Cefamandole microbiology

# Microbiology
The bactericidal action of cefamandol (cefamandole) results from inhibition of cell-wall synthesis. Cephalosporins have in vitro activity against a wide range of gram-positive and gram-negative organisms. Cefamandol (cefamandole) is usually active against the following organisms in vitro and in clinical infections:

### Gram-positive
- Staphylococcus aureus, including penicillinase- and non-penicillinase-producing strains
- Staphylococcus epidermidis
- (beta)-hemolytic and other streptococci (Most strains of enterococci, eg, Enterococcus faecalis , are resistant.)
- Streptococcus pneumoniae

### Gram-negative
- Escherichia coli
- Klebsiella spp.
- Enterobacter spp. (Initially susceptible organisms occasionally may become resistant during therapy.)
- Haemophilus influenzae
- Proteus mirabilis
- Providencia rettgeri (formerly Proteus rettgeri )
- Morganella morganii (formerly Proteus morganii )
- Proteus vulgaris (Some strains of P. vulgaris have been shown by in vitro tests to be resistant to cefamandol (cefamandole) and certain other cephalosporins.)

### Anaerobic organisms
- Gram-positive and gram-negative cocci (including Peptococcus and Peptostreptococcus spp.)
- Gram-positive bacilli (including Clostridium spp.)
- Gram-negative bacilli (including Bacteroides and Fusobacterium spp.). Most strains of Bacteroides fragilis are resistant.
- Pseudomonas, Acinetobacter calcoaceticus (formerly Mima and Herellea spp.), and most Serratia strains are resistant to cefamandole and certain other cephalosporins.
Cefamandol (cefamandole) is resistant to degradation by (beta)-lactamases from certain members of the Enterobacteriaceae.
Quantitative methods that require measurement of zone diameters give the most precise estimates of antibiotic susceptibility. One such procedure 1 has been recommended for use with disks to test susceptibility to cefamandol (cefamandole). Interpretation involves correlation of the diameters obtained in the disk test with minimal inhibitory concentration (MIC) values for cefamandol (cefamandole).
Reports from the laboratory giving results of the standardized single-disk susceptibility test 1 using a 30-mcg cefamandol (cefamandole) disk should be interpreted according to the following criteria:
Susceptible organisms produce zones of 18 mm or greater, indicating that the tested organism is likely to respond to therapy.
Organisms of intermediate susceptibility produce zones of 15 to 17 mm, indicating that the tested organism would be susceptible if high dosage is used or if the infection is confined to tissues and fluids (eg, urine) in which high antibiotic levels are attained.
Resistant organisms produce zones of 14 mm or less, indicating that other therapy should be selected.
For gram-positive isolates, the test may be performed with either the cephalosporin-class disk (30 mcg cephalothin) or the cefamandole disk (30 mcg cefamandole), and a zone of 18 mm is indicative of a cefamandol (cefamandole)-susceptible organism.
Gram-negative organisms should be tested with the cefamandole disk (using the above criteria), since cefamandol (cefamandole) has been shown by in vitro tests to have activity against certain strains of Enterobacteriaceae found resistant when tested with the cephalosporin-class disk. Gram-negative organisms having zones of less than 18 mm around the cephalothin disk are not necessarily of intermediate susceptibility or resistant to cefamandole.
The cefamandol (cefamandole) disk should not be used for testing susceptibility to other cephalosporins.
A bacterial isolate may be considered susceptible if the MIC value for cefamandol (cefamandole) 2 is not more than 16 mcg/mL. Organisms are considered resistant if the MIC is greater than 32 mcg/mL.