Susceptibility testing of pink-pigmented facultative methylotrophic (PPFM) bacterial isolates to selected antimicrobials

• Main Author: Ongbin, Tanya Robert D.
• Format: text
• Language: English
• Published: Animo Repository 2008
• Subjects: Food additives; Anti-infective agents; Bacteria; Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/2192
• Institution: De La Salle University

One hundred twenty (120) isolates of pink pigmented facultative methylotrophic bacteria deposited at the Microbiology Laboratory of De La Salle University Manila were subjected to disk diffusion method and minimum inhibitory concentration determination. The isolates were obtained from various environmental sources specifically from air, plants, creek water and soil. The guidelines recommended by Clinical Laboratory Standards Institute (CLSI, 2007) for Enterobacteriaceae was adapted. Modifications in the protocol include the incubation period of 3-7 days, at 30oC and the use of glycerol peptone agar as the culture medium. Majority of the isolates were resistant to meropenem, ampicillin and ciprofloxacin, susceptible to augmentin, and intermediately susceptible to cefotaxime. Almost all of the isolates were highly susceptible to doxycycline and imipinem. MICs of more than half of the isolates to the antimicrobials (in g/ml) were as follows: ampicillin, augmentin, cefotaxime, ciprofloxacin, meropenem,tobramycin. Multiple drug resistance among the Methylobacterium isolates were detected with some possible ß-Lactamase producing strains. Almost all isolates exhibited discordant carbapenem susceptibility, showing resistance to meropenem and susceptibility to imipinem.