 20$0

@ound Infection 10 16$ 4 10$0

%otal 60 100 40 100

%a!le 1 s"o)s t"at K pneumoniae and E coli )ere causati*e agents of lo)er

respiratory tract infection# urinary tract infection# !acteremia and )ound infection$ Burt"er K

pneumoniae )as more common in %RI as compared to E coli and E coli )as more common in

A%I$

%a!le 2 s"o)s age and se, distri!ution of cases of K pneumoniae and E coli

infections$



%a!le 2 s"o)s t"at K pneumoniae infections )ere more common in M60 40N

follo)ed !y 21-30 20N and 0-10 16$6N age groups. E coli infections )ere more common in

21-30 3$N follo)ed !y 31-40 2N age groups$ K pneumoniae infections )ere more

common in males and E coli infections )ere more common in females$

Table 2. A(e and se) distribution of cases in K pneumoniae and E coli infections

A(e %years'

K pneumoniae infection E coli infection

!ale %&' *emale %&' Total !ale %&' *emale %&' Total

0-10 6 19$9 4 14$3 10 16$ 2 12$ 1 4$2 3 $

11-20 2 6$3 1 3$6 3 $0 1 6$3 1 4$2 2 $0

21-30 4 12$ 9 29$6 12 20$0 3 19$9 12 0 1 3$

31-40 2 6$3 2 $1 4 6$ 4 2 6 2 10 2$0

41-0 2 6$3 1 3$6 3 $0 1 6$3 1 4$2 2 $0

1-60 2 6$3 2 $1 4 6$ 1 6$3 1 4$2 2 $0

M60 14 23$3 10 3$ 2440 4 2 2 9$3 6 1

%otal 32 29 60 16 24 40

%a!le 3 s"o)s (ntimicro!ial resistance amongst . coli and pneumonia

isolates$ K pneumoniae isolates )ere completely resistant to aminopenicillin 100N$ o)e*er#

t"ey s"o)ed *aria!le resistance to cep"alosporins 11$6N - 30N# tetracycline 60$0N# norflo,acin

0$0N# cotrima,a+ole 46$6N$ E coli s"o)ed 20N resistance to aminopenicillin and 2N

resistance to 1st

and 2nd

generation cep"alosporins$ (ll K pneumoniae and E coli isolates )ere



Table 3. Antimicrobial resistance amon(st + coli and , -neumonia isolates

#ru(s

E coli

n / %&'

K pneumoniae

n 0/ %&'

8itrofurantoinO 0 0

8orflo,acinO 16 40$0 30 0$0

otrimo,a+oleO 14 3$0 29 46$6

ar!enicillinO 4 10$0 6 10$0

(mpicillin 9 20$0 60 100

(mo,ycla* 9 20$0 42 0$0

ep"alot"in 10 2$0 19 30$0

efuro,ime 10 2$0 19 30$0

efo,itin 2 $0 2 3$3

ep"ota,ime 2 $0 11$6

efipime 2 $0 11$6

=iperacillin 4 10$0 11$6

=iperacillin %a+o!actum 0 0

Imipenem 0 0

7entamycin 4 10$0 6 10$0

(miacin 0 0

%o!eramycin 4 10$0 6 10$0

8etillin 1 2$ 4 6$6

%etracycline 20 0$0 36 60$0

10



17

O- Arinary anti!iotics t"oug" useful in A%I only# t"e isolates from all t"e infections )ere

tested for suscepti!ility to t"em$

suscepti!le to piperacillin ta+o!actum# imipenem and amiacin$ (mong aminoglycosides# amiacin

s"o)ed !est suscepti!ility in our study$

A4TA!A5+ 6RO#74TIO$

In present study# .S/ production amongst entero!acteriaceae isolates s"o)ing positi*e screening

)as tested !y

1$ ="enotypic confirmatory test

2$ Dou!le dis synergy test

%a!le 4 s"o)s t"e comparison of different met"ods of .S/ production amongst

entero!acteriaceae isolates s"o)ing positi*e screening test$

Table . 4om-arison of different methods of +58 -roduction testin( amon(st

enterobacteriaceae isolates %n 1//'

!ethod

6henoty-ic confirmatory

%4A9 4A4'

#ouble dis; syner(y

A!4 4T< 6IT 46!

8o$ of strains

s"o)ing .S/

production N

6 6$0 4 4$0 $0

(P G efta+idime# ( - efta+idime cla*ulanic acid# ( G (mo,ycla*# %C G efota,ime#

=I% G =iperacillin-ta+o!actam# efepime - =



%a!le 4 s"o)s t"at amongst 100 entero!acteriaceae isolates# .S/ production )as

ma,imally 6$0N detected !y p"enotypic confirmatory met"od (P-($ Dou!le dis synergy

test )as a!le to detect .S/ production in 4$0N isolates !y using (-%C and in $0N isolates

!y using =I%-=$ (ll isolates detected as .S/ positi*e !y dou!le dis synergy test !y using

eit"er of t"e met"ods "a*e s"o)n .S/ production !y p"enotypic confirmatory met"od also$

In present study# (mp production )as tested amongst entero!acteriaceae isolates

s"o)ing positi*e screening$ It )as tested !y-

Q efo,itin-cefota,ime dis antagonism test

Q efta+idime-imipenem antagonism test

%a!le s"o)s t"e comparison of tests of (mp production amongst

entero!acteriaceae isolates$

Table ". 4om-arison of different tests for Am-4 -roduction amon(st enterobacteriaceae

isolates %n 1//'

Tests for Am-4 -roduction

4efo)itincefota)ime dis;

anta(onism

4efta=idimeimi-enem

anta(onism

8o$ of strains s"o)ing

(mp production N 2 2$0 2 2$0

%a!le s"o)s t"at amongst 100 entero!acteriaceae isolates# (mp production )as

e&ually detected !y !ot" cefta+idime-imipenem dis antagonism test and cefo,itin-cefota,ime dis

antagonism test 2$0N$ %"e isolates detected positi*e for (mp production !y cefo,itin-



cefota,ime dis antagonism "ad s"o)n (mp production !y cefta+idime-imipenem dis

antagonism test too$

%a!le 6 s"o)s β-lactamase production amongst entero!acteriaceae isolates in

present study$

Table 0. lactamase -roduction amon(st enterobacteriaceae isolates %n 1//'

+nterobacteriaciae isolates +58 %&' Am-4 %&' !8 %&' Total

E coli n40 2$0 0 0 2$0

K pneumoniae n60 46$6 23$3 0 610

%otal n100 66 22 0 99

%a!le 6 s"o)s t"at .S/ production )as more 6$6N in pneumoniae as

compared to E coli N$ (mp production )as seen in K pneumoniae only 3$3N and not in .

coli$ 8one of t"e strains )ere positi*e for /$ %"us# total / lactamase production )as 9N in .

coli and K pneumoniae isolates in our study$



0. #iscussion

%"e study )as conducted in Department of icro!iology# Indira 7and"i

7o*ernment edical ollege# and 8agpur during 1st

ay 2013 to 30t"

Fune 2013$

( total of 60 strains of le!siella and 40 strains of E coli isolated from samples

collected from different infections )ere included in t"e study$ (ll t"e 60 strains of le!siella )ere

K pneumoniae.

It )as found out t"at K pneumoniae )as more common in lo)er respiratory tract

infections 33$3N$ K pneumoniae is a primary pat"ogen capa!le of causing pneumonia in ot"er

)ise# "ealt"y people$ o)e*er most infections are ac&uired in t"e "ospital and occur in t"ose )"o

are de!ilitated !y *arious underlying conditions Far*is et al 1;9$

E coli )as more common in urinary tract infections 62$N as compared to K

pneumoniae$ E coli is t"e leading cause of !ot" community ac&uired and nosocomial urinary tract

infections Donnen!erg 200$ 5t"er infections caused !y K pneumoniae and E coli include

!acteremia and )ound infection %a!le 1$

@"en compared )it" t"e age aspect# it )as found out t"at K pneumoniae infections

)ere more common in e,tremes of ages 16$6N and 40N in )"ic" ris of infection is "ig"er$

.lderly patients are more prone to infections due to age-related decrease in immunity and also due

to rapidly fatal underlying illness 7uillermo et al 2013$

E coli infections )ere found to !e more common in 21-30 and 31-40 age groups

3$N and 2N resp$$ %"e infections )ere again found to !e more common in females$ %"e

infections in t"is age group )ere mostly urinary tract infection$ @omen are more suscepti!le to

urinary tract infections t"an men# and t"eir infections tend to recur$ 5ne reason is t"at t"e uret"ra

t"e tu!e t"at carries urine a)ay from t"e !ladder is s"orter in )omen t"an in men$ Bre&uent



se,ual intercourse also increases a )oman>s ris of de*eloping A%Is$ ontracepti*e spermicides

and diap"ragm use are ot"er ris factors Arinary %ract Infections# @e!$

It )as o!ser*ed t"at %a!le 3 resistance to routinely prescri!ed urinary anti!iotic

suc" as norflo,acin# cotrimo,a+ole and car!enicillin "as !een introduced in commonest etiological

agents of A%I i$e E coli and K pneumoniae. %"e unfre&uently used urinary anti!iotic nitrofurantoin

is spared from t"e de*elopment of t"e resistance in t"e isolates in our study$ K pneumoniae s"o)ed

complete resistance to aminopenicillin and E coli s"o)ed only 20N resistance to t"e drug$ %"e

resistance to different cep"alosporins in !ot" genera *aried from N to 30N %a!le 3$ %"e

resistance to cefamycin )as 3$3N and N in E coli and K pneumoniae respecti*ely$ Isolates of

neit"er of t"e genera s"o)ed resistance against piperacillin and ta+o!actum# imipenem$ (mongst

aminoglycosides amiacin s"o)ed complete sensiti*ity$ %"e resistance to ot"er aminoglycosides

*aried from 2$N to 10N$ 5*erall K pneumoniae isolates s"o)ed more resistance as compared to E

coli$

β-lactamase production is t"e most common mec"anism of β-lactum drug resistance

in gram-negati*e !acteria /lac et al 200$ (mongst different β-lactamases# / production

)as not o!ser*ed in our study$ Since (mp-producing organisms can act as "idden reser*oirs for

.S/s# it is important for clinical micro!iology la!oratories to !e a!le to detect .S/ production

in t"ese organisms on a routine !asis =itout et al 2003$ Antil recently# car!apenems )ere t"e

c"oice for t"e t"erapeutic management of multidrug-resistant gram-negati*e !acterial infections$

urrently# t"e spread of car!apenem-resistant !acteria "as caused gra*e concern due to t"e limited

c"oice in anti!iotics for treating infections caused !y t"em @als" 2010$ %"e resistance to

car!apenems due to metallo-β-lactamases /s in entero!acteriaceae is increasingly recogni+ed

%ato et al 2010$ Bor t"is reason# aggressi*e sur*eillance of / producers )ere e,tremely

important S"i!ata et al 2003$



22

In present study# .S/ production )as detected amongst entero!acteriaceae isolates

%a!le 4 !y using different met"ods$ (mongst 100 entero!acteriaceae isolates# .S/ production

)as ma,imally 6$0N detected !y p"enotypic confirmatory met"od (P-($ @"ereas dou!le

dis synergy test )as a!le to detect .S/ production in 4$0N isolates !y using (-%C and in

$0N isolates !y using =I%-=$ (ll isolates detected as .S/ positi*e !y dou!le dis synergy

test !y using eit"er of t"e met"ods "a*e s"o)n .S/ production !y p"enotypic confirmatory

met"od also$ (s compared to dou!le dis synergy test !y any met"od# p"enotypic confirmatory

met"od suggested !y SI guidelines for .S/ production detected .S/ production in more

num!er of t"e isolates "an et al 2009 reported t"at amongst t"e ;0 isolates tested# dou!le dis

synergy test detected .S/s in 40 isolates# )"ereas# p"enotypic confirmatory test detected .S/s

in 3; isolates$

(s per SI 2012 guidelines# )"en using t"e current interpreti*e criteria# routine

.S/ testing is no longer necessary !efore reporting results i$e$# it is no longer necessary to edit

results for cep"alosporins# a+treonam# or penicillins to resistant$ o)e*er# .S/ testing may still

!e useful for epidemiological or infection control purposes SI 2012$ In t"e present study# )e

"a*e follo)ed SI 2012 guidelines for .S/ testing !y using initial screening and p"enotypic

confirmatory test !ut additionally )e "a*e performed dou!le dis synergy test DDS% using

amo,icla* and cefota,ime (-%C and piperacillin-ta+o!actum and cefepime =I%-=$

%"e in"i!itor-!ased confirmatory test approac" is most promising for isolates t"at do not coproduce

an in"i!itor-resistant β-lactamase lie (mp$ Since "ig" le*el e,pression of (mp β-lactamases

may mas recognition of .S/s# t"erefore in present study# t"e uni&ue com!ination of cefepime

and piperacillin-ta+o!actam )as used to detect .S/s$ ig" le*el e,pression of (mp production

"as minimal effect on acti*ity of cefepimeE maing t"is drug more relia!le for .S/ detection in

presence of (mp$ %a+o!actam and sul!actam are muc" less liely to induce (mp β-lactamases



23

and are# t"erefore# prefera!le in"i!itors for .S/ detection "an et al 2009$ In t"e present study#

t"e coproduction of .S/ and (mp )as not detected$ ence# superiority of t"is test )as not

completely re*ealed$ Some aut"ors ad*ocate inclusion of cefepime in differentiation of .S/

*ersus (mp$ o)e*er# it is important to remem!er t"at cefepime "as lo) I to .S/s#

!ecause it is a +)itterion and enters t"e periplasmic space efficiently$ ig" inoculum testing

generally unco*ers t"e intrinsic acti*ity of .S/ against cefepime$ linical la!oratories are still

not fully a)are of t"e importance of .S/ and (mp$ %"ey need to de*elop &uic screening

met"ods to assess t"e mec"anism of β-lactam resistance in t"e isolates so t"at appropriate

medication can !e gi*en Rodrigues et al 2004$

In present study# (mp production )as tested amongst entero!acteriaceae isolates

!y using different tests %a!le $ (mongst 100 entero!acteriaceae isolates# (mp production )as

e&ually 2$0N detected !y cefta+idime-imipenem dis antagonism test and cefo,itin-cefota,ime

dis antagonism test$ %"e isolates detected positi*e for (mp production !y cefo,itin-cefota,ime

dis antagonism "ad s"o)n (mp production !y cefta+idime-imipenem dis antagonism test too$

SI 2012 guidelines "a*e not mentioned any criteria for (mp detection$ In

present study# )e "ad performed different tests to detect (mp production amongst

entero!acteriaceae isolates$ (mp β-lactamases are clinically important !ecause t"ey confer

resistance to narro)-# e,panded-# and !road-spectrum cep"alosporins# β-lactam-β-lactamase

in"i!itor com!inations and a+treonam$ linical micro!iology la!oratories s"ould !e a!le to detect

!acterial strains producing (mp en+ymes# since t"ese strains may appear suscepti!le to a

particular β-lactam anti!iotic in *itro# !ut s"o) no clinical response )"en used to treat serious

infections antarelli et al 200$ %"e c"romosomally mediated β-lactamase production is mainly

t"roug" e,pression of (mp gene t"at is eit"er constituti*e non-induci!le or induci!le$ .n+yme

e,traction met"ods "a*e traditionally !een cited as t"e optimum p"enotypic detection met"od for



(mp acti*ity$ o)e*er# t"ese are la!our-intensi*e and not suita!le for routine clinical use$

%"erefore# in present study# )e "a*e used dis-!ased met"ods to detect t"e production of (mp β-

lactamases$ (mp β-lactamases production )as detected !y using t"e diss of cefo,itin-

cefota,ime and cefta+idime-imipenem$ efo,itin and imipenem are strong inducers of (mp β-

lactamases !ut are muc" more sta!le for "ydrolysis$ @"ereas cefota,ime# ceftria,one# cefta+idime#

cefepime# cefuro,ime# piperacillin and a+treonam are )ea inducers and )ea su!strates !ut can

!e "ydrolysed if enoug" en+yme is made Faco!y 200;$

In present study# .S/ and (mp production )as tested amongst E coli and K

pneumoniae isolates$ (ll t"e strains )ere screening test negati*e for / "ence none are /

producer$ o-production of .S/ and (mp )as not o!ser*ed$ In present study# .S/ production

)as seen in N of E coli strains and 6$6N of K pneumoniae isolates maing 6N in

entero!acteriaceae strains studied %a!le 6$ (mp production )as seen in 2N of K pneumoniae

isolates and not seen in E coli isolates$ %"us in total 9N of t"e E coli and K pneumoniae isolates

s"o)ed !eta-lactamase production$ %ane'a et al 2009 reported 36$N .S/ production )it" t"e

"ig"est .S/ positi*ity in le!siella 1$2N follo)ed !y t"at in E. coli 40$2N$ 7upta et al

2012 in t"eir study on nosocomial isolates of K. pneumoniae reported 32N (mp production$



>. 4onclusion

Q K pneumoniae )as more common in lo)er respiratory tract infections 33$3N and E coli )as

more common in urinary tract infections 62$N$

Q K pneumoniae infections )ere more common in e,tremes of ages in )"ic" ris of infection is

"ig"er$

Q E coli infections )ere found to !e more common in 21-30 and 31-40 age groups 3$N and

2N resp$$ %"e infections )ere again found to !e more common in females$

Q Resistance to routinely prescri!ed urinary anti!iotic suc" as norflo,acin# cotrimo,a+ole and

car!enicillin "as !een introduced in commonest etiological agents of A%I i$e E coli and K

pneumoniae. %"e unfre&uently used urinary anti!iotic nitrofurantoin is spared from t"e

de*elopment of t"e resistance in t"e isolates$

Q K pneumoniae s"o)ed complete resistance to aminopenicillin and E coli s"o)ed only 20N

resistance to t"e drug$

Q %"e resistance to different cep"alosporins in !ot" genera *aried from N to 30N$ %"e

resistance to cefamycin )as 3$3N and N in E coli and K pneumoniae respecti*ely$

Q Isolates of neit"er of t"e genera s"o)ed resistance against piperacillin and ta+o!actum#

imipenem$

Q (mongst aminoglycosides amiacin s"o)ed complete sensiti*ity$ %"e resistance to ot"er

aminoglycosides *aried from 2$N to 10N$

Q 5*erall drug resistance )as more common in K pneumoniae isolates as compared to E coli$

Q (mongst different β-lactamases# / production )as not o!ser*ed in our study$



Q .S/ production )as ma,imally 6$0N detected !y p"enotypic confirmatory met"od (P-

($ @"ereas dou!le dis synergy test )as a!le to detect .S/ production in 4$0N isolates

!y using (-%C and in $0N isolates !y using =I%-=$

Q (mp production )as e&ually 2$0N detected !y cefta+idime-imipenem dis antagonism test

and cefo,itin-cefota,ime dis antagonism test$

Q o-production of .S/ and (mp )as not o!ser*ed$

Q .S/ production )as seen in N of E coli strains and 6$6N of K pneumoniae isolates maing

6N in entero!acteriaceae strains studied$ (mp production )as seen in 2N of K pneumoniae

isolates and not seen in E coli isolates$ %"us in total 9N of t"e E coli and K pneumoniae

isolates s"o)ed !eta-lactamase production$

Q Introduction of / or car!apenemase production in entero!acteriaceae is a matter of great

concern$ ucily t"e strains in our setup are spared till date$ %"e )idespread use of

antimicro!ials in community eit"er due to self-medication or incorrect prescription is t"e

possi!le factor fuelling t"e emergence of resistant strains$ %"erefore# careful monitoring of drug

resistance and β-lactamase especially car!apenemase is necessary$ It is a "ig" time for

micro!iology la!oratories to introduce β-lactamase testing routinely for t"e no)ledge of t"eir

pre*alence and for t"e measures to !e taen to control t"eir spread$ %imely no)ledge of

aetiology and antimicro!ial resistance pattern of !acterial isolates can "elp in rational use of

anti!iotics and control of drug resistance$



?. 5ummary

%"e study )as conducted at Department of icro!iology# Indira 7and"i

7o*ernment edical ollege# and 8agpur from 1st ay 2013- 30t"

Fune 2013$

%"e aims and o!'ecti*es )ere to study t"e antimicro!ial suscepti!ility and t"e β-

lactamase production in t"e clinical isolates of E. coli and Klebsiella spp$

( total of 60 strains of le!siella and 40 strains of E coli isolated from samples

collected from different infections )ere included in t"e study$ (ll t"e 60 strains of le!siella )ere

K pneumoniae. %"e isolates )ere su!'ected to anti!iotic suscepti!ility test !y ir!y /auer met"od

as per t"e SI guidelines$ Different !eta-lactamase production i$e .S/# (mp# / )as

studied$ .,tended spectrum β-lactamase production amongst entero!acteriaceae isolates s"o)ing

positi*e screening )as tested !y p"enotypic confirmatory test and dou!le dis synergy test using

cefota,ime-amo,icla* and piperacillin-ta+o!actam - cefepime diss$ # (mp production )as tested

amongst entero!acteriaceae isolates s"o)ing positi*e screening$ It )as tested !y cefo,itin-

cefota,ime dis antagonism test and cefta+idime-imipenem antagonism test$

K pneumoniae and E coli )ere causati*e agents of lo)er respiratory tract infection#

urinary tract infection# !acteremia and )ound infection$ Burt"er K pneumoniae )as more

common in %RI as compared to E coli and E coli )as more common in A%I$

K pneumoniae infections )ere more common in M60 40N follo)ed !y 21-30 20N and

0-10 16$6N age groups. E coli infections )ere more common in 21-30 3$N follo)ed !y 31-

40 2N age groups$ K pneumoniae infections )ere more common in males and E coli

infections )ere more common in females$



K pneumoniae isolates )ere completely resistant to aminopenicillin 100N$

o)e*er# t"ey s"o)ed *aria!le resistance to cep"alosporins 11$6N - 30N# tetracycline 60$0N#

norflo,acin 0$0N# cotrima,a+ole 46$6N$ E coli s"o)ed 20N resistance to aminopenicillin and

2N resistance to 1st and 2nd generation cep"alosporins$ (ll K pneumoniae and E coli isolates )ere

suscepti!le to piperacillin ta+o!actum# imipenem and amiacin$ (mong aminoglycosides# amiacin

s"o)ed !est suscepti!ility in our study$

(mongst 100 entero!acteriaceae isolates# .S/ production )as ma,imally 6$0N

detected !y p"enotypic confirmatory met"od (P-($ Dou!le dis synergy test )as a!le to

detect .S/ production in 4$0N isolates !y using (-%C and in $0N isolates !y using =I%-

=$ (ll isolates detected as .S/ positi*e !y dou!le dis synergy test !y using eit"er of t"e

met"ods "a*e s"o)n .S/ production !y p"enotypic confirmatory met"od also$

(mongst 100 entero!acteriaceae isolates# (mp production )as e&ually detected

!y !ot" cefta+idime-imipenem dis antagonism test and cefo,itin-cefota,ime dis antagonism test

2$0N$

β-lactamase production )as o!ser*ed in entero!acteriaceae isolates$ .S/ )as

o!ser*ed in 6 6$0N isolates and (mp production in 2 2$0N isolates$ 8one of t"e strains )ere

positi*e for /$ .S/ production )as seen in N of E coli strains and 6$6N of K pneumoniae

isolates maing 6N in entero!acteriaceae strains studied$ (mp production )as seen in 2N of K

pneumoniae isolates and not seen in E coli isolates$ %"us in total 9N of t"e E coli and K

pneumoniae isolates s"o)ed !eta-lactamase production$



@. References

1$ /allo)s (# ausler @ F Fr# errmann # Isen!erg D# S"adomy F eds anual of

linical icro!iology 1;;1# t"

ed# pp 361-4$

2$ /auer (@# ir!y @# S"erris F# %urc $ (m F lin =at" 1;66E 4:4;3-6$

3$ /lac F(# oland .S# %"omson S$ (mp dis test for detection of plasmid-mediated

(mp β-lactamases in entero!acteriaceae lacing c"romosomal (mp β-lactamases$ F lin

icro!iol 200E 43: 3110-3$

4$ /us" # Faco!y 7(# edeiros (($ ( functional classification sc"eme for β-

lactamases and its correlation )it" molecular structure$ (ntimicro!ial (gents

"emot"erapy 1;;E 3;: 1211-33$

$ antarelli <<# .*erton Inamine .# /rodt %P# Secc"i # a*alcante /# =ereira BS$

Atility of t"e cefta+idime-imipenem antagonism test I(% to detect and confirm t"e

presence of induci!le (mp !eta-lactamases among entero!acteriaceae$ /ra+ F

Infect Dis 200E 11: 23-;$

6$ astellani (# "almers (F$ anual of tropical medicine# 3rd

.d# @illiams )ood o$#

8e) Tor# 1;1;$

$ "easty %# Smit" R$ Escherichia$ In /orriello S=# urray =R# Bune 7 eds$$ %opley

@ilson>s icro!iology icro!ial Infections# <ol$2# 10t"

.d# odder (rnold# Italy# 200#

p 13;-91$

9$ SI 2012: =erformance standard for (ntimicro!ial Suscepti!ility %estingE 100- S22# 32

:$3# @ayne# AS($

;$ ric"ton =/$ .ntero!acteriace: .sc"eric"ia# le!siella# =roteus and ot"er genera$ In



ollee F7# Braser (7# armion /=# Simmons ( eds acie cartney practical

medical micro!iology 200# 14t"

edition# "urc"ill i*ingston# Del"i# pp 361-94

10$ Donnen!erg S$ .ntero!actereacae$ In andell 7# /ennett F.# Dolin R eds andell#

Douglas# and /ennetts principles and practices of infectious diseases# 6t"

ed$ "urc"ill

i*ingstoneE ="iladelp"ia p$26-96$

11$ .sc"eric" %$ Die Darm!aterien des 8eugerufen and Suglings$ Borstsc"r ed 199E 3:

1-22# 4-4$

12$ 7uillermo <$Sanc"e+# Spencer F$.$ (dams# (le,is $7$ /aird# Ronald 8$ aster#

Ric"ard /$ lar and Fose $ /ordon#$ .sc"eric"ia Escherichia coli antimicro!ial

resistance increased faster among geriatric outpatients compared )it" adult outpatients in

t"e AS(# 2000G10# Fournal of (ntimicro!ial "emot"erapy 2013# 69 9: 1939-1941

13$ 7upta <# umarasamy # 7ulati 8# 7arg R# ris"nan =# "ander F$ (mp β-lactamases

in nosocomial isolates of Klebsiella pneumoniae from India$ Indian F ed Res 2012E 136:

23-41$

14$ "ttp:JJen$)iipedia$orgJ)iiJle!siella

1$ Faco!y 7($ (mp β-lactamases$ lin icro!iol Re* 200;E 22: 161-92$

16$ Far*is @R# oon <=# ig"smit" ( et al$ %"e epidimiology of nosocomal infections

caused !y le!siella pneumoniae$ Infectontrol 1;9E 6E 69-4$

1$ "an R# %"ural SS# 7aind R$ .*aluation of a modified dou!le-disc synergy test for

detection of e,tended spectrum β-lactamases in (mp β-lactamase-producing Proteus

mirabilis$ Indian F ed icro!iol 2009E 26: 9-61$

19$ umarasamy # %oleman (# @als" %R# et al $ .mergence of a 8e) (nti!iotic

Resistance ec"anism in India# =aistan# and t"e A: ( olecular# /iological# and

http://en.wikipedia.org/wiki/Klebsiella

http://en.wikipedia.org/wiki/Klebsiella



.pidemiological Study$ ancet Infect Dis 2010E 10: ;-602$



32

1;$ a"es" .# ed"a T# Indumat"i <(# umar =S# "an @# =unit" $ ommunity-

ac&uired urinary tract infection in t"e elderly$ /F= 2011E 4: a406$

20$ anual of )ors"op on detection of !eta-lactamases: p"enotypic and genotypic met"ods$

5rgani+ed !y Department of icro!iology# Institute of edical Sciences# /anaras indu

Ani*ersity# <aranasi$ In CCC< 8ational onference of Indian (ssociation of edical

icro!iologists# IR558 2011# <aranasi$

21$ o"anty S# apil (# Das /# D"a)an /$ (ntimicro!ial resistance profile of nosocomial

uropat"ogens in a tertiary care "ospital$ Indian F ed Sci 2003E : 149-4$

22$ 8oyal F#$ene+es 7(# aris" /8# Su'at"a S# =ari'a S$ Simple screening tests for

detection of car!apenemases in clinical isolates of nonfermentati*e 7ram-negati*e

!acteria$ Indian F ed Res 200;E 12;: 0-12$

23$ =erformance standards for antimicro!ial suscepti!ility testingE t)enty-second

informational supplement$ linical a!ortory Standards Institute SI 2012$

24$ ="ilippon (# (rlet 7# Faco!y 7($ =lasmid-determined (mp type β-lactamases$

(ntimicro!$ (gents "emot"er 2002E 46: 1G11$

2$ =itout FDD# Reis!ig D# <enter .# "urc" D# anson 8D$ odification of t"e

dou!le-dis test for detection of entero!acteriaceae producing e,tended-spectrum and

(mp β-lactamases$ F lin icro!iol 2003# 41: 3;33-$

26$ Rodrigues # Fos"i =# Fani S# (lp"onse # Rad"aris"nan R# e"ta ($ Detection of β-

lactamases in nosocomial gram negati*e clinical isolates$ Indian F ed icro!iol 2004E

22: 24-0$

2$ Ruppe .# /idet =# <erdet # (rlet 7# /ingen .$ Birst detection of t"e (m!ler class 1

(mp β-lactamase in Citrobacter freundii !y a ne)# simple dou!le-dis synergy test$ F

lin icro!iol 2006E 44: 4204-$



29$ S"i!ata 8# Doi T# Tamane # Tagi %# uroa)a # S"i!ayama # ato # ai #

(raa)a T$ =R typing of genetic determinants for metallo-β-lactamases and integrases

carried !y gram-negati*e !acteria isolated in Fapan$ F lin icro!iol 2003E 41: 40-13$

2;$ S"o!"a # 7o)ris" Rao S# Sugand"i Rao# Sree'a $$ =re*alence of e,tended spectrum

!eta-lactamases in urinary isolates of Escherichia coli# Klebsiella and Citrobacter species

and t"eir antimicro!ial suscepti!ility pattern in a tertiary care "ospital$ Indian Fournal for

t"e =ractising Doctor 200E 3: 8o$ 6 200-01 - 200-02

30$ S"o!"a # Ramac"andra # Rao 7# a'umder S# Rao S=$ .,tended spectrum !eta-

actamases .S/ in gram negati*e !acilli at a tertiary care "ospital$ F clin diag res

200;E 3: 130-12$

31$ %an %T# 8g ST# e F# o" %# su T$ .*aluation of screening met"ods to detect

plasmid-mediated (mp in Escherichia coli# Klebsiella pneumoniae# and Proteus

mirabilis. (ntimicro!$ (gents "emot"er 200;# 3: 146-;$

32$ %ane'a 8# Rao =# (rora F Dogra ($ 5ccurrence of .S/ (mp- β-lactamases

suscepti!ility to ne)er antimicro!ial agents in complicated A%I$ Indian F ed Res 2009E

12: 9-99$

33$ %ato # orosini # 7arcia # (l!erti S# o&ue %# anton R$ ar!apenem

"eteroresistance in <I-1-producing Klebsiella pneumoniae isolates !elonging to t"e same

clone: conse&uences for routine suscepti!ility testing$ F lin icro!iol 2010E 49: 409;-;3$

34$ Arinary %ract Infections# Ani*ersity of aryland# edical enter$

"ttp:JJumm$eduJ"ealt"JmedicalJreportsJarticlesJurinary-tract-infection$

3$ @als" %R$ .merging car!apenemases: ( glo!al perspecti*e$ Int F (ntimicro! (gents 2010E

36 Suppl 3: 9-14s$

http://umm.edu/health/medical/reports/articles/urinary-tract-infection

http://umm.edu/health/medical/reports/articles/urinary-tract-infection

Study of drug resistance and beta-lactamse production in clinical isolates of E coli and Klebsiella

Documents

Transcript of Study of drug resistance and beta-lactamse production in clinical isolates of E coli and Klebsiella