■猪链球菌是猪和人的主要病原体。在这里,我们旨在了解2016年至2021年间在西班牙回收的侵袭性猪链球菌分离株的抗菌素耐药性(AMR)率,并阐明其遗传起源。
■对不同遗传背景和地理来源的116株分离株进行了抗生素敏感性试验,对9个家族的18种抗生素进行了敏感性试验。使用Pearson卡方检验和似然比对AMR与基因型之间的关联以及分离株的来源进行统计学分析。通过全基因组测序分析和PCR筛选鉴定抗菌素抗性基因。
■检测到四环素的高AMR率(>80%),壮观霉素,lincosamides,和马波沙星,磺胺类/甲氧苄啶的培养基(20-40%),tiamulin,青霉素G,和恩诺沙星,氟苯尼考含量低(<20%),和四种额外的β-内酰胺。在90%的分离株中观察到多药耐药性的发生。对于某些抗生素(青霉素G,恩诺沙星,马波沙星,替米考星,和红霉素),AMR与特定序列类型(STs)显着相关,地理区域,猪的年龄和时间进程。全基因组测序比较和PCR筛选确定了23个AMR基因,其中19项先前在S.suis(aph(3')-IIIa,sat4,aade,spw,aac(6\')-Ie-aph(2\'\')-Ia,FexA,optrA,erm(B),MEF(A/E),夫人(D),mph(C),lnu(B),lsa(E),vga(F),tet(M),tet(O),tet(O/W/32/O),tet(W)),和4个是新颖的(aph(2\'\')-IIIa,apmA,erm(47),tet(T))。这些AMR基因将AMR解释为壮观霉素,大环内酯类,lincosamides,tiamulin,还有四环素.几个基因位于显示可变组织和组成的可移动遗传元件上。由于在许多人和动物病原体中鉴定出AMR基因同源物,猪链球菌的抗性组具有不同的系统发育起源。此外,AMR到青霉素G,氟喹诺酮类药物,和与编码目标酶的基因突变相关的甲氧苄啶(pbp1a,pbp2b,PBP2x,mray,gyra,ParC,和dhfr)。生物信息学分析估计的目标基因重组性状,也表明基因转移事件。
■我们的工作证明猪链球菌是AMR在兽医和人类病原体中传播的主要贡献者。因此,猪链球菌AMR的控制应考虑从一个健康的方法在高猪生产的地区,以适当地解决抗菌药物耐药性的问题。
Streptococcus suis is a major pathogen for swine and human. Here we aimed to know the rates of antimicrobial resistance (AMR) in invasive S. suis isolates recovered along Spain between 2016 - 2021 and elucidate their genetic origin.
Antibiotic susceptibility testing was performed for 116 isolates of different genetic backgrounds and geographic origins against 18 antibiotics of 9 families. The association between AMR and genotypes and the origin of the isolates were statistically analyzed using Pearson´s chi-square test and the likelihood ratio. The antimicrobial resistant genes were identified by whole genome sequencing analysis and PCR screenings.
High AMR rates (>80%) were detected for tetracyclines, spectinomycin, lincosamides, and marbofloxacin, medium (20-40%) for sulphonamides/trimethoprim, tiamulin, penicillin G, and enrofloxacin, and low (< 20%) for florfenicol, and four additional β-lactams. The occurrence of multidrug resistance was observed in 90% of isolates. For certain antibiotics (penicillin G, enrofloxacin, marbofloxacin, tilmicosin, and erythromycin), AMR was significantly associated with particular sequence types (STs), geographic regions, age of pigs, and time course. Whole genome sequencing comparisons and PCR screenings identified 23 AMR genes, of which 19 were previously reported in S. suis (aph(3\')-IIIa, sat4, aadE, spw, aac(6\')-Ie-aph(2\'\')-Ia, fexA, optrA, erm(B), mef(A/E), mrs(D), mph(C), lnu(B), lsa(E), vga(F), tet(M), tet(O), tet(O/W/32/O), tet(W)), and 4 were novel (aph(2\'\')-IIIa, apmA, erm(47), tet(T)). These AMR genes explained the AMR to spectinomycin, macrolides, lincosamides, tiamulin, and tetracyclines. Several genes were located on mobile genetic elements which showed a variable organization and composition. As AMR gene homologs were identified in many human and animal pathogens, the resistome of S. suis has a different phylogenetic origin. Moreover, AMR to penicillin G, fluoroquinolones, and trimethoprim related to mutations in genes coding for target enzymes (pbp1a, pbp2b, pbp2x, mraY, gyrA, parC, and dhfr). Bioinformatic analysis estimated traits of recombination on target genes, also indicative of gene transfer events.
Our work evidences that S. suis is a major contributor to AMR dissemination across veterinary and human pathogens. Therefore, control of AMR in S. suis should be considered from a One Health approach in regions with high pig production to properly tackle the issue of antimicrobial drug resistance.