Category: A

A cylinder of agar, 33 mm in diameter, in a polythene case, from which the end may be extruded to press on to a surface to obtain a viable count of the bacteria thereon. The exposed end is sliced off and incubated in a petri dish, exposed side up, and the operation repeated with the…

Blackening of aesculin – ferric citrate-peptone water agar within 7 days of inoculation-a test to differentiate between the streptococci.  

Genus of small, motile or non-motile Gram-negative rods, oxidase positive. The 0/F reaction is fermentative, distinguishing the genus from Pseudomonas. Water and sewage bacteria; food spoilage may result from heavy infestation. A genus of gram-negative, facultatively anaerobic, non-spore-forming, motile bacilli found in water and soil. They may cause wound infections or gastroenteritis in humans.  

Genus of saprophytic Gram-positive coccoid organisms growing in clusters, tetrads or short chains. Green haemolysis on blood agar, catalase weakly positive or negative, 0/F test is fermentative. Heat, salt and bile resistant.  

Bacterial genus comprising Aer. aerogenes and Aer. cloacae. The genus has now been abandoned; two different bacteria previously styled y4er. aerogenes are now termed Klebsiella pneumoniae and Enterobacter aerogenes respectively; while Aer. cloacae is now Enterobacter cloacae.  

Semi-synthetic broad-spectrum penicillin derived from the mould Cephalosporium salmosynnematum, with particular action against Gram-negative rods including S. typhi.  

The ‘higher’ bacteria. An Order of schizomycetes which has three families, i.e. Mycobacteriaceae, Actinomycetaceae and Streptomy-cetaceae. Organisms in this Order are rigid and rod-shaped or filamentous cells with a tendency to branching; usually Gram-positive.  

Family within the Actinomycetales, consisting of Gram-positive filamentous bacteria, non-septate at first, later breaking into smaller segments, rod-shaped or spherical; or remaining non-septate and producing spores on aerial hyphae. There are two genera— Nocardia and Actinomyces.  

Causative organism of bovine actinomycosis. Similar to A. israelii, but serologically distinct, more tolerant of oxygen on culture, and exhibiting differing carbohydrate fermentation reactions. A species that causes actinomycosis in cattle.  

Small aerobic Gram-negative rods, possibly filamentous on culture, associated with actinomycosis-like infection of cattle (‘Woody tongue’).