Lab Anim Res.  2012 Jun;28(2):141-145. 10.5625/lar.2012.28.2.141.

Monitoring of antibiotic resistance in bacteria isolated from laboratory animals

• Goo JS
• Jang MK
• Shim SB
• Jee SW
• Lee SH
• Bae CJ
• Park S
• Kim KJ
• Kim JE
• Hwang IS
• Lee HR
• Choi SI
• Lee YJ
• Lim CJ
• Hwang DY

• KMID: 1436716
• DOI: http://doi.org/10.5625/lar.2012.28.2.141

Abstract

The drug resistance of microorganisms isolated from laboratory animals never treated with antibiotics is being reported consistently, while the number of laboratory animals used in medicine, pharmacy, veterinary medicine, agriculture, nutrition, and environmental and health science has increased rapidly in Korea. Therefore, this study examined the development of antimicrobial resistance in bacteria isolated from laboratory animals bred in Korea. A total of 443 isolates (7 species) containing 5 Sphingomonas paucimobilis, 206 Escherichia coli, 60 Staphylococcus aureus, 15 Staphylococcus epidermidis, 77 Enterococcus faecalis, 27 Citrobacter freundii, 35 Acinetobacter baumannii were collected from the nose, intestine, bronchus and reproductive organs of ICR mice and SD rats. Of these species, Acinetobacter baumannii and Enterococcus faecalis showed significant antimicrobial resistance according to the minimum inhibition concentration (MIC) in E-test. In case of Acinetobacter baumannii, several isolates showed MIC values 16-128 microg/mL for cefazolin and cefoxitin, and higher resistance (128-512 microg/mL) to nitrofurantoin than that of standard type. Resistance to cefazolin, cefoxitin and nitrofurantoin was detected in 17.14, 20.00, and 8.57% of the Acinetobacter baumannii isolates, respectively. In addition, 44.1% of the Enterococcus faecalis isolates collected from the laboratory animals were resistant to oxacillin concentration of 16-32 microg/mL range, while MIC value of standard type was below oxacillin concentration of 6 microg/mL. These results suggest that in rodent species of laboratory animals, Acinetobacter baumannii are resistance to cefazolin, cefoxitin and nitrofurantoin, whereas those of Enterococcus faecalis were resistance to oxacillin.

Keyword

Drug resistance; Enterococcus faecalis; Acinetobacter baumannii; oxacillin; nitrofurantoin

MeSH Terms

Acinetobacter baumannii
Agriculture
Animals
Animals, Laboratory
Anti-Bacterial Agents
Bacteria
Bronchi
Cefazolin
Cefoxitin
Citrobacter freundii
Drug Resistance
Drug Resistance, Microbial
Enterococcus faecalis
Escherichia coli
Intestines
Korea
Mice
Mice, Inbred ICR
Nitrofurantoin
Nose
Oxacillin
Pharmacy
Rats
Rodentia
Sphingomonas
Staphylococcus aureus
Staphylococcus epidermidis
Veterinary Medicine
Anti-Bacterial Agents
Cefazolin
Cefoxitin
Nitrofurantoin
Oxacillin

Figure

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  Figure 1 MIC test of Enterococcus faecalis resistance to oxacillin. The drug resistance isolates were sensitive in range from 16 to 32 µg/mL of oxacillin, even though the standard microorganism (ATCC 5199) was quite sensitive to more than 6 µg/mL of oxacillin. (A) Oxacillin resistance of Enterococcus faecalis isolates collected from ICR mice or SD rats. (B) Oxacillin sensitivity of Staphylococcus aureus and Staphylococcus epidermidis isolates collected from ICR mice or SD rats.

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