Detection of clinically relevant antimicrobial resistance determinants in warm-blooded marine animals in Livingston Island (South Shetland Islands, Antarctica): A field-based molecular genetics study. - Related Documents




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366901.0000Detection of clinically relevant antimicrobial resistance determinants in warm-blooded marine animals in Livingston Island (South Shetland Islands, Antarctica): A field-based molecular genetics study. Molecular genetic studies of stools were performed to assess the spread of some clinically relevant antimicrobial resistance determinants (ARD) in a gentoo penguin (Pygoscelis papua) and an Antarctic fur seal (Arctocephalus gazella) on Livingston Island. Glycopeptide resistance genes (vanA/vanD and vanB) were detected in both fecal samples, while the penguin's one was also mecA-positive and bla(NDM)-positive. Because of the remoteness and the isolation of the sampling locations, the carriage of vancomycin-resistant Enterococcus spp., methicillin-resistant Staphylococcus aureus, and NDM-producing Enterobacterales or other gram-negative bacilli suggested an ocean pollution with antibiotic resistant bacteria (ARB). Additionally, due to the type of ARD we detected, our results are alarming, and they cannot be explained only with agricultural and/or aquacultural pollution. Even though the current study is a preliminary one, it also demonstrates the potential of the field genetics analyses carried out with minimal equipment as a reliable monitoring tool for pollution with ARB.202235597002
550210.9991Short communication: Diversity of species and transmission of antimicrobial resistance among Staphylococcus spp. isolated from goat milk. The increasing production of goat milk and its derivatives is affected by the occurrence of intramammary infections, which are highly associated with the presence of Staphylococcus species, including some with zoonotic potential. Staphylococci in general can exchange mobile genetic elements, a process that may be facilitated by the isolate's capacity of forming biofilms. In this study we identified, to the species level, Staphylococcus isolated from goat milk samples by MALDI-TOF and confirmed the identification by sequencing housekeeping genes (rrs and tuf). Eight species were identified, more than half being either Staphylococcus epidermidis or Staphylococcus lugdunensis. The isolates were shown by pulsed-field gel electrophoresis to be genetically diverse between the studied herds. Resistance to ampicillin and penicillin was widespread, and 2 Staph. epidermidis isolates contained the methicillin-resistance gene mecA. Most of the isolates that were resistant to at least 1 of the 13 antimicrobials tested harbored plasmids, one of which was demonstrated to be conjugative, being transferred from a Staph. epidermidis to a Staphylococcus aureus strain. Biofilm formation was observed in almost every isolate, which may contribute to their capacity of exchanging antimicrobial resistance genes in addition to acting as a physical barrier to the access of drugs. Our results showed that antimicrobial resistance among goat staphylococci may be emerging in a process facilitated by the exchange of mobile genetic elements between the bacteria and the establishment of biofilms, which calls for careful monitoring and more effective control therapies.201930928272
459720.9991Antimicrobial-resistant enterococci in animals and meat: a human health hazard? Enterococcus faecium and Enterococcus faecalis belong to the gastrointestinal flora of humans and animals. Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The use of avoparcin, gentamicin, and virginiamycin for growth promotion and therapy in food animals has lead to the emergence of vancomycin- and gentamicin-resistant enterococci and quinupristin/dalfopristin-resistant E. faecium in animals and meat. This implies a potential risk for transfer of resistance genes or resistant bacteria from food animals to humans. The genes encoding resistance to vancomycin, gentamicin, and quinupristin/dalfopristin have been found in E. faecium of human and animal origin; meanwhile, certain clones of E. faecium are found more frequently in samples from human patients, while other clones predominate in certain animal species. This may suggest that antimicrobial-resistant E. faecium from animals could be regarded less hazardous to humans; however, due to their excellent ability to acquire and transfer resistance genes, E. faecium of animal origin may act as donors of antimicrobial resistance genes for other more virulent enterococci. For E. faecalis, the situation appears different, as similar clones of, for example, vancomycin- and gentamicin-resistant E. faecalis have been obtained from animals and from human patients. Continuous surveillance of antimicrobial resistance in enterococci from humans and animals is essential to follow trends and detect emerging resistance.201020578915
583230.9991New quadriplex PCR assay for detection of methicillin and mupirocin resistance and simultaneous discrimination of Staphylococcus aureus from coagulase-negative staphylococci. Major challenges in diagnostic molecular microbiology are to develop a simple assay to distinguish Staphylococcus aureus from the less virulent but clinically important coagulase-negative staphylococci (CoNS) and to simultaneously determine their antibiotic resistance profiles. Multiplex PCR assays have been developed for the detection of methicillin- and mupirocin-resistant S. aureus and CoNS but not for the simultaneous discrimination of S. aureus from CoNS. We designed a new set of Staphylococcus genus-specific primers and developed a novel quadriplex PCR assay targeting the 16S rRNA (Staphylococcus genus specific), nuc (S. aureus species specific), mecA (a determinant of methicillin resistance), and mupA (a determinant of mupirocin resistance) genes to identify most staphylococci, to discriminate S. aureus from CoNS and other bacteria, and to simultaneously detect methicillin and mupirocin resistance. Validation of the assay with 96 ATCC control strains and 323 previously characterized clinical isolates, including methicillin- and mupirocin-sensitive and -resistant S. aureus and CoNS isolates and other bacteria, demonstrated 100% sensitivity, specificity, and accuracy. This assay represents a simple, rapid, accurate, and reliable approach for the detection of methicillin- and mupirocin-resistant staphylococci and offers the hope of preventing their widespread dissemination through early and reliable detection.200415528678
556440.9991Epidemiology of the colonization and acquisition of methicillin-resistant staphylococci and vancomycin-resistant enterococci in dogs hospitalized in a clinic veterinary hospital in Spain. Antibiotic resistance is one of the biggest threats to human and animal health. Methicillin-resistant Staphylococcus spp. (MRS) and vancomycin-resistant Enterococcus spp. (VRE) are of increasing importance in hospital and/or nosocomial infections and represent a potential risk of transmission to humans from infected or colonized companion animals. Studies on the risk factors associated with colonization by multiresistant bacteria in animals are scarce. The present study aimed to estimate the prevalence and incidence of MRS and VRE in canine patients hospitalized in a veterinary hospital and to identify the risk factors for its acquisition and persistence. Nasal and perianal swabs were obtained from 72 dogs. Antimicrobial susceptibility assays and molecular detection of mecA and van genes were performed. A prevalence of 13.9% and incidence of 26.5% was observed in dogs colonized by MRS at hospital admission and release, respectively, higher values than those described in most veterinary studies. Thirty-five Staphylococcus isolates had mecA gene and showed higher resistance levels to most of the antimicrobials evaluated. Previous and concomitant use of antibiotics and corticosteroids has been associated with an increase in MRS colonization. The use of antibiotics in other animals living with the canine patients has also been identified as an associated factor, suggesting cross transmission. The presence of van-resistant genes from Enterococcus spp. was not detected. Pets should be considered possible vehicles of transmission and reservoirs for MRS bacteria and veterinary hospitals should be considered high-risk environments for the occurrence and spread of nosocomial infections and resistant bacteria.202032535110
459850.9991Enterococci of animal origin and their significance for public health. Enterococci are commensal bacteria in the intestines of humans and animals, but also cause infections in humans. Most often, Enterococcus faecium isolates from clinical outbreaks belong to different types than E. faecium from animals, food, and humans in the community. The same variants of the vanA gene cluster (Tn1546) encoding vancomycin resistance can be detected in enterococci of both human and animal origin. This could indicate horizontal transfer of Tn1546 between enterococci of different origin. E. faecium isolates of animal origin might not constitute a human hazard in themselves, but they could act as donors of antimicrobial resistance genes for other pathogenic enterococci. Enterococcus faecalis of animal origin seems to be a human hazard, as the same types can be detected in E. faecalis from animals, meat, faecal samples from humans in the community, and patients with bloodstream infections.201222487203
570760.9991Comparative genomics of vancomycin-resistant Enterococcus spp. revealed common resistome determinants from hospital wastewater to aquatic environments. The rise of vancomycin-resistant Enterococcus spp. (VRE) has led to treatment challenges in hospital settings worldwide. Hospital wastewater (HW) might disseminate this threat to the aquatic environment. Thus, this study elucidates the VRE resistance quotient (RQ) of different environmental matrixes in wastewater and compares genomic determinants of VRE strains recovered from HW to water resources. Presumptive Enterococcus spp. and VRE were quantified and isolated using standard microbiological procedures. Fourteen VRE genomes were then sequenced using an Illumina HiSeq X™ Ten platform. Subsequently, VRE genomes were compared based on antibiotic resistance genes, plasmids, bacteriophages, insertion sequences, transposons, virulence and pathogenicity. Wastewater effluent showed the highest RQ among all sampled matrixes. The phylogeny of vancomycin-resistant E. faecalis (VREfs) and E. faecium (VREfm) revealed a tree structure based on their respective sequence type. A comparative genomic analysis of 14 genomes highlighted regions encoding phage protein, phage holin, phage integrase, integrase and transposase on both query genomes and the reference genome. Acquired resistance to vancomycin was conferred by vanA, vanN, vanL, vanG and the intrinsic resistance vanC operons. Plasmids were dominated by the presence of conserved areas of the replication initiating genes (rep). The Tn3-like and Tn917 transposons were present in all erythromycin-carrying erm(B) isolated VRE genomes. All VRE genomes expect one were putatively predicted as human pathogens with varying degrees of virulence. The presence of such resistant bacteria in African water resource is of great public health concern. It is, therefore, recommended that these bacteria be tracked and characterised from different environments to contribute to improved epidemiological containment action.202032109727
547770.9991An in-house 45-plex array for the detection of antimicrobial resistance genes in Gram-positive bacteria. Identifying antimicrobial resistance (AMR) genes and determining their occurrence in Gram-positive bacteria provide useful data to understand how resistance can be acquired and maintained in these bacteria. We describe an in-house bead array targeting AMR genes of Gram-positive bacteria and allowing their rapid detection all at once at a reduced cost. A total of 41 AMR probes were designed to target genes frequently associated with resistance to tetracycline, macrolides, lincosamides, streptogramins, pleuromutilins, phenicols, glycopeptides, aminoglycosides, diaminopyrimidines, oxazolidinones and particularly shared among Enterococcus and Staphylococcus spp. A collection of 124 enterococci and 62 staphylococci isolated from healthy livestock animals through the official Belgian AMR monitoring (2018-2020) was studied with this array from which a subsample was further investigated by whole-genome sequencing. The array detected AMR genes associated with phenotypic resistance for 93.0% and 89.2% of the individual resistant phenotypes in enterococci and staphylococci, respectively. Although linezolid is not used in veterinary medicine, linezolid-resistant isolates were detected. These were characterized by the presence of optrA and poxtA, providing cross-resistance to other antibiotics. Rarer, vancomycin resistance was conferred by the vanA or by the vanL cluster. Numerous resistance genes circulating among Enterococcus and Staphylococcus spp. were detected by this array allowing rapid screening of a large strain collection at an affordable cost. Our data stress the importance of interpreting AMR with caution and the complementarity of both phenotyping and genotyping methods. This array is now available to assess other One-Health AMR reservoirs.202336825880
597480.9991Use of a bacterial antimicrobial resistance gene microarray for the identification of resistant Staphylococcus aureus. As diagnostic and surveillance activities are vital to determine measures needed to control antimicrobial resistance (AMR), new and rapid laboratory methods are necessary to facilitate this important effort. DNA microarray technology allows the detection of a large number of genes in a single reaction. This technology is simple, specific and high-throughput. We have developed a bacterial antimicrobial resistance gene DNA microarray that will allow rapid antimicrobial resistance gene screening for all Gram-positive and Gram-negative bacteria. A prototype microarray was designed using a 70-mer based oligonucleotide set targeting AMR genes of Gram-negative and Gram-positive bacteria. In the present version, the microarray consists of 182 oligonucleotides corresponding to 166 different acquired AMR gene targets, covering most of the resistance genes found in both Gram-negative and -positive bacteria. A test study was performed on a collection of Staphylococcus aureus isolates from milk samples from dairy farms in Québec, Canada. The reproducibility of the hybridizations was determined, and the microarray results were compared with those obtained by phenotypic resistance tests (either MIC or Kirby-Bauer). The microarray genotyping demonstrated a correlation between penicillin, tetracycline and erythromycin resistance phenotypes with the corresponding acquired resistance genes. The hybridizations showed that the 38 antimicrobial resistant S. aureus isolates possessed at least one AMR gene.201021083822
596890.9991A PCR assay for rapid detection of vancomycin-resistant enterococci. Since the first report of a vancomycin-resistant enterococcal clinical isolate, these Gram-positive bacteria have emerged as important nosocomial pathogens. Several glycopeptide resistance phenotypes can be distinguished on the basis of the level and inducibility of resistance to vancomycin and teicoplanin. In the present study, we developed a multiplex PCR, which allows the simultaneous identification of enterococci at the genus level and detection of the most frequent glycopeptide resistance genotypes. Five primer sets targeting the genes vanA, vanB, vanC1, vanC2/C3 and tuf were used in one reaction tube with bacterial DNA extracted from three to five colonies. This PCR method is suitable for the rapid detection of vancomycin-resistant enterococci.200212007446
5566100.9991Resistance to antimicrobial agents used for animal therapy in pathogenic-, zoonotic- and indicator bacteria isolated from different food animals in Denmark: a baseline study for the Danish Integrated Antimicrobial Resistance Monitoring Programme (DANMAP). This study describes the establishment and first results of a continuous surveillance system of antimicrobial resistance among bacteria isolated from pigs, cattle and broilers in Denmark. The three categories of bacteria tested were: 1) indicator bacteria (Escherichia coli, Enterococcus faecalis, Enterococcus faecium), 2) zoonotic bacteria (Campylobacter coli/jejuni, Salmonella enterica, Yersinia enterocolitica), and 3) animal pathogens (E. coli, Staphylococcus aureus, coagulase-negative staphylococci (CNS), Staphylococcus hyicus, Actinobacillus pleuropneumoniae). A total of 3304 bacterial isolates collected from October 1995 through December 1996 were tested for susceptibility to all major classes of antimicrobial agents used for therapy in Denmark. Bacterial species intrinsically resistant to an antimicrobial were not tested towards that antimicrobial. Acquired resistance to all antimicrobials was found. The occurrence of resistance varied by animal origin and bacterial species. In general, resistance was observed more frequently among isolates from pigs than from cattle and broilers. The association between the occurrence of resistance and the consumption of the antimicrobial is discussed, as is the occurrence of resistance in other countries. The results of this study show the present level of resistance to antimicrobial agents among a number of bacterial species isolated from food animals in Denmark. Thus, the baseline for comparison with future prospective studies has been established, enabling the determination of trends over time.19989744762
2551110.9991Characterization of vancomycin-resistance vanD gene clusters in the human intestinal microbiota by metagenomics and culture-enriched metagenomics. OBJECTIVES: To characterize vancomycin-resistance vanD gene clusters and potential vanD-carrying bacteria in the intestinal microbiota of healthy volunteers exposed or not to β-lactam antibiotics. METHODS: Stool samples were collected before and after 7 days of cefprozil β-lactam antibiotic exposure of 18 participants and six control participants who were not exposed to the antibiotic at the same time points. Metagenomic sequencing and culture-enriched metagenomic sequencing (with and without β-lactam selection) were used to characterize vanD gene clusters and determine potential vanD-carrying bacteria. Alteration by antimicrobials was also examined. RESULTS: Culture enrichment allowed detection of vanD genes in a large number of participants (11/24; 46%) compared to direct metagenomics (2/24; 8%). vanD genes were detected in stool cultures only following β-lactam exposure, either after β-lactam treatment of participants or after culture of stools with β-lactam selection. Six types of vanD gene clusters were identified. Two types of vanD cluster highly similar to those of enterococci were found in two participants. Other vanD genes or vanD clusters were nearly identical to those identified in commensal anaerobic bacteria of the families Lachnospiraceae and Oscillospiraceae and/or bordered by genomic sequences similar or related to these anaerobes, suggesting that they are the origin or carriers of vanD. CONCLUSIONS: This study showed that culture-enriched metagenomics allowed detection of vanD genes not detected by direct metagenomics and revealed collateral enrichment of bacteria containing vancomycin-resistance vanD genes following exposure to β-lactams, with a higher prevalence of the most likely gut commensal anaerobes carrying vanD. These commensal anaerobes could be the reservoir of vanD genes carried by enterococci.202336968950
4752120.9990Antibiotic resistance in gram-positive bacteria: epidemiological aspects. The emergence and spread of antibiotic resistance in gram-positive bacterial pathogens has become an increasing problem. There has been a dramatic increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci and enterococci. This is mainly due to the clonal dissemination of certain epidemic multiply-resistant strains, for example, those of MRSA and S. pneumoniae, as well as to the spread of resistance genes as exemplified by those causing glycopeptide resistance in enterococci.199910511391
3410130.9990vanA Gene Harboring Enterococcal and Non-enterococcal Isolates Expressing High Level Vancomycin and Teicoplanin Resistance Reservoired in Surface Waters. Untreated wastewaters and treated effluents even after final disinfection contain antibiotic resistant bacteria and resistance genes before they are released into surface waters. A correlation between resistant bacteria and antibiotics in surface waters has been found, as have antibiotic resistance genes. Of particular interest are vancomycin-resistant enterococci harboring vanA gene that confers high level of resistance to glycopeptide antibiotics including teicoplanin. Therefore, in this study, river water samples were analysed to investigate vancomycin- and teicoplanin-resistant bacterial isolates harboring vanA gene. Out of 290, 15 surface water isolates displayed resistance to both antibiotics. These glycopeptide resistant enterococcal and non-enterococcal isolates, identified by 16S rRNA sequencing, were found to harbor vanA gene with sequence similarities of 50 % to 100 %. The presence of D-alanine-D-lactate ligase encoded by vanA gene was also shown for all vancomycin- and teicoplanin-resistant isolates through western blot analysis. Due to reuse of treated wastewater and release of untreated wastewaters to water bodies, antibiotic resistant bacteria and resistance genes are being introduced into surface waters and present human health risks. Therefore, surface waters are not only hot spots for vanA harboring enterococcal isolates but also non-enterococcal isolates due to gene dissemination and require special scientific consideration.201727770152
3951140.9990Diversity and genetic lineages of environmental staphylococci: a surface water overview. Antimicrobial resistance in the environmental dimension is one of the greatest challenges and emerging threats. The presence of resistant bacteria and resistance genes in the environment, especially in aquatic systems, has been a matter of growing concern in the past decade. Monitoring the presence of antimicrobial resistance species, in this particular case, Staphylococcus spp., in natural water environments could lead to a better understanding of the epidemiology of staphylococci infections. Thus, the investigation of natural waters as a potential reservoir and vehicle for transmission of these bacteria is imperative. Only a few studies have investigated the prevalence, antimicrobial resistance and genetic lineages of staphylococci in natural waters. Those studies reported a high diversity of staphylococci species and lineages in surface waters. Methicillin-resistant S. aureus were relatively prevalent in surface waters and, as expected, often presented a multidrug-resistant profile. There was a high diversity of S. aureus lineages in surface waters. The presence of S. aureus CC8 and CC5 suggests a human origin. Among the coagulase-negative staphylococci, the most frequently found in natural waters was S. warneri and S. epidermidis. These studies are extremely important to estimate the contribution of the aquatic environment in the spread of pathogenic bacteria.202032949464
3667150.9990An Overview on Streptococcus bovis/Streptococcus equinus Complex Isolates: Identification to the Species/Subspecies Level and Antibiotic Resistance. Streptococcus bovis/Streptococcus equinus complex (SBSEC), a non-enterococcal group D Streptococcus spp. complex, has been described as commensal bacteria in humans and animals, with a fecal carriage rate in humans varying from 5% to over 60%. Among streptococci, SBSEC isolates represent the most antibiotic-resistant species-with variable resistance rates reported for clindamycin, erythromycin, tetracycline, and levofloxacin-and might act as a reservoir of multiple acquired genes. Moreover, reduced susceptibility to penicillin and vancomycin associated with mobile genetic elements have also been detected, although rarely. Since the association of SBSEC bacteremia and colon lesions, infective endocarditis and hepatobiliary diseases has been established, particularly in elderly individuals, an accurate identification of SBSEC isolates to the species and subspecies level, as well as the evaluation of antibiotic resistance, are needed. In this paper, we reviewed the major methods used to identify SBSEC isolates and the antimicrobial resistance rates reported in the scientific literature among SBSEC species.201930678042
5676160.9990Fosfomycin Resistance in Bacteria Isolated from Companion Animals (Dogs and Cats). Fosfomycin is an old antibacterial agent, which is currently used mainly in human medicine, in uncomplicated Urinary Tract Infections (UTIs). The purpose of this review is to investigate the presence and the characteristics of Fosfomycin resistance in bacteria isolated from canine or feline samples, estimate the possible causes of the dissemination of associated strains in pets, and underline the requirements of prospective relevant studies. Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines were used for the search of current literature in two databases. A total of 33 articles were finally included in the review. Relevant data were tracked down, assembled, and compared. Referring to the geographical distribution, Northeast Asia was the main area of origin of the studies. E. coli was the predominant species detected, followed by other Enterobacteriaceae, Staphylococci, and Pseudomonas spp. FosA and fosA3 were the more frequently encountered Antimicrobial Resistance Genes (ARGs) in the related Gram-negative isolates, while fosB was regularly encountered in Gram-positive ones. The majority of the strains were multidrug-resistant (MDR) and co-carried resistance genes against several classes of antibiotics and especially β-Lactams, such as bla(CTX-M) and mecA. These results demonstrate the fact that the cause of the spreading of Fosfomycin-resistant bacteria among pets could be the extended use of other antibacterial agents, that promote the prevalence of MDR, epidemic strains among an animal population. Through the circulation of these strains into a community, a public health issue could arise. Further research is essential though, for the comprehensive consideration of the issue, as the current data are limited.202337235420
4936170.9990A New Tool for Analyses of Whole Genome Sequences Reveals Dissemination of Specific Strains of Vancomycin-Resistant Enterococcus faecium in a Hospital. A new easy-to-use online bioinformatic tool analyzing whole genome sequences of healthcare associated bacteria was used by a local infection control unit to retrospectively map genetic relationship of isolates of E. faecium carrying resistance genes to vancomycin in a hospital. Three clusters of isolates were detected over a period of 5 years, suggesting transmission between patients. Individual relatedness between isolates within each cluster was established by SNP analyses provided by the system. Genetic antimicrobial resistance mechanisms to antibiotics other than vancomycin were identified. The results suggest that the system is suited for hospital surveillance of E. faecium carrying resistance genes to vancomycin in settings with access to next Generation Sequencing without bioinformatic expertise for interpretation of the genome sequences.202134778297
5988180.9990Enterococcal vanB resistance locus in anaerobic bacteria in human faeces. While developing a rapid method to detect carriers of vancomycin-resistant enterococci (VRE), we found the vanB gene by PCR in 13 of 50 human faecal specimens that did not contain culturable VRE. Passaging under antibiotic selection allowed us to isolate two species of anaerobic bacteria that were vanB PCR positive, vancomycin resistant, and teicoplanin sensitive. Sequence analysis of the 16S rRNA genes showed that one isolate resembled Eggerthella lenta (98% identity), and the other Clostridium innocuum (92% identity). Southern hybridisation and nucleotide sequencing showed a vanB locus homologous to that in VRE. We propose that vanB resistance in enterococci might arise from gene transfer in the human bowel.200111265957
4592190.9990The Genetic Diversity and Antimicrobial Resistance of Pyogenic Pathogens Isolated from Porcine Lymph Nodes. According to the Food and Agriculture Organization of the United Nations, pork remains the most consumed meat in the world. Consequently, it is very important to ensure that it is of the highest microbiological quality. Many of the pathogens that cause lymph node lesions in pigs are zoonotic agents, and the most commonly isolated bacteria are Mycobacterium spp., Streptococcus spp., Staphylococcus aureus and Rhodococcus equi (synonymous with Prescottella equi). The prevention and treatment of zoonotic infections caused by these bacteria are mainly based on antimicrobials. However, an overuse of antimicrobials contributes to the emergence and high prevalence of antimicrobial-resistant strains, which are becoming a serious challenge in many countries. The aim of this study was to evaluate the genetic diversity and antimicrobial resistance of the Streptococcus spp. (n = 48), S. aureus (n = 5) and R. equi (n = 17) strains isolated from swine lymph nodes with and without lesions. All isolates of S. dysgalactiae, S. aureus and R. equi were subjected to PFGE analysis, which showed the genetic relatedness of the tested bacteria in the studied pig populations. Additionally, selected tetracycline and macrolide resistance genes in the streptococcal strains were also studied. The results obtained in the present study provide valuable data on the prevalence, diversity, and antimicrobial resistance of the studied bacteria. Numerous isolated bacterial Streptococcus spp. strains presented resistance to doxycycline, and almost half of them carried tetracycline resistance genes. In addition, R. equi and S. aureus bacteria presented a high level of resistance to beta-lactam antibiotics and to cefotaxime, respectively.202337370345