The purpose of performing Microbiology tests is to detect from the patient sample the germs that cause infectious diseases. The techniques used to do this include Culture and Sensitivity testing, PCR/Molecular Diagnostics techniques, microscopy, serology or antigen detection techniques.

Culture and Sensitivity.

When the patient sample is inoculated on a growth plate in the laboratory with the germs are allowed to grow and then tested against the antibiotics to tell which drugs kill them or stop them from growing, this process is known as Culture and Sensitivity Testing. Example is in urine culture and sensitivity to detect the bacteria which cause UTI (Urinary Tract Infections).

PCR/Molecular Diagnostics.

Sometimes, we look for the DNA or RNA of the disease-causing germ in the patient sample using PCR/Molecular Diagnostics techniques. Example is TB PCR on sputum, HIV PCR on blood, Hepatitis C virus PCR on blood, COVID-19 PCR on Nasopharyngeal samples, e.t.c.

 Other techniques.

Still other times we simply detect the germs through microscopy e.g. for malaria germs in blood, serology  or antigen techniques.


MBN Clinical Laboratories offers, seamlessly and professionally, culture and sensitivity testing services, and also performs molecular/DNA-based tests to help determine the causative germs and their susceptibility to antibiotics.

Organism group Infectious Disease Example of causative Germs/organisms
Bacteria Pneumonia Streptococcus pneumonia
Urinary tract infections (UTI) Escherichia coli, klebsiella pneumonae
Skin ulcers in children Streptococcus pyogenes
Otitis media Staphylococcus aureus, haemophillus influenzae
Tuberculosis  (TB) Mycobacterium tuberculosis
Typhoid Salmonella Typhi or Paratyphi
Syphilis Treponema pallidum
Brucellosis Brucella mellintensis or B. Abortus
Dysentery (bloody diarrhoea) Shigella dysenterae
Bacterial Meningitis Streptococcus pneumoniae, Nesseria meningitidis
Peptic ulcers Helicobacter pyroli
Pyomyositis Staphylococcus aureus
Osteomyelitis Staphylococcus aureus
Gonorrhea Nesseria gonorrhae
Blood stream infection Staphylococcus aureus, salmonella spp
Viruses Naso-pharyngitis (Sore throat/flu) and pneumonia SARS-CoV-2 Virus (COVID-19), Influenza, Measles, etc
Painful ulcers in genital parts Herpes simplex virus (HSV) Type 2
Genital warts Molluscum contagiosum
Viral Meningitis Herpes simplex virus (HSV) type 1
Blood stream viral infections Cytomegalovirus (CMV)
Skin infections Molluscum contagiosum
Fungi Nails/Hair/Skin fungal infections in children/adults Many species of fungi cause these
Vaginal candidiasis Candida albicans
Blood stream fungal infections Candida albicans – in patients with blood/bone marrow cancer
Fungal Meningitis Cryptococcus neorfomans
Disseminated organ fungal infections Several Dimorphic fungi
Parasites Malaria Plasmodium falciparum or other species
Intestinal hookworm disease Hook worms
Intestinal tape worm disease Taenia saginata,  or T solium
Trypanosomiasis Trypanosoma gambience
Filariasis (River blindness or Elephantiasis) Oncocerca volvulus
Schistosomiasis Schistosoma haematobium, S. Mansoni
Persistent Diarrhoea Cryptosprodium parvunm or other species
The MBN Automated Blood Culture System on the BACTEC FX40 Instrument



Ascites/Pleural/Joint/Pericardial/Hydrocele Fluids (10-20 mls in sterile tube)

Cell counts, Gram, ZN, Protein, Sugar, LDH

Culture & Sensitivity


Biopsy tissue

Gram and ZN stain

KOH + Calcoflour (fungal hyphae)

Culture & Sensitivity (Sample collected in plain sterile container with 1-2 mls sterile N.saline)

Histopathology test, collect sample in 10% Formalin

Pap Smear to screen for cancer of the Cervix



B/S Malaria/Trypanosoma/Filaria/Leishman)

Malaria antigen test (P. falc & P. ovale )

Blood culture & Sensitivity – Manual monitoring

Blood culture & Sensitivity – Automated monitoring


Bone marrow (1-2ml in sterile tube)

Bone marrow Smear/film

Culture & Sensitivity (bacteria / fungi)


Breast milk (5-10ml in sterile tube)

Gram, ZN stain, Culture & Sensitivity


BAL/Endotrachael fluid (3-5 mls in sterile tube)

Gram, ZN and Auramine stain

Giemsa stain (Pneumocyctis jirovecii/PCP)

Culture & Sensitivity (bacteria / fungi)

Mycobacterial Culture & Sensitivity


Catheter Tip (2-3cm tip, cut into 1ml sterile N/S)

Culture & Sensitivity (bacteria / fungi)


CSF  (1-3ml in sterile tube, 1ml in Fluoride bottle for Sugar)

Cell counts – T & D, India ink, Gram & ZN stain, Sugar, Protein

Culture & Sensitivity (bacteria / Yeasts e.g. Cryptococcus)

RPR/ VDRL and TPHA with titers

CRAG (Cryptococcal antigen) test


Corneal Scraping (In Sterile tube/petridish)

Gram, ZN, KOH+Calcoflour white stain

Culture for ameoba


High Vaginal /Cervical Swab

Wet prep for TV, & Gram stain for clue cells

Culture & Sensitivity(Grp B strep or Neisseria)


Gastric Aspirate/biopsy (3-5 mls or g in sterile tube)

ZN for AFBs

Culture for Helicobacter pylori or Mycobacteria


Lymph node Aspirate (3-5 mls in sterile tube)

Gram, ZN and auramine stain

Culture & Sensitivity (bacteria / fungi)

Mycobacterial Culture & Sensitivity


Nasal swab (in amies transport medium)

Culture & Sensitivity to r/o MRSA


Nasopharyngeal/Oropharyngeal swab (in amies transport medium)

Direct Agglutination test (Group A β–haem strept)

Culture & Sensitivity (Group A β-haem strept)


Pus 2-3ml in sterile tube or pus swab in amies transport medium. Body site:__________

Gram & ZN stain, Culture & Sensitivity  (bacteria / fungi)

Anaerobic Culture & Sensitivity (only for pus in tube)



Volume, PH, Spermatozoa motility, Morphology, Count

Culture & Sensitivity


Skin/Hair/ Nail Scrapping (in sterile petri dish)

KOH+ Calcoflour white stain (fungal hyphae/ yeasts)

Culture & Sensitivity for fungal diagnosis


Sputum – Coughed out/Induced (≥3ml, sterile tube)

Gram, ZN and Auramine stain

Giemsa stain (Pneumocyctis jirovecii/PCP)

Culture & Sensitivity (bacteria / fungi)

Mycobacterial Culture & Sensitivity



Stool 3-5g or mls in sterile dry tube; (If for O&P, put in 10ml of 10% Formalin)

Direct wet/iodine mount microscopy

Processed stool then iodine mount microscopy, Trichrome staining for Ova&Parasites and Modified ZN for protozoa such as Cryptosporidium oocysts)

Methylene blue test for PMN Cells

Culture & Sensitivity (Salmonella/Shigella/C.jejuni/Yersinia/Enterohaemorrhagic E. coli/H. pylori/Vibriocholerae)

Reducing sugars in stool

Sudan III test for stool fat


Urethral/Rectal Swab (collect into Modified Thayer-Martin medium or inoculate a chocolate plate immediately).

Gram, ZN stain, Culture & Sensitivity


Urine (5 -10mls in sterile tube)

Microscopy (WBCs, RBCs, epithelial cells, casts, eggs)

Gram & ZN stain on sediment

Culture & Sensitivity