Anaerobic (Bacterial Culture)

ANAEROBIC (BACTERIAL) CULTURE SPECIMEN COLLECTION

All specimens submitted to the laboratory should be labeled with at least two patient identifiers:

• Patient name
• Medica Record Number or Date of Birth

The samples should also be labeled with:

• The specimen type
• The collection date and time
• The collector's initials or employee ID number

 

Appropriate personal protective equipment (PPE) must be used during all collection procedures. Refer to department policies or Infection Control for more information.

 

Introduction

Specimens for anaerobic culture should be collected at the site of infection, from anatomic regions that support the growth of anaerobes, with sterile technique, avoiding areas that are heavily contaminated with normal microbiota. The preferred sample types for anaerobic culture are aspirates (collected with a needle and syringe) and tissue/biopsy samples. The collection of samples with swabs is discouraged, but swab samples will not be rejected (unless they are from an unacceptable site, see below). 

Any samples submitted for anaerobic culture will also have an aerobic culture and Gram stain performed. The Microbiology laboratory will not process an anaerobic culture as a standalone test. 

 

Equipment/Supplies:

• Sterile cup
• Disinfectant (betadine, chlorohexidine, povidone-iodine)
• Sterile gauze
• Sterile syringe
• Sterile needle
• Sterile small, plastic flexible catheter
• ESwab collection kit 
  • Note: 1 Eswab from the same site can be used for aerobic, anaerobic, and fungal cultures.

 

Specimen Collection

Aspirates, Abscesses, and Fluids:

1. Clean the surface area of the intact tissue with disinfectant solution.
2. Use a needle (or flexible plastic catheter) and syringe to aspirate fluid (or pus) from the area. 
3. Send the sterile syringe to laboratory after detaching the needle or transfer sample into sterile specimen cup and sent that to the laboratory.

 

Tissue

1. Disinfect surface area of the skin.
2. Excise infected tissue.
3. Transfer into sterile cup for transport.

 

Sinus Tracts and Deep-Wound Drainages

1. Disinfect the skin surface
2. Submit for culture one of the following:
   • Aspirate material using a small flexible plastic catheter
   • Curettage samples from deep within the tract or wound.

 

Decubiti and other surface ulcers

1. Thoroughly disinfect the skin surface.
2. Submit for culture one of the following:
   • Punch biopsy
   • Material aspirated with a needle and syringe
   • Curettage samples obtained from deep within the wound margin.

 

Pulmonary Specimens

1. Submit one of the following for culture:
   • Lung tissue collected percutaneously or via endotracheal collection.
   • Bronchial brushings collected with a double lumen catheter or trans-trachael aspirate.

 

Female Genital Tract Samples

1. Disinfect the cervical opening.
2. Sample the upper genital tract using a double-lumen collector.
3. Specimens collected by laprascopy, culdocentesis, and surgery are acceptable for anaerobic culture.
4. Culture of intrauterine devices will only be performed if approved by the Microbiology Medical Director.

 

Orthopedic Samples

1. Synovial fluids should be collected aseptically and submitted for anaerobic (and aerobic) culture.
2. Culture of any hardware device will only be performed with the approval of the Microbiology Medical Director. 

 

Transport

1. All samples submitted for anaerobic culture should be sent to the laboratory immediately.
   • Samples should arrive within two hours of collection for optimal anaerobic organism recovery. 

 

 

Last updated 11/20/2025

 

References:

• Bowden, V.R., Smith Greenberg, C. (2008). Pediatric Nursing Procedures, 2nd Ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.
• Clinical Microbiology Procedures Handbook, 5th Edition. 2023. Washington, D.C.: The ASM Press.
• Dickinson and Company, Sparks, Maryland, 08/2016 Becton, technical insert #0086ESwab
• Jorgensen, James. Manual of Clinical Microbiology 11th Edition, ASM Press 2015

Acceptable Material	Unacceptable Material
Aspirate (by needle and syringe)	Bronchoalveolar lavage washing (except OR specimens)
Bartholin's gland inflammation and secretions	Cervical secretions
Blood (Venipuncture)	Endotracheal secretions
Bone Marrow (aspirate)	Lochia secretions
Bronchoscopic secretions	Nasopharyngeal swabs
Culdocentesis fluid (aspirate)	Perineal swab
Fallopian tube fluid or tissue (biopsy/aspirate)	Prostatic or seminal fluid
IUD for Actinomyces	Sinus washings or swab
Nasal sinus (aspirate)	Sputum
Placenta tissue (cesarean delivery)	Stool or rectal specimen
Pilondial cyst abscess	Tracheostomy secretions
Surgical site (aspirate)	Urethral secretions
Transtracheal aspirate	Urine other than suprapubic
Urine (suprapubic aspirate)	Vaginal secretions/swab
Surgical specimens and specimens collected by endoscopic procedure
Retropharyngeal abscess