Staphylococci that are resistant to methicillin and oxacillin should also be considered clinically resistant to cefoxitin even if they test susceptible by in vitro methods.Major bacterial strains susceptible to cefoxitin include:
methicillin-susceptible Staphylococcus aureus
Streptococcus sp. E. coli
Salmonella sp. Proteus vulgaris
Flavobacterium sp. Klebsiella sp.Major bacteria resistant to cefoxitin include:
methicillin-resistant Staphylococcus aureus
Enterococci
Listeria monocytogenes
Enterobacter sp. Bacteroides sp. Replacement and substitution
In a 2005 study, Fernandes et al. determined that cefoxitin serves as an appropriate replacement for methicillin in determining if some bacteria display methicillin resistance. Likewise, Funsun et al. found in a 2009 study that cefoxitin disk assays correctly identified all 60 mecA-positive Staphylococcus aureus, or MRSA isolates, to be resistant to cefoxitin.Due, in part, to the unavailability of methicillin in the United States, cefoxitin has replaced methicillin for disk diffusion tests, which determine the sensitivity of a bacterial specimen to a given antibiotic. Cefoxitin also yields more accurate results for disk diffusion tests. Interpretive criteria for determining susceptibility to cefoxitin via disk diffusion are greater than or equal to 22mm resulting in a "susceptible" result for Staphylococcus aureus and greater than or equal to 25mm for coagulase-negative staphylococci to be considered susceptible.The following are susceptibility data for several medically significant microorganisms, measured by minimum inhibitory concentration, which is an alternative, liquid medium test for susceptibility. Escherichia coli: 0.2 μg/ml – 64 μg/ml
Haemophilus influenzae: 0.5 μg/ml – 12.5 μg/ml
Streptococcus pneumoniae: 0.2 μg/ml – 1 μg/ml

Uses in medicine
Cefoxitin is sold in three major IV doses, 1g, 2g, and 10g.
Cystic fibrosis is a disease which causes mucus buildup in various organs. Evidence has shown that cystic fibrosis affects multiple systems in the human body, including the reproductive system. Around 97-98% of people with cystic fibrosis who have testicles are infertile due to a missing vas deferens, the tube in the male-assigned reproductive system that carries sperm out of the testes. Additionally, cystic fibrosis can result in the atrophy of male-assigned reproductive organs by causing dehydrated secretions. Diagnosis
Physical examination
A healthcare provider may initially assess size and shape as well as firmness and texture of the testicles. Ultrasonography
Ultrasonography is used to detect testicular volume. Testicular volume measured to be less than 12 mL is a sign of testicular atrophy. In addition, testicular atrophy can be recognized as greater than 50% loss of testicular volume or a post-operative testicle with less than 25% of the volume of the opposite testicle. Lab tests
Assessment of testicular function is also dependent on lab tests. Low testosterone is a potential cause of testicular atrophy, and laboratory values of blood samples can confirm low free or bioavailable testosterone.Due to the high levels of oxidative stress in the semen, there may also be higher levels of sperm DNA fragmentation for people with varicoceles. In some cases, people with testicular damage who do not undergo repair of the varicoceles will have testicular atrophy.