Gram Positive

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description

Corynebacterium Spp. Clostridium spp. Listeria spp. Bacillus spp. Gram Positive. Bacilli. Cocci. Catalase negative Streptococcaceae ( strepto - cocay -see-eye). S. viridans , S. Mutans , S. sanguis Optochin resistant Bile-insoluble No capsule. Catalase positive Staphylococcus. - PowerPoint PPT Presentation

Transcript of Gram Positive

Page 1: Gram Positive
Page 2: Gram Positive

Gram Positive Bacilli

Cocci

Corynebacterium Spp.Clostridium spp. Listeria spp.Bacillus spp.

Catalase negativeStreptococcaceae(strepto-cocay-see-eye)

γ (gamma)-hemolytic EnterococcusE. faecalisE. faecium

β-hemolytic (clear) S. Pyogenes Group ABacitracin sensitive

S. agalactiae Group BBacitracin resistant

α-hemolytic (green)S. Pneumoniae Optochin sensitiveBile-soluble capsule (Quellung)

S. viridans, S. Mutans, S. sanguisOptochin resistantBile-insoluble No capsule

Catalase positiveStaphylococcus

Coagulase positive

Coagulase negative

S. epidermidisNovobiocin sensitive

S. saprophyticusNovobiocin resistant

S. aureus

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Methods

Nasopharyngeal and oropharyngeal swabs were plated onto CNA (colistin–nalidixic acid) agar (Biolife), sheep blood agar (Biolife) and Sabouraud dextrose agar (Biolife).

Sabouraud plates were incubated at 36 C in ambient air,

whereas CNA and sheep blood plates were incubated at

1. 36 C in ambient air,

2. anaerobically

3. and in an atmosphere of 5% CO2.

All plates were examined after 24, 48 and 72 h.

After 24 h of incubation, α-haemolytic colonies belonging to the same streptococcal species had grown, under each of the three atmospheric growth conditions. The isolate was identified as S. pneumoniae. (Vitek2; bioMe´rieux), and confirmation of the identification was provided by inhibition of the isolate by optochin.

Optochin susceptibility testing was performed in ambient air, anaerobically and in an atmosphere of 5% CO2, to prevent misidentification of Streptococcus pseudo-pneumoniae as true S. pneumoniae (Balsalobre et al., 2006).

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In Kirby-Bauer testing, white wafers containing antibiotics are placed on a plate of bacteria. Circles of poor bacterial growth surround some wafers indicating susceptibility to the antibiotic