Trends in the serovar and antimicrobial resistance in clinical isolates of Salmonella enterica from cattle and pigs between 2002 and 2016 in Japan

Abstract

Aims Given the significance of Salmonella enterica in both human and animal health, and a recent global dissemination of Salmonella 4,[5],12:i:‐, changes in the prevalent serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs were investigated in Japan. Methods and Results The serovars and antimicrobial susceptibilities of 1605 Salmonella enterica isolated from cattle (n = 894) and swine (n = 711) between 2002 and 2016 were examined. The most common serovar among all samples was Salmonella Typhimurium. However, its monophasic variant with antigenic structure S. 4,[5],12:i:‐, which was first detected in cattle in 2006 and swine in 2010, has been rapidly increasing in incidence and resistance. Resistance rates to cefotaxime and ciprofloxacin were generally low (<10% in the cattle isolates and <5% in the swine isolates); however, isolates resistant to more than five antimicrobials, which often include these antimicrobials, were recently detected in Salmonella Dublin, S. 4,[5],12:i:‐, S. Typhimurium, Salmonella Newport, Salmonella Choleraesuis and Salmonella 6,7:c:‐. Among them, two S. 4,[5],12:i:‐ isolates possessed extended‐spectrum β‐lactamase‐encoding genes; blaSHV‐12 or blaCTX‐M‐55, respectively, while all the five S. Typhimurium isolates possessed AmpC‐type β‐lactamase gene of blaCMY‐2. Conclusions S. 4,[5],12:i:‐ has been rapidly increasing and exhibiting a remarkable change in antimicrobial resistance in Japan. Considering certain serovars are characterized by multidrug resistance including medically important antimicrobials, continuous monitoring and appropriate measures are required to protect public health and veterinary husbandry. Significance and Impact of the Study This study presents a trend in the serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs in Japan, and showed that there were certain types of Salmonella serovars depending on the animal origin which needs more attention.

Molecular Characterization of Cephalosporin-Resistant Salmonella Enteritidis ST11 Isolates Carrying blaCTX-M from Children with Diarrhea

“…Despite a number of studies regarding the prevalence and dissemination of cephalosporin resistance in Salmonella from adults and animals, limited information concerning cephalosporin resistance for infections of children is available (Chao et al, 2017;Ma et al, 2018;Feng et al, 2019;Kijima et al, 2019). In our study, we collected Salmonella Enteritidis isolates from children younger than 5 years in China to identify their cephalosporin resistance levels and to determine the transferability of bla CTX-M .…”

IsSalmonella entericashared between wildlife and cattle in cattle farming areas? An 11‐year retrospective study in Tokachi district, Hokkaido, Japan

“…Dublin was detected from wildlife in the vicinity of S. Dublin epidemics in cattle as in this study, which implied that S. Dublin seemed to be transmitted from cattle to wildlife (Glawischnig et al, 2017;Jones & Twigg, 1976). A monophasic variant of S. Typhimurium, S. 4,[5],12:i:-, has been increasingly reported as the causative agent of salmonellosis in livestock and humans around the world, including Japan (EFSA, 2018;Kijima et al, 2019;Soyer et al, 2009). Previous studies suggested that a certain epidemic clone was dominant in recent S. 4,[5],12:i:-isolates in Europe and Japan (Arai et al, 2018;Petrovska et al, 2016).…”

“…The genetically similar S. Typhimurium strains were shared between wildlife and cattle, but not detected in the same year. S. Typhimurium is a common serotype in both wildlife and cattle (Kijima et al, 2019Simpson et al, 2018Tizard, 2004). Considering the year of detection of isolates in each species for clade IDs 3 and 5, to which both wildlife and cattle isolates belong (Figure 7), cattle strains were possibly transmitted to wildlife and then maintained in the population.…”

“…Typhimurium, S . 4,[5],12:i:‐, has been increasingly reported as the causative agent of salmonellosis in livestock and humans around the world, including Japan (EFSA, 2018 ; Kijima et al., 2019 ; Soyer et al., 2009 ). Previous studies suggested that a certain epidemic clone was dominant in recent S .…”

Antimicrobial Resistance in Salmonella Isolated from Food Workers and Chicken Products in Japan

“…Typhimurium, its monophasic variant, and S . Newport are prevalent in local cattle and pigs [ 15 ], beef and pork may represent sources of Salmonella infections among food workers.…”