Various viral and bacterial pathogens interact with environmental factors to cause diarrhea in piglets. Enterococcus spp. are Gram-positive anaerobic bacteria that are commonly found in the gastrointestinal tract of several animal species, including pigs. Enterococcus spp. have been reported to infect several animal species as a pathogen. However, gastrointestinal infection by Enterococcus hirae is rare in pigs; only a few cases have been reported worldwide. Four piglets with diarrhea were examined in the diagnostic laboratory of Optipharm Inc. (Cheongju, Korea). During the initial post-mortem examination, no disease lesions were observed. Upon microscopic examination, we found numerous Gram-positive cocci that were adhered to epithelial villi in the jejunum and ileum. However, the villi did not exhibit significant structural damage. Cultured bacteria were identified as E. hirae using the VITEK 2 system and polymerase chain reaction (PCR). Using PCR, we also confirmed that viruses and protozoa that can potentially infect piglet intestines were absent. In antibiotic susceptibility test, the bacteria were resistant to most types of antibiotics. This study presents rare cases of E. hirae infection of the piglet small intestine, which can occur in association with diarrhea possibly by the continuous use of antibiotics.

본 연구는 P. aeruginosa와 E. hirae을 대상으로 orthophenylphenol 20%를 함유한 훈증소독제, Fumagari OPP®의 살균효과를 평가하기 위해 수행되었다. 예비 시험에서, P. aeruginosa와 E. hirae의 현탁액 균수는 각각 2.8 × 108 와 3.6 × 108CFU/mL이었으며, 모든 훈증소독제에 노출시킨 담체의 균수는 모두 평판배지법과 여과법으로 배양한 시험균주 현탁액의 균수의 50%보다 많았다. 또한, 대조 담체로부터 회복된 P. aeruginosa와 E. hirae 균수는 각각 2.9 × 106와 2.7 × 106CFU/mL이었다. 훈증소독제의 살균효과 시험에서는, 훈증소독제를 처리한 담체의 P. aeruginosa 와 E. hirae의 감소 균수는 각각 6.46와 5.19 logCFU/mL 로 나타났다. 이상의 결과로부터, 훈증소독제, Fumagari OPP®는 P. aeruginosa와 E. hirae에 대해 효과적인 살균력 을 갖는 것으로 확인되었으며, 병원성 세균에 오염된 식품재료 및 주방용품의 소독에 적용할 수 있을 것으로 사료된다.

This test was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 20% ortho-phenylphenol against Pseudomonas aeruginosa (P. aeruginosa) and Enterococcus hirae (E. hirae). In preliminary tests, P. aeruginosa and E. hirae working culture suspension number (N value) were 2.8 × 108 and 4.0 × 108CFU/mL, respectively. And all the colony numbers on the carriers exposed to the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of P. aeruginosa and E. hirae recovered on the control-carriers (T value) was 2.8 × 108 and 3.4 × 106 CFU/mL, respectively. In the bactericidal effect of the fumigant, the reduction number of 2.8 × 108 (d value) was 6.46 and 5.19 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results from this study, the fumigation disinfectant containing 20% ortho-phenylphenol has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with the pathogenic bacteria.