Table 7-3 will familiarize you with commonly
encountered bacteria. This table lists the bacterias
morphologic shape, Gram stain response, genus and
species, and the type of infection it produces.
BACTERIOLOGIC METHODS
There are a variety of methods used in the
laboratory to identify bacteria. However, only a few of
these bacteriologic methods can be performed in
isolated duty locations or on board naval vessels. One
of these methods is the smear. The smear permits
healthcare personnel to examine specimens
microscopically.
Material requirements and the
step-by-step procedures for making smears is covered
in the following sections.
Smear
A smear is the procedure in which a specimena
body fluid or a dischargeis spread across a glass slide
for microscopic examination.
To enhance the
visualization of microorganisms on the smear, Gram
staining (introduced earlier in this chapter) is used.
Once the smear is stained, it is ready to be examined
under the microscope. Normally, smears are examined
by laboratory technicians who prepare reports of their
findings.
MATERIALS REQUIRED FOR SMEAR.To
perform a smear, the following materials are required:
Glass slide
7-27
COMMON BACTERIA
Morphologic
Shape
Gram-
Positive or
-Negative
Genus & Species
Type of Infection
Streptococcus pneumoniae
Pneumonia
Positive
Streptococcus pyogenes (Beta
Streptococci Group A)
Strep throat
Cocci
Staphylococcus aureus
Boils, furuncles, osteomyelitis,
pneumonia, septicemia,
endocarditis, and impetigo
Neisseria gonorrhoeae
Gonorrhea
Negative
Neisseria meningitidis
(meningococcus)
Meningitis
Corynebacterium
diphtheriae
Diphtheria
Bacilli
Positive
Clostridium
(all are anaerobic and
spore producers)
perfringens (welchii)
tetani
botulinum
Gas gangrene
Tetanus
Botulism
Yersinia (Pasteurella) pestis
Bubonic plague
Negative
Brucella abortus
Brucellosis
Bordetella pertussis
Whooping cough
Table 7-3.Common Bacteria