Antimicrobial Resistance Profile and Genotypic Characteristics ofStreptococcus suisCapsular Type 2 Isolated from Clinical Carrier Sows and Diseased Pigs in China

Abstract

Streptococcus suis serotype 2 is an important zoonotic pathogen. Antimicrobial resistance phenotypes and genotypic characterizations of S. suis 2 from carrier sows and diseased pigs remain largely unknown. In this study, 96 swine S. suis type 2, 62 from healthy sows and 34 from diseased pigs, were analyzed. High frequency of tetracycline resistance was observed, followed by sulfonamides. The lowest resistance of S. suis 2 for β-lactams supports their use as the primary antibiotics to treat the infection of serotype 2. In contrast, 35 of 37 S. suis 2 with MLSB phenotypes were isolated from healthy sows, mostly encoded by the ermB and/or the mefA genes. Significantly lower frequency of mrp+/epf+/sly+ was observed among serotype 2 from healthy sows compared to those from diseased pigs. Furthermore, isolates from diseased pigs showed more homogeneously genetic patterns, with most of them clustered in pulsotypes A and E. The data indicate the genetic complexity of S. suis 2 between herds and a close linkage among isolates from healthy sows and diseased pigs. Moreover, many factors, such as extensive use of tetracycline or diffusion of Tn916 with tetM, might have favored for the pathogenicity and widespread dissemination of S. suis serotype 2.

Streptococcus suis in Brazil: Genotypic, Virulence, and Resistance Profiling of Strains Isolated from Pigs between 2001 and 2016

“…Regarding antimicrobial resistance profiling, the high resistance rates to tetracyclines, macrolides, clindamycin, and sulfamethoxazole detected in the present study appear to be common in S. suis in recent years, since they are present in several studies carried out in different geographic areas [8,10,29]. In addition, a very low rate of β-lactams resistance was observed among the Brazilian S. suis strains, regardless of their origin.…”

Prevalence of multiple drug resistant Streptococcus suis in and around Guwahati, India

“…A proportionately higher susceptibility to β -lactams and aminoglycosides were also reported previously [5,11,17,22]. On the contrary, high levels of resistance to these agents were also reported by various workers [9,19,23-25]. …”

Güney Çin’de Hastalıklı ve Sağlıklı Domuzlarda Streptococcus suis’in Antimikrobiyal Direnci, Serotipleri ve Genetik Çeşitliliği

“…Previous reports suggested that S. suis strains had a high resistance to macrolides, lincosamides, tetracycline, and sulfonamides [11][12][13][14][15] . The S. suis isolates in this study showed a high resistance to macrolides, lincosamides, tetracycline, and sulfonamides, as well as a high resistance to quinolones and aminoglycosides.…”

“…Previous reports suggested the resistance rate for β-lactams in S. suis was low [11,14,36] . In this study, the resistance rate of other β-lactams was relatively low except for cefixime, which indicates that β-lactams may be the primary drugs to treat the infection of S. suis.…”

“…Antimicrobial agents play an important role in the treatment and control of S. suis infection. However, irrational use of antibiotics leads to a continual increase in drug resistance of S. suis worldwide [11][12][13][14][15] . Therefore, antimicrobial susceptibility testing is a crucial step preceding the prescription of antibiotic treatment.…”