Molecular Characterization of Salmonella spp. Isolates from Wild Colombian Babilla (Caiman crocodilus fuscus) Isolated In Situ. - Related Documents




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299401.0000Molecular Characterization of Salmonella spp. Isolates from Wild Colombian Babilla (Caiman crocodilus fuscus) Isolated In Situ. Salmonella enterica is a pathogen capable of colonizing various environments, including the intestinal tract of different animals such as mammals, birds, and reptiles, which can act as carriers. S. enterica infection induces different clinical diseases, gastroenteritis being the most common, which in some cases, can evolve to septicemia and meningitis. Reptiles and amphibians have been reported as a reservoir of Salmonella, and transmission of the pathogen to humans has been documented. This study aimed to determine the presence of virulence genes and characterize the genotypic antibiotic resistance profile in Salmonella strains isolated from Caiman crocodilus fuscus obtained in situ (natural habitat) in Prado, Tolima, Colombia in a previous study and stored in a strain bank in our laboratory. Fifteen Salmonella strains were evaluated through endpoint PCR to determine the presence of resistance genes and virulence genes. The genes bla(TEM), strB, and sul1 were detected in all the strains that confer resistance to ampicillin, streptomycin, and sulfamethoxazole, as well as the virulence genes invA, pefA, prgH, spaN, tolC, sipB, sitC, pagC, msgA, spiA, sopB, sifA, lpfA, csgA, hilA, orgA, iroN, avrA, and sivH, indicating the possible role of babilla (Caiman crocodilus fuscus) as a carrier of multidrug-resistant bacteria.202236496880
559410.9986Antibiotic resistance among fecal indicator bacteria from healthy individually owned and kennel dogs. Escherichia coli and Enterococcus faecalis strains isolated from anal swabs of clinically healthy dogs were examined for the presence of acquired antimicrobial resistance. The strains originated from dogs of 92 different owners and from eight breeding kennels. The purpose of the present study was to evaluate the resistance situation in the intestinal flora of the dog to assess the possible role of the dog flora as a reservoir of antimicrobial resistance. Multiple resistance was rarely found in E. coli strains collected from individually owned dogs, in contrast with strains from kennel dogs. Resistance to ampicillin, trimethoprim, and sulfamethoxazole was significantly less prevalent in E. coli from privately owned dogs than in strains from kennel dogs. Resistance rates against tetracycline and macrolides were unexpectedly high in E. faecalis strains. Two and three E. faecalis strains from individually owned dogs and kennel dogs, respectively, were resistant to gentamicin, an antibiotic often used for treating enterococcal infections in humans. This study demonstrates that resistance percentages may fluctuate with the choice of dog population. The observed antimicrobial resistance percentages indicate that the flora of healthy dogs may act as a reservoir of resistance genes.200415140396
550320.9986Molecular characterization of multi-drug resistant coagulase negative cocci in non-hospital environment. Antibiotic resistance crisis occasioned by sporadic appearance of multi-drug resistance (MDR) in human pathogens to clinically applied antimicrobials is a serious threat to global health. In this study, we investigated the drug resistant phenotype of Gram-positive cocci isolates from environment. Staphylococcus capitis and Staphylococcus haemolyticus colonies were isolated on mannitol-salt agar plates supplemented with tetracycline. Antibiotic susceptibility profile of the isolates via minimum inhibitory concentration (MIC) determination was examined. Isolates showed decreased sensitivity to clinically applied antimicrobial agents: tetracycline, kanamycin, erythromycin, norfloxacin, teicoplanin, and ampicillin. Genomic analysis demonstrated the presence of multiple antibiotic resistant genes in these bacteria, suggesting the origin of the multiple antimicrobials resistant phenotype. Tetracycline resistance of these isolates was transduced to Staphylococcus aureus-RN4220 strain. These findings indicate the presence of multiple antimicrobials resistant S. capitis and S. haemolyticus strain in a non-hospital setting. Moreover, the presence of plethora of genes responsible for MDR suggest that these strains could present potential threat to human health by serving as reservoir for lateral transference of antimicrobial resistance conferring foreign genetic elements to other clinically relevant pathogens.201931231110
563030.9986Preliminary Results on the Prevalence of Salmonella spp. in Marine Animals Stranded in Sicilian Coasts: Antibiotic Susceptibility Profile and ARGs Detection in the Isolated Strains. The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (bla(TEM), bla(OXA), tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.202134451393
559340.9986Acquired antimicrobial resistance in the intestinal microbiota of diverse cat populations. The aim of this study was to investigate the prevalence of acquired antimicrobial resistance in the resident intestinal microbiota of cats and to identify significant differences between various cat populations. Escherichia coli, Enterococcus faecalis, E. faecium and Streptococcus canis were isolated as faecal indicator bacteria from rectal swabs of 47 individually owned cats, 47 cattery cats and 18 hospitalised cats, and submitted through antimicrobial sensitivity tests. The results revealed that bacteria isolated from hospitalised and/or cattery cats were more frequently resistant than those from individually owned cats. E. coli isolates from hospitalised cats were particularly resistant to ampicillin, tetracycline and sulfonamide. Both enterococci and streptococci showed high resistance to tetracycline and in somewhat lesser extent to erythromycin and tylosin. Most E. faecium isolates were resistant to lincomycin and penicillin. One E. faecalis as well as one E. faecium isolate from hospitalised cats showed 'high-level resistance' (MIC > 500 microg/ml) against gentamicin, a commonly used antimicrobial agent in case of human enterococcal infections. The results of this research demonstrate that the extent of acquired antimicrobial resistance in the intestinal microbiota of cats depends on the social environment of the investigated population. It is obvious that the flora of healthy cats may act as a reservoir of resistance genes.200616330058
590750.9986Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products. Commercial starter culture bacteria are widely used in the production of dairy products and could represent a potential source for spread of genes encoding resistance to antimicrobial agents. To learn more about the antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products, a total of 189 isolates of lactic acid bacteria were examined for susceptibility to ampicillin, penicillin G, cephalothin, vancomycin, bacitracin, gentamicin, streptomycin, erythromycin, tetracycline, chloramphenicol, quinupristin/dalfopristin, ciprofloxacin, trimethoprim and sulphadiazine using Etest for MIC determination. Most of the isolates (140) originated from 39 dairy products (yoghurt, sour cream, fermented milk and cheese), while 49 were isolated directly from nine commercial cultures. The bacteria belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Streptococcus. Only one of the 189 isolates was classified as resistant to an antimicrobial agent included in the study. This isolate, a lactobacillus, was classified as high level resistant to streptomycin. The remaining isolates were not classified as resistant to the antimicrobial agents included other than to those they are known to have a natural reduced susceptibility to. Thus, starter culture bacteria in Norwegian dairy products do not seem to represent a source for spread of genes encoding resistance to antimicrobial agents.200111482563
590160.9985Identification and characterization of vancomycin-resistant Enterococcus species frequently isolated from laboratory mice. To determine the prevalence of drug resistant bacteria colonizing laboratory mice, we isolated and characterized vancomycin-resistant Enterococcus species (VRE) from commercially available mice. A total of 24 VRE isolates were obtained from 19 of 21 mouse strains supplied by 4 commercial breeding companies. Of these, 19 isolates of E. gallinarum and 5 isolates of E. casseliflavus possessing the vanC1 and vanC2/3 genes intrinsically, exhibited intermediate resistance to vancomycin respectively. In addition, these isolates also exhibited diverse resistant patterns to erythromycin, tetracycline, and ciprofloxacin, whereas the use of antibiotics had not been undertaken in mouse strains tested in this study. Although 6 virulence-associated genes (ace, asa, cylA, efaA, esp, and gelE) and secretion of gelatinase and hemolysin were not detected in all isolates, 23 of 24 isolates including the isolates of E. casselifalvus secreted ATP into culture supernatants. Since secretion of ATP by bacteria resident in the intestinal tract modulates the local immune responses, the prevalence of ATP-secreting VRE in mice therefore needs to be considered in animal experiments that alter the gut microflora by use of antibiotics.201425077759
550070.9985Whole genome sequence analyses-based assessment of virulence potential and antimicrobial susceptibilities and resistance of Enterococcus faecium strains isolated from commercial swine and cattle probiotic products. Enterococcus faecium is one of the more commonly used bacterial species as a probiotic in animals. The organism, a common inhabitant of the gut of animals and humans, is a major nosocomial pathogen responsible for a variety infections in humans and sporadic infections in animals. In swine and cattle, E. faecium-based probiotic products are used for growth promotion and gut functional and health benefits. The objective of this study was to utilize whole genome sequence-based analysis to assess virulence potential, detect antimicrobial resistance genes, and analyze phylogenetic relationships of E. faecium strains from commercial swine and cattle probiotics. Genomic DNA extracted from E. faecium strains, isolated from commercial probiotic products of swine (n = 9) and cattle (n = 13), were sequenced in an Illumina MiSeq platform and analyzed. Seven of the nine swine strains and seven of the 13 cattle strains were identified as Enterococcus lactis, and not as E. faecium. None of the 22 probiotic strains carried major virulence genes required to initiate infections, but many carried genes involved in adhesion to host cells, which may benefit the probiotic strains to colonize and persist in the gut. Strains also carried genes encoding resistance to a few medically important antibiotics, which included aminoglycosides [aac(6')-Ii, aph(3')-III, ant(6)-Ia], macrolide, lincosamide and streptogramin B (msrC), tetracyclines [tet(L) and tet(M)], and phenicols [cat-(pc194)]. The comparison of the genotypic to phentypic AMR data showed presence of both related and unrelated genes in the probiotic strains. Swine and cattle probiotic E. faecium strains belonged to diverse sequence types. Phylogenetic analysis of the probiotic strains, and strains of human (n = 29), swine (n = 4), and cattle (n = 4) origin, downloaded from GenBank, indicated close clustering of strains belonging to the same species and source, but a few swine and cattle probiotic strains clustered closely with other cattle and human fecal strains. In conclusion, the absence of major virulence genes characteristic of the clinical E. faecium strains suggests that these probiotic strains are unlikely to initiate opportunistic infection. However, the carriage of AMR genes to medically important antibiotics and close clustering of the probiotic strains with other human and cattle fecal strains suggests that probiotic strains may pose risk to serve as a source of transmitting AMR genes to other gut bacteria.202235150575
239480.9985Occurrence of antimicrobial resistance and virulence genes, and distribution of enterococcal clonal complex 17 from animals and human beings in Korea. Enterococci are major zoonotic bacteria that cause opportunistic infections in human beings and animals. Moreover, pathogenic strains can be disseminated between human beings and animals, particularly companion animals that come into frequent contact with people. Recently, Enterococcus faecium clonal complex 17 (CC17) has emerged as a pandemic clone. Most CC17 strains are ampicillin resistant and possess virulence genes such as esp and hyl. Despite the possible dissemination of CC17 between human beings and animals, prevalence data about CC17 in animals is limited. In the present study, the phenotypes and genotypes of antimicrobial resistance were compared, as well as virulence gene profiles from 184 enterococci strains isolated from chickens, pigs, companion animals, and human patients in Korea. Ampicillin-resistant E. faecium (AREF) strains were selected, and multilocus sequence typing was performed to investigate the dispersion of CC17 among animals and human beings. The companion animal and human isolates showed high resistance rates to ampicillin and ciprofloxacin, whereas food animal isolates showed high tetracycline and erythromycin resistance rates. Ampicillin-resistant E. faecium was only detected in human (21/21 E. faecium, 100%) and companion animal (3/5 E. faecium, 60%) isolates, and all human AREF strains and 1 canine AREF strain were confirmed as CC17. In conclusion, the occurrence of antimicrobial resistance and virulence genes, and the distribution of enterococcal CC17 in companion animal enterococcal strains were similar to those of human strains rather than to those of food animal strains.201222855376
590690.9985Antibiotic resistance of probiotic strains of lactic acid bacteria isolated from marketed foods and drugs. OBJECTIVE: To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probiotics. METHODS: Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR. RESULTS: Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis. CONCLUSION: Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.200920163065
5532100.9985Alarming Antibiotic Resistance of Lactobacilli Isolated from Probiotic Preparations and Dietary Supplements. In this study, we screened eight commercially available brands of Lactobacillus-containing probiotic preparations and dietary supplements for resistance towards commonly administered antibiotics of different classes. According to disc diffusion results, most of the isolates were resistant to vancomycin and susceptible to penicillin-type antibiotics (ampicillin and amoxicillin), carbapenems (imipenem, meropenem, and ertapenem), and inhibitors of protein synthesis (chloramphenicol, erythromycin, tetracycline, clarithromycin, and linezolid). However, based on minimum inhibitory concentration (MIC) values, six strains were reconsidered as resistant to tetracycline. All tested lactobacilli were resistant towards amikacin, ciprofloxacin, and norfloxacin. Resistance to cephalosporins was highly variable and decreased in the following order: ceftazidime/cefepime, ceftriaxone, cefotaxime, cefazolin, and cefoperazone. PCR screening for antibiotic resistance determinants in probiotic lactobacilli revealed a wide occurrence of vancomycin resistance gene vanX, ciprofloxacin resistance gene parC, and extended-spectrum β-lactamase gene blaTEM. We also detected the tetK gene for tetracycline resistance in one isolate. Additionally, we identified discrepancies between the claims of the manufacturers and the identified species composition, as well as the enumerated amount of viable bacteria, for several products. The results of this study raise concerns about the safety of lactobacilli for human consumption as probiotics, as they may act as reservoirs of transferable antibiotic resistance genes.202236358212
5496110.9985Genome-Wide Analysis of Escherichia coli Isolated from Dairy Animals Identifies Virulence Factors and Genes Enriched in Multidrug-Resistant Strains. The gastrointestinal tracts of dairy calves and cows are reservoirs of antimicrobial-resistant bacteria (ARB), which are present regardless of previous antimicrobial therapy. Young calves harbor a greater abundance of resistant bacteria than older cows, but the factors driving this high abundance are unknown. Here, we aimed to fully characterize the genomes of multidrug-resistant (MDR) and antimicrobial-susceptible Escherichia coli strains isolated from pre-weaned calves, post-weaned calves, dry cows, and lactating cows and to identify the accessory genes that are associated with the MDR genotype to discover genetic targets that can be exploited to mitigate antimicrobial resistance in dairy farms. Results indicated that both susceptible and resistant E. coli isolates recovered from animals on commercial dairy operations were highly diverse and encoded a large pool of virulence factors. In total, 838 transferrable antimicrobial resistance genes (ARGs) were detected, with genes conferring resistance to aminoglycosides being the most common. Multiple sequence types (STs) associated with mild to severe human gastrointestinal and extraintestinal infections were identified. A Fisher's Exact Test identified 619 genes (ARGs and non-ARGs) that were significantly enriched in MDR isolates and 147 genes that were significantly enriched in susceptible isolates. Significantly enriched genes in MDR isolates included the iron scavenging aerobactin synthesis and receptor genes (iucABCD-iutA) and the sitABCD system, as well as the P fimbriae pap genes, myo-inositol catabolism (iolABCDEG-iatA), and ascorbate transport genes (ulaABC). The results of this study demonstrate a highly diverse population of E. coli in commercial dairy operations, some of which encode virulence genes responsible for severe human infections and resistance to antibiotics of human health significance. Further, the enriched accessory genes in MDR isolates (aerobactin, sit, P fimbriae, and myo-inositol catabolism and ascorbate transport genes) represent potential targets for reducing colonization of antimicrobial-resistant bacteria in the calf gut.202337887260
5904120.9985Antimicrobial susceptibilities of Lactobacillus, Pediococcus and Lactococcus human isolates and cultures intended for probiotic or nutritional use. OBJECTIVES: To determine MICs of 16 antimicrobials representing all major classes for 473 taxonomically well-characterized isolates of lactic acid bacteria (LAB) encompassing the genera Lactobacillus, Pediococcus and Lactococcus. To propose tentative epidemiological cut-off (ECOFF) values for recognizing intrinsic and acquired antimicrobial resistances in numerically dominant species. METHODS: On the basis of depositors' information, LAB were grouped in categories of probiotic, nutritional, probiotic or nutritional research, human and animal isolates and tested for their antibiotic susceptibilities by broth microdilution using LAB susceptibility test medium (LSM). Tentative ECOFFs were defined according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing. Isolates showing acquired antimicrobial resistance(s) were selected for PCR-based detection of resistance gene(s) and in vitro conjugative transfer experiments. RESULTS: Tentative ECOFF values of 13 antibiotics were determined for up to 12 LAB species. Generally, LAB were susceptible to penicillin, ampicillin, ampicillin/sulbactam, quinupristin/dalfopristin, chloramphenicol and linezolid. LAB exhibited broad or partly species-dependent MIC profiles of trimethoprim, trimethoprim/sulfamethoxazole, vancomycin, teicoplanin and fusidic acid. Three probiotic Lactobacillus strains were highly resistant to streptomycin. Although erythromycin, clindamycin and oxytetracycline possessed high antimicrobial activities, 17 Lactobacillus isolates were resistant to one or more of these antibiotics. Eight of them, including six probiotic and nutritional cultures, possessed erm(B) and/or tet(W), tet(M) or unidentified members of the tet(M) group. In vitro intra- and interspecies filter-mating experiments failed to show transfer of resistance determinants. CONCLUSIONS: Finding of acquired resistance genes in isolates intended for probiotic or nutritional use highlights the importance of antimicrobial susceptibility testing in documenting the safety of commercial LAB.200717369278
2885130.9985Antimicrobial susceptibility of Streptococcus gallolyticus isolated from humans and animals. Susceptibilities to some antimicrobial agents and distribution of genes associated with resistance were examined in a total of 66 Streptococcus gallolyticus isolates and reference strains from various sources. All the tested bacteria were susceptible to vancomycin, penicillin G, and ampicillin. Most of the erythromycin-resistant isolates were observed in human clinical samples. Tetracycline and doxycycline resistance was prevalent in the isolates from human patients, diseased animals, and healthy broiler chickens, while the prevalence was significantly lower in the isolates from healthy mammals. All the isolates resistant to tetracycline possessed tet(M) and/or tet(L) and/or tet(O) genes. However, most isolates from healthy animals, which were susceptible to tetracycline, possessed the above-cited resistance genes, implying the potential ability for resistance under exposure to the corresponding antimicrobial agents.201323883848
5900140.9985Safety profiles of beneficial lactic acid bacteria isolated from dairy systems. This study aimed to assess the safety aspects of 15 lactic acid bacteria (LAB) strains previously isolated from a dairy environment with relation to their beneficial features. LAB strains were assessed using phenotypic methods according to their production of virulence factors at 25 °C and 37 °C, as well as by examining their potential resistance to 15 antibiotics. Polymerase chain reaction (PCR) was also used to identify the presence of 50 genes associated with virulence factors and antibiotic resistance in the strains. None of the strains presented hemolytic activity or the production of gelatinase, lipase, deoxyribonuclease, or the tested biogenic amines. Based on the disk diffusion assay, all strains were resistant to oxacillin and sulfa/trimethoprim. Further, some were resistant to gentamicin (14), clindamycin (11), vancomycin (9), rifampicin (8), erythromycin (5), tetracycline (4), ampicillin (2), and chloramphenicol (1); no strain was resistant to imipenem. Regarding virulence- and antibiotic-resistance-related genes, 19 out of 50 tested genes were present in some strains; there was a variable association of expression. Based on the obtained data, the isolates presented relatively safe characteristics and behavior, findings that should lead to further studies to assess their potential usage as beneficial cultures in the food industry.202031970700
5529150.9985Vancomycin and florfenicol resistant Enterococcus faecalis and Enterococcus faecium isolated from human urine in an Egyptian urban-rural community. Multidrug resistance is one of the top three threats to global public health. Understanding resistance of bacteria is important to help decrease resistance and improve the development of novel antimicrobial agents or other alternative tools to combat public health challenges. Thus, the goal of this study was to investigate the vancomycin and florfenicol resistance genes of five E. faecalis and 15 E. faecium isolated from patients with urinary tract infections. There were 20 Enterococcus obtained from the library collection of randomly selected private hospitals located in the city of El Qanater El Khayreya; these samples were isolated during 2017. Samples were evaluated for their phenotypic characterization of virulence factors, antimicrobial resistance and PCR was conducted to detect the prescence of the vancomycin vanABC and florfenicol resistance genes encoding the catAB, fexAB and cfu. There were six different antibiotic resistance profiles observed. The 20 isolates showed resistance to clindamycin, oxytetracycline and gentamycin. Resistance was evident to ciprofloxacin, norfloxacin and florfenicol in the absence of the cfr gene in all of the 20 Enterococcus isolates. In addition, all isolates produced biofilms and were classified as extensive drug resistant. MAR(indices) of the isolates were >0.6. The MAR(index) of human isolates of enterococci suggest these pathogens originate from a high-risk source of contamination where antibiotics are often used. This information highlights a possible public health concern to the Egyptian community. The results also suggest the emergence of a linezolid sensitive-vancomycin resistant E. faecium and E. faecalis in the absence of the cfr gene.202031600524
3657160.9985A survey of antibiotic resistance in Micrococcaceae isolated from Italian dry fermented sausages. The transfer of bacteria that are resistant to antimicrobial agents or resistance genes from animals to humans via the food chain is increasingly a problem. Therefore, it is important to determine the species and the numbers of bacteria involved in this phenomenon. For this purpose, 148 strains of microstaphylococci were isolated from three types of Italian dry fermented sausages. Eight of 148 strains belonged to the genera Kocuria and Micrococcus. The remaining 140 strains belonged to 11 different species of the genus Staphylococcus. The species most frequently isolated was Staphylococcus xylosus, followed by Staphylococcus saprophyticus and Staphylococcus aureus. Antibiotic resistance levels differed among the species and depended on the strain origin. Microstaphylococci were generally susceptible to beta-lactams, but 12 strains were resistant to methicillin, 8 were resistant to oxacillin, and 9 were resistant to penicillin G. No resistance was observed for aminoglicosides and cephalosporines. Many strains were resistant to sulfonamide, colistin suphate, tetracyclin, and bacitracin. Two strains of S. aureus, four strains of S. xylosus, and one strain of Staphylococcus sciuri were able to grow in the presence of 8 microg of vancomycin per g, but all strains were susceptible to teicoplanin. Twenty-two microstaphylococci were resistant to at least five of the tested antibiotics. The multiresistant strain S. aureus 899 was unaffected by eight antibiotics, including vancomycin and methicillin, indicating that a more prudent use of antibiotics in animal husbandry and better hygienic conditions during production should be encouraged because they can play a major role in reducing the incidence of such multiresistant microorganisms and the possible spread of the genetic elements of their resistance.200312800992
5736170.9985Comparative Genomic Analysis and Antimicrobial Resistance Profile of Enterococcus Strains Isolated from Raw Sheep Milk. The role of Enterococcus spp. in food is debated since this group of lactic acid bacteria contains opportunistic pathogenic strains, some of which exhibit a multidrug-resistant profile. In livestock farms, the use of antibiotics is the most common practice to deal with mastitis-causing bacteria. However, the heavy usage and/or misuse of antibiotics has led to the emergence of antibiotic resistance. This study aimed to genetically and phenotypically characterize Enterococcus strains isolated from raw sheep milk. Samples were collected over one year from the bulk tank of a dairy sheep farm and cultured on selective media. Isolates were purified and analyzed by whole-genome sequencing and antimicrobial susceptibility testing. The isolates were divided into clusters and the corresponding species were identified along with their genes related to virulence and antibiotic resistance. The pan-, core- and accessory-genomes of the strains were determined. Finally, the antibiotic-resistant profile of selected strains was examined and associated with their genomic characterization. These findings contribute to a better understanding of Enterococci epidemiology, providing comprehensive profiles of their virulence and resistance genes. The presence of antibiotic-resistant bacteria in raw sheep milk destined for the production of cheese should raise awareness.202540872636
2884180.9985Gilthead seabream (Sparus aurata) carrying antibiotic resistant enterococci. A potential bioindicator of marine contamination? Antibiotic resistance in bacteria is a growing problem that is not only restricted to the clinical setting but also to other environments such as marine species that harbor antibiotic resistant bacteria and therefore may serve as reservoirs for antibiotic-resistance genetic determinants. The aim of this study was to evaluate antibiotic resistance phenotypes in enterococci isolated from fecal samples of gilthead seabream and the associated mechanisms of resistance. A collection of 118 samples were analyzed and 73 enterococci were recovered. The strains showed high percentages of resistance to erythromycin and tetracycline (58.9% and 17.8%, respectively). Lower level of resistance (<13%) was detected for quinupristin-dalfopristin, ampicillin, high-level-gentamicin, high-level-streptomycin, high-level-kanamycin, ciprofloxacin and chloramphenicol. The erm(B), tet(L) or tet(M), aac(6')-aph(2″) and aph(3')-IIIa genes were shown in isolates resistant to erythromycin, tetracycline, high-level gentamicin and high-level kanamycin, respectively. Antibiotic resistance in natural microbiota is becoming a concern of human and environmental health.201121511306
5735190.9985A Comprehensive Virulence and Resistance Characteristics of Listeria monocytogenes Isolated from Fish and the Fish Industry Environment. Listeria monocytogenes is an important pathogen, often associated with fish, that can adapt and survive in products and food processing plants, where it can persist for many years. It is a species characterized by diverse genotypic and phenotypic characteristics. Therefore, in this study, a total of 17 L. monocytogenes strains from fish and fish-processing environments in Poland were characterized for their relatedness, virulence profiles, and resistance genes. The Core Genome Multilocus Sequence Typing (cgMLST) analysis revealed that the most frequent serogroups were IIa and IIb; sequence types (ST) were ST6 and ST121; and clonal complexes (CC) were CC6 and CC121. Core genome multilocus sequence typing (cgMLST) analysis was applied to compare the present isolates with the publicly available genomes of L. monocytogenes strains recovered in Europe from humans with listeriosis. Despite differential genotypic subtypes, most strains had similar antimicrobial resistance profiles; however, some of genes were located on mobile genetic elements that could be transferred to commensal or pathogenic bacteria. The results of this study showed that molecular clones of tested strains were characteristic for L. monocytogenes isolated from similar sources. Nevertheless, it is worth emphasizing that they could present a major public health risk due to their close relation with strains isolated from human listeriosis.202336834997