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Amphotericin B
Amphotericin B is a polyene antibiotic discovered in 1953 from the bacteria Streptomyces nodosus, in the Orinoco basin in Venezuela. Its name is derived from its amphoteric property, being able to react to both acid and base. It is insoluble at normal pH; hence it is available as a buffered colloidal solution, with sodium deoxycholate…
Antibiotic – intrinsic resistance
Enterobacterales & Aeromonas Enterobacterales and Aeromonas are intrinsically resistant to benzylpenicillin, glycopeptides, lipoglycopeptides, fusidic acid, macrolides (Except Azithromycin, effective for typhoid/paratyphoid fever and erythromycin for travellers’ diarrhoea), lincosamides, streptogramins, rifampicin, and oxazolidinones. Bacteria Beta-lactams Non-beta-lactams Klebsiella pneumonia complex,Klebsiella oxytocaRoultella sp.Citrobacter koseri,Citrobacter amalonaticus Amoxicillin, Ticarcillin Klebsiella aerogenes,Enterobacter cloacae complexCitrobacter freundiiHafnia alvei Amoxicillin, Coamoxiclav,1st generation cephalosporinsCefoxitin Serratia…
Aerococcus urinae
Aerococcus genus, a firmicute, was first identified in 1953 [Williams, 1953]. Multiple species have been identified since then; not all are human pathogens. Human pathogen Aerococcus viridans, Aerococcus urinae, Aerococcus urinae hominis,Aerococcus christensenii, (2001), Aerococcus sanguinicola. Not human pathogen Aerococcus urinae equi ( or Pediococcus urinae equi), Aerococcus suis, Aerococcus vaginalis. Laboratory identification: Aerococcus is a gram-positive coccus in clusters (like Staphylococcus), alpha-hemolytic on…
Aeromonas spp.
Aeromonas are Gram-negative bacilli, widely distributed in nature, especially aquatic environments – freshwater, brackish water, sewage system, hospital water system, and even drinking water. It can also be found in food and domestic or farm animals. The Aeromonas genus consists of more than 30 species based on DNA-DNA hybridisation and 16S rDNA relatedness. Of these 30…
Adenovirus
Introduction For high-resolution images, scroll to the bottom of the page Human adenovirus has 7 species based on their haemagglutination character.Each species was divided into serotypes based on neutralisation (e.g. A- 12,18, 31). At present, genotyping is being used to classify Adenovirus.Different species of human adenovirus have different tissue tropism. Species Tissue tropism A GI, respiratory,…
Actinotignum schaalii: a new pathogen
An emerging pathogen Actinotignum schaalii gram stain (pic Manurx27, Wikipedia) What infection does it cause, and who is mostly affected? How to identify Actinotignum schaalii in the lab? How do we treat infection caused by Actinotignum schaalii infection? Actinotignum schaalii presentation.(Youtube)
Pneumococcus – gallery
Streptococcus pneumoniae or pneumococci are gram-positive cocci in pairs, which may be capsulated. Colonies are 1-2mm, α-haemolytic and may appear as ‘draughtsman’ colonies (due to autolysis of the organisms). If incubated in anaerobic conditions, the colonies may appear larger and more mucoid. It is, like other Streptococcus spp., catalase-negative. Traditionally, a few of the properties of the pneumococcus were exploited to…
Paracoccus Yeei
Paracoccus yeei is an aerobic Gram-negative coccobacilli typically found in soil and brine. It appears as diplococci and may have a visible vacuole – giving an “O” shaped appearance. It may under-decolourise and appear as Gram-positive cocci. It is oxidase-positive and confused with Moraxella/Neisseria. Identification can be made using automated systems like VITEK-2 GN, MALDI-ToF and DNA…
Legionella Control in Healthcare
What are the Laws underpinning the Legionella control? There is a hierarchy of laws guiding the Legionella control ACOP L8:2013 The responsibility lies with the owner of the premises or the employer (this person is called the “duty holder”). They must identify and assess the risk, prepare a written scheme to control the risk, implement…