Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand

This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.

ISOLATION OF CRYPTOCOCCUS NEOFORMANS FROM AVIAN DROPPINGS IN CHIANG MAI FROM DECEMBER 2005 TO MAY 2006

We investigated the occurrence of Cryptococcus neoformans in avian droppings collected in the Chiang Mai area and Chiang Mai Zoo, from December 2005 to May 2006. A total of 360 avian dropping samples, comprising 263 from myna, pigeon, dove and chicken in seven districts of Chiang Mai and 97 from 27 avian species in Chiang Mai Zoo, were collected and studied. Antibiotic-treated suspensions of each sample were streaked onto L-dopa agar plates for the isolation of C. neoformans. Cultures were incubated at 37° C for 10 days. Suspected smooth black pigmented colonies were identified using microscopic morphology, India ink preparation and biochemical tests. Of the 263 samples, C. neoformans was isolated from 16/61 (26.2%) pigeon droppings, 2/10 (20.0%) dove droppings and 1/189 (0.5%) chicken droppings. Of the 97 samples collected from 27 avian species in Chiang Mai Zoo, C. neoformans was isolated from 1/9 (11.1%) red-billed hornbill droppings. Environmental sources of C. neoformans in Chiang Mai are from wild pigeon and dove droppings. C. neoformans in domestic chicken droppings was a rare occurrence in this study. Among the 27 captive species in Chiang Mai Zoo, avian droppings from red-billed hornbill were positive for this fungus.