Microbiology services
Find out more about the range of specialist laboratory services we provide.
Bacteriology
Bacterial culture results are provided in two to three days after submission. For cases marked as urgent, preliminary results will be reported to the clinician as soon as they are available.
Alongside standard aerobic, anaerobic, capnophilic, and microaerophilic cultures, we also conduct targeted pathogen detection, including for specific organisms like Streptococcus equi equi, Salmonella spp., Bordetella spp., and Clostridium difficile, when necessary.
Where appropriate, samples are screened for methicillin resistant Staphylococcus aureus (MRSA) or S. pseudintermedius (MRSP), inducible clindamycin resistance in staphylococci and streptococci, extended spectrum β-lactamase (ESBLs) and carbapenemase-producing Gram-negative bacteria and vancomycin-resistant enterococci (VRE).
All suspected methicillin resistant staphylococci (MRSA, MRSP and coagulase-negatives) isolates can be tested by polymerase chain reaction (PCR) for confirmation of mecA or mecC carriage upon request.
Antimicrobial susceptibility testing is provided by disc diffusion and automated reading of inhibition zones (SIRScan, i2A, France) and by determination of minimum inhibitory concentrations (MICs) by broth microdilution (Sensititre OptiRead, Thermo Scientific, UK) using veterinary-specific panels relevant to small animals, equine, bovine mastitis etc.
Bacterial identification is performed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS, Bruker Daltonics) with the preliminary results, including bacterial culture findings with species identification, typically available one day after specimens arrive at the laboratory.
Interpretation of antimicrobial susceptibility testing is according to the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints.
Bacteriology testing
The bacteriology test range includes:
- Routine aerobic, anaerobic, capnophilic and microaerophilic bacterial culture
- Identification of bacterial isolates at species level
- Bacterial identification by MALDI-TOF [FZ1] MS provided for bacterial isolates submitted on agar plates by external laboratories
- Bacterial identification by 16S ribosomal RNA (rRNA) (PCR and amplicon sequencing)
- Antimicrobial susceptibility testing by disc diffusion where the reading is performed automatically with SIRScan reader
- Antimicrobial susceptibility testing with determination of minimum inhibitory concentrations (MICs) by broth microdilution using the Sensititre platform
- Targeted pathogen screening, for example MRSA/MRSP, equine strangles and Bordetella bronchiseptica
- Faecal culture (screening for Salmonella spp., Campylobacter spp., Cl. perfringens, Cl. difficile, Yersinia spp.)
- Streptococcus spp. Lancefield Group classification
- Direct smear examination (Gram staining, Ziehl-Neelsen and Modified Ziehl-Neelsen staining, India ink staining)
- Gram staining of gastric biopsy tissue for Helicobacter spp. detection.
Phenotypic and molecular methods
Phenotypic and molecular methods (see our Molecular Diagnostic services below) for the detection of antibiotic resistance mechanisms in Gram-positive and Gram-negative bacteria include:
- MRSA/MRSP detection (chromogenic media and mecA and mecC PCR-based detection)
- Inducible clindamycin resistance (including via phenotypic D-test and PCR confirmation of erm genes)
- Resistance to 3rd generation cephalosporins via extended spectrum beta-lactamase (ESBL) or AmpC production (phenotypic disc-based and genotypic PCR-based detection)
- Detection of plasmid mediated resistance to fluoroquinolones (qnr genes), carbapenems (NDM, OXA, KPC-like genes) and colistin (mcr-1 and mcr-2).
Fungal culture
Most fungal culture submissions are requests for skin and ear fungal tests, but we also provide general fungal culture testing for other specimens including post-mortem tissues.
Most commonly performed tests in our laboratory are:
- Wet preps: microscopic examination (including ringworm arthrospore identification)
- Skin scraping or hair - general fungal culture
- Yeast cultures - species level identification
- Dermatophytes - culture and identification
- Cryptococcus spp. testing (ink stain, culture and identification).
Identification of fungal isolates is performed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS, Bruker Daltonics). Occasionally, molecular identification is performed using polymerase chain reaction (PCR) which targets the internal transcribed spacer 1 (ITS1) region of the ribosomal deoxyribonucleic acid (DNA) (PCR and amplicon sequencing).
Molecular diagnostics
Our laboratory provides diagnostic PCR testing to identify and type selected infectious agents and antimicrobial resistance mechanisms, including:
- Methicillin resistant Staphylococcus aureus (MRSA), S. pseudintermedius (MRSP) or other staphylococci isolates for confirmation of mecA or mecC carriage.
- Staphylococcus aureus ST398 screening
- Streptococcus equi ssp. equi (equine strangles) detection (with or without bacterial culture & ID)
- Clostridium perfringens (biotyping, enterotoxin and β2 toxin detection)
- Clostridium difficile toxA/B detection
- Salmonella spp. Real-Time PCR directly from clinical specimen[FZ1]
- Extended spectrum β-lactamase (ESBLs, e.g. CTX-M) and plasmid-mediated AmpC (e.g. CMY and DHA type enzymes) resistance genes in Gram-negative bacterial isolates
- Carbapenemase-production (e.g. OXA, NDM and KPC type enzymes) in Gram-negative
- Combined ESBL/pAmpC/Carbapenemase-production in Gram-negative bacteria.
For antimicrobial resistance (AMR) mechanism screening, please refer also to the 'Phenotypic and molecular methods' section above on this page (section ‘Bacteriology’). You can find the associated costs for each AMR phenotypic and genotypic test in our price list.