Clinical Microbiology

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Clinical Microbiology

• 2008

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Microorganisms as causative agents of infections
in animals

• Companion animals
• Dog and cat
• Horse
• Food animals
• Cattle and sheep
• Pig
• Poultry

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Infections of the..

• Respiratory system
• Nervous system (CNS)
• Gastro-intestinal tract
• Urinary tract
• Genital systém
• Skin, soft tissues and wounds
• Joint and bones

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Clinical microbiology (microbes and
antimicrobials)

• Bacteriology
• and use of antibiotics and chemoterapeutics)
• Virology
• And use of antivirotics
• Mycology
• And use of antimycotics
• Use of vaccines

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Clinical specimens

• Colleted from living animals not from necropsy

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Characterisation of bacteria from clinical
specimens

• Processing of a specimen
• Gram stain
• Cultivation
• Atmosphere (A/AN, ACO2,AN,A)
• Culture media (solidBA, MC agar,XLD agar,
  chocolate agar, liquid broths)
• Identification
• G
• Gram- negative bacteria (oxidase, catalase,
  biochemical tests, serological tests to identify
  serovars

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Further identification -Typing methods

• Serological tests are used for serotyping
• (E.coli O157 H7, E. coli O141 F4
• S. Typhimurium O 1,4,5,12,H i, 1,2
• S. Enteritidis O1,9,12, Hg,m
• Bacteriophage typing (S. Typimurium DT 104)

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Identification subtyping methods

• DNA subtyping methods
• gene typing for virulence factors instead of
  toxin production
• E.coli
• P. multocida

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Obligate anaerobic bacteria

• Bacteroides/Fusobacterium
• Porphyromonas
• Prevotella
• Clostridium perfringens
• Clostridium difficile

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Metods for detection of non-cultured bacteria

• Microscopy
• PCR detection using various modifications
• PCR
• Nested PCR
• Real time PCR

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Non-cultured bacterial genera and species

• Lawsonia intracellularis
• Chlamydophilla spp.
• Rickketsias
• Hemomycoplasmas
• Mycoplasma hemosuis, M. hemofelis

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G- bacterial species most frequently obsereved

• Psudomonas aeruginosa
• E. coli
• Other coliforms (Klebsiella, Enterobacter)
• Salmonella
• Pasteurella multocida
• Haemophilus spp.
• Actinobacillus spp.

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G bacterial species most frequently obsereved

• Beta haemolytic streptococci
• Staphylococcus aureus/S.intermedius
• Coagulase negative staphylococci
• Enterococci
• Clostridium perfringens

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Zoonotic bacterial species

• Campylobacter jejuni, C.coli
• VTEC (verotoxigenic E.coli serogroup O157
• Salmonella enterica (ST DT 104)
• Yersinia enterocolitica
• Streptococcus suis 2
• Listeria moncytogenes

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Mycotic infections

• Candida albicans
• Dermatophyta

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Use of Antibiotics

• Antibiotic susceptibility testing
• MIC minimum inhibitory concentrations
• Disc susceptibility test
• Etest
• Beta-lactamase test

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Commonly used antibiotic

• Range of action
• Very good
• Good
• Poor activity against particular bacteria
• Bacterial resistance mechanisms

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Betalactams

• PENICILLINS
• Benzylpenicillin
• Aminopenicillins
• Ampicilin, amoxicilin

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Cephalosporines 1 to 4 generation

• 1g cephalotin
• 2g cefuroxim
• 3g ceftazidim
• 4g cefquinom

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Carbapenems

• Imipenem

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Inhibitors of beta-lactamases

• Clavulanic acid
• Sulbactam
• Combination co-amoxicillin

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Glykopeptides

• Vancomycin
• Teicoplanin

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Aminoglycosides

• Streptomycin
• Gentamicin

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Macrolides

• Erytromycin
• Tylosin
• Tilmicosin

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Lincosamides

• Lincomycine

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Tetracyclines

• Oxytetracycline/Chlortetracycline
• Doxycycline

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Amphenicols

• Chloramphenicol
• 2.gen.
• Florfenicol

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Pleuromutilins (diterpens)

• Tiamulin
• 2gen.
• Valnemulin

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Chemoterapeutics

• Sulfonamides
• Quinolones

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Sulfonamides

• Sulfamethoxazol
• Co- trimoxazol

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Quinolones

• Non fluorinated q.
• Oxolinic acid
• Fluorinated q.
• enrofloxacin

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Infections of the Respiratory System

• Mirobes
• Pathogenesis (aspiration)
• Nasopharynx
• Pharynx (pharyngitis)
• Trachea
• Bronchi (bronchioli)
• Lungs -pneumonia
• Bronchopneumonia
• Pleura (pleuritis)
• Lung absces

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Infection of the skin and sof tissues

• A breatch of the skin
• Via minor abrasions
• Hair follicles
• Surgical incision
• Wounds (traumatic, surgical)

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Infections of the blood

• Bacteraemia - bacteria in the blood se detected
  by blood culture
• Transient (single episode)
• Intermittent
• Continuous