Enterobacteria G-rods, facultative anaerobe, O (body), H (flagellate), K (fimbrial) antigens, many are comensals in intestine but some are potential pathogens Factors of virulence: Endotoxin, fimbrias, exotoxins Lab. detection: cultivation on BA/Endo, chromogennous media, biochemistry (enterotest), antigennous analysis, in addition to intestinal infections we also do ATB susceptibility testing Transport: often fecal-oral Therapy: cefalosporins, fluoroquinolons, aminopenicillins, carbapenems etc. Yersinia •Y. pestis •immobile •Causes 3 forms of pest: •1. bubonic pest (hit only regional lymphatic nodes) •Transducer: flea Xenopsilla cheopis, •2. pulmonary form - aspiration of the dust by ill-nursing •3. septic form • • •Y. enterocolitica •apendicitis-like syndrome, growth on CIN medium in cold, urease+ xenopsylla Salmonella sp. •Salmonella typhi •septic fever and headache, pink spots on the skin, alive in gallblader •Detection: direct – from blood and urine, agglutination, indirect – Widal reaction proof of antibodies •Therapy: fluoroquinolons, chloramphenicol, cholecystectomy in vectors is used • • • •Primary zoopathogennous salmonellas (S. enteritidis etc...) • • • •Biochemistry: production of H2S (hydrogen sulfide), disunite mannitol •Cultivation and detection: lactosis negative colonies on ENDO, on XLD/MAL/DC - black colonies, agglutination, multiply in selenite broth •Pathogenicity: diarrhoea •Source: domestic birds, eggs, salad cream, ice... •Therapy: ATB are not indicated, we use sauerkraut, yogurt, keep hygiene rules majolka-big SalmonellaXLD Genus Shigella (Sh. flexneri, sonnei, boydii, dysenteriae) •immobile, causes watery diarrhoea with tenesm, blood in stool •Epidemies from water sources – camps, social care institutes •Therapy: fluids • •Escherichia coli • •Saprophyte in intestine, patogennous are only these, with specific factors of virulence, these are divided into groups: •EPEC (enteropatogennous) - diarrhoea in children do 2 let, serotypes like O55, O126 // known as Pharaoh revenge •ETEC (enterotoxigennous) – cause travel diarrhoea •EIEC (enteroinvazive) – bloody diarrhoea •VTEC/EHEC (verotoxigennous, enterohemoragic) – intestinal bleeding, hemolytical-uremic syndrom. Most common serotype O157 •Out of intestine can cause urinary tract infections, wound infections etc. •Diagnostic: growth on ENDO -typical metal shine, lactose positive, form indol, pyr test negative, agglutination is needed in special cases •Therapy: susceptible to many antibiotics including ampicillin •Genus Enterobacter Genus Klebsiella •Mobile immobile •resistance to ampi, res. only to ampicillin •cefalosporins I. and II. gen. •Urease - urease + • •Pathogenicity: similar: urinary infections, pulmonary infections, sepsis, ability to form extended spectrum β-lactamase (ESBL), therapy: carbapenems only •Serratia marcescens •Nosocomial infections, heteroresistance to colistin • • •Genus Proteus •Cultivation: crawl in waves on medium - Rouss phenomenon •Biochemistry active, smell, urease +, in additon to P. mirabilis form indol •Pathogenicity: wound/urinary infections •Therapy: primary resistance to nitrofurantoin and colistin • • • •Genus Citrobacter •looks like salmonella, can form black colonies on XLD, ONP+ and PYR test+ bac_proteus1 G- micro-aerophile rods • •Campylobacter jejuni Helicobacter pylori • •Microscopy: G-bent rods G-curved rods •Cultivation: spec. medium with carbon 2 media: Thayer-Martin medium + control medium •Grey colonies with metal shine little transparent colonies like haemophillus •cultivation via 42˚C 48 hours 5 day cultivation •Biochemistry + resistance: •oxidase, catalase oxidase, catalase, urease •Resistant to cefalotin S to cefalotin •Susceptibility to nalidix acid R to nalidix acid •Patogenicity: diarrhoea gastritis to gastric ulcer •Therapy: •without therapy/hard infections - macrolides 3combin. amoxic.+metronidazol+bismut • amoxicillin+claritromycin+omeprazol Helicobacter H. pylori Genus Vibrio •Live in water, better grow i presence of NaCl (halophilic) + grow also in alcalic pH, susceptible to vibriostatic compound, after drop of deochycholate sodium form string (string test), oxidase • • •V. cholerae • •Microscopy: G- curved rods, with flagellum •Due to O antigen we distinguish 155 serotypes. Most common are O1 (El Tor and classic type), O139, non O1/O139 - NAG (nonagglutinable) vibria •Pathogenicity: diarrhoea looking like rice soup, vomitting •Therapy: rehydratation + chloramphenicol •Diagnostic: cultivation on TCBS agar - green colonies, membrane in alcalic pepton water, detection of serotype with help of the agglutination •Other vibria •Cause diarrhoea, wound infections • • •Aeromonas •negative string test •Not susceptible to vibriostatic compound •Cause diarrhoea, on TCŽS form yellow colonies