MICROBIOLOGY

The microbiology subdivision also referred to as “bacteriology” analyzes specimens to detect pathogens, cultures samples for bacterial growth, and conducts antibiotic testing on any bacteria that grows.

A wide range of tests are performed using various specimen types, including blood, urine, stool and swabs

·      CULTURE & SENSITIVITY TEST (C&S) = specimens tested are blood, urine, sputum, bodily fluids, swabs (nose, eye, ear, throat, wound, vaginal, urethral, cervical etc)

·       CHLAMYDIA TEST = specimen tested are swabs (genital, eye)

·      CLOSTRIDIUM DIFFICILE TOXIN TEST = specimen tested is stool

·      Enteric Pathogens (salmonella, shigella, campylobacter, yersinia, Aeromonas) = specimen tested is stool

·      FUNGUS (CULTURE & KOH) = specimens tested are skin, fingernails, hair, CSF, sputum, urine, vaginal swabs, tissue biopsy

·      GONORRHEA (GC) = specimen tested is genital swabs

·      GRAM STAIN (Gm Stain) = specimens tested are blood, sputum, bodily fluids, swabs

·      LEGIONELLA = specimens tested are sputum, bronchial/lung aspirates, pleural fluid

·      ORA & PARASITES (O&P) = specimen tested is stool

·      PNEUMOCYSTIS JIROVECI PNEUMONIA (PCP) = specimens tested are sputum, bronchial/lung aspirates

·      RESPIRATORY SYNCYTIAL VIRUS (RSV) = specimen tested is nasal washings

·      TUBERCULOSIS/ACID FAST BACILLI (MYOBACTERIA) – (TB/AFB) = specimens tested are sputum, urine, CSF, gastric washings, other bodily fluids, stool

·      TRICHOMONAS (TRICH) = specimen tested is genital swabs

Specimen Collection Responsibilities

NURSES collect the following = URINE, STOOL, SPUTUM, SWABS

A respiratory therapist (RT) or Physiotherapist (PT) may occasionally collect sputum if the patient produces the specimen while they are working with them

·      For paper requisitions the req and label are kept at the nursing station until the specimens are collected. For computer entries the order is entered and then put “on hold” until collected.

·      NUC may be asked to flag the patients Kardex with colored collection card reminders indicating the required specimen

ONCE THE SPECIMEN IS COLLECT THE NUC MUST;

1)  Ensure the container is labelled correctly

2)  Fill in the date/time of collection on the requisition

3)  Send the specimen and the requisition together to the lab

Cerebrospinal fluid (CSF) and bronchial washings are collected by the physician as they are specialized specimens. The physician will bring the specimen to the nursing station and may request the NUC to complete the requisition

The laboratory personnel collects venous blood samples for blood cultures (blood for C&S)

IMPORTANT NOTES

·      Two requisitions must be provided to the lab before they can collect the samples

·      For blood cultures the NUC must create a label for the container - this is the only venous blood specimen collected by lab that require the NUC to prepare the container label.

NUC ROLE IN PROCESSING MICROBIOLOLY ORDERS

·      Communicate details such as current medications such as antibiotics that may impact test results

·      For microbiology C& S testing results = preliminary results in 24 hours, and final results 2-5 days.

Handling Specimen Collection

·      Most microbiology order specimens are collected by the nurse.

·      For blood cultures once the lab receives the requisition they will come draw the patients blood and perform testing

COMPLETING THE MICROBIOLOGY REQUISITON

-       Apply correct ID label

-       Fill in analysis priority, diagnosis and history

-       Date/time: for specimens collected by the nurse/physician the date/time is written once the specimen has been collected

-       For blood cultures collected by the lab the date/time the lab is to collect is written

-       Indicate if patient is on antibiotics and write on the line provided

-       If patient is allergic to penicillin check the box

-       Check the appropriate test in the TEST REQUIRED COLUMN and the appropriate specimen in the SPECIMEN SOURCE COLUMN

** The reason for the test may be different from the actual diagnosis. For example, if the patient’s admitting diagnosis is a fractured ankle and a mid-stream urine (MSU) for culture and sensitivity is ordered then the diagnosis of a fractured ankle doesn’t give the lab any relevant reason for the test. If ? UTI (query urinary tract infection) is written in the history section it becomes clear why the test was ordered.

NOTE : labels are required for all specimen containers sent to microbiology

NOTE : notation “nurse aware” is not used for microbiology orders. It is only used when the NUC must immediately inform the nurse of a high priority order that the nurse needs to give stat meds etc

CULTURE & SENSITIVITY TESTING

C&S tests are the most frequently ordered microbiology tests and can be performed on a wide variety of specimens

Culture = specimens are “planted” into a special growth medium for 24 hours to see if bacteria grows

Sensitivity = if bacteria does grow the sample is subjected to antibiotic sensitivity testing to determine which one will be most effective in destroying it

BLOOD CULTURES

-       Blood for C&S testing are done to detect presence of bacteria in blood. If a doctor suspects septicemia/bacteremia (serious conditions that can be fatal if not treated quickly) they will order blood cultures STAT to diagnosis it

-       Lab collects venous blood for culture = two specimens are collected from two different locations of the body at the same time

EXAMPLE: blood culture x2 on order (ALWAYS involves two specimen collections even if not noted in doctors order)

·      NUC makes out 2 requisitions #1 & #2 in the space provided. Two labels are then made for each requisition for each container of blood specimen. The NUC would write #1 & #2 on the labels corresponding to the req’s. (2 reqs and 4 labels total)

·      IV antibiotics are given to treat septicemia. It is important they are given ASAP, but blood cultures must be done prior as any antibiotics in the blood stream could alter the results of the culture.

·      NUC must coordinate the collection of specimens and administration of antibiotics by communicating with the lab and the patient’s nurse – IV antibiotics should be started immediately after the specimen is drawn

·      Repeat blood cultures may be ordered after a few days of antibiotics to see if its treating the sepsis

·      IF patient is already receiving antibiotics and blood cultures are ordered the NUC must notify the lab by writing the antibiotic name on the requisition – repeat cultures wouldn’t need to be done STAT just the blood cultures ordered to diagnosis septicemia

When an order for a blood culture is received the NUC processes it by doing the following tasks;

1.   If STAT phone lab immediately and inform them of STAT, notate “lab aware” beside physicians order

2.   Once lab is informed, complete microbiology requisitions/labels and “RMO X2” next to the order. Hold onto the requisitions and give them to the phlebotomist when they come to collect. The phlebotomist will fill in the exact time of collection on the req.

3.   Transcribe to LAB SECTION of Kardex and notate “k”  next to order

Remember the lab must have the requisition in hand to draw venous blood samples.

URINE CULTURES

·      Urine obtained for C&S must be a “clean catch” or “mid-stream” as in not contaminated with skin flora

MSU= MID STREAM URINE

CSU= CATHETER SPECIMEN URINE (collected by a nurse this way if patient has indwelling bladder catheter

·      To collect MSU the patient is instructed to wash their perineal area and then void, catching urine in a container mid-stream

THE NUC PROCESSES URINE CULTURES BY;

1)  Inform nurse of order to collect urine

2)  Complete req and label, put at nursing station until collection

3)  Transcribe to lab section of Kardex

4)  Once collected make sure the container is labelled and date/time the specimen was collected on the requisition, and then send both specimen/req to lab together.

***URINE SHOULD NOT SIT AT ROOM TEMP FOR TO LONG, IF NOT PICKED UP BY PORTER OR LAB FROM OUT-BASKET, DELIVER YOURSELF