# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3067 | 0 | 1.0000 | An Insight into the Presence of Antimicrobial Resistance Genes in Opportunistic Pathogenic Bacteria Isolated from Farm-Reared Crickets. To support the role of insects as sustainable feed and food ingredients, evaluating their potential microbiological risk and safety is crucial. In this study, we investigated the presence of antimicrobial resistance (AMR) genes in selected live opportunistic pathogenic bacteria isolated during the rearing process from clinically healthy farm-reared crickets. Molecular analysis was performed by wholegenome sequencing of a total of 14 of these bacterial strains, 7 from house crickets (Acheta domesticus) and 7 from banded crickets (Gryllodes sigillatus), belonging to Enterobacteriaceae, Staphylococcaceae, Enterococcaceae, and Bacillaceae families. The β-lactam AMR genes (bla(OXY2-6), bla(ACT-16), and bla(SHV) variants) were the most predominant genes identified, mainly in Enterobacteriaceae strains and in association with fosfomycin (fosA) and oqxAB efflux pump complexes. In addition, blaZ and mecA genes were detected in Bacillus cereus and Mammaliicoccus sciuri strains isolated from both insect species. Genetic mobile elements including IncFIA, IncFIB, IncHI1A, IncHI1B, rep13, and Col3M-like plasmids were detected in Klebsiella pneumoniae, Enterobacter hormaechei, Staphylococcus arlettae, and B. cereus, respectively. The results indicate that, not only in the final product but also during the insect-rearing process, microbial safety control, regarding the presence of pathogenic bacteria and AMR genes, is essential for effectively decreasing the microbiological risk between cricket batches within their environment and in terms of the related feed and food chain. | 2025 | 40005757 |
| 2793 | 1 | 0.9995 | Investigating Antibiotic Resistance Genes in Marketed Ready-to-Eat Small Crickets (Acheta domesticus). The present investigation was aimed at evaluating the occurrence of transferable genes conferring resistance to tetracyclines, macrolide-lincosamide-streptogramin B (MLS(B) ), vancomycin, beta-lactams, and aminoglycosides in 32 samples from eight batches of ready-to-eat crickets (Acheta domesticus) commercialized by four European Union producers (two batches per producer). Bacterial DNA extracted directly from the insects was subjected to optimized polymerase chain reaction (PCR) and nested-PCR assays for the qualitative detection of 12 selected antibiotic resistance (AR) genes. Microbial enumeration demonstrated high counts of spore-forming bacteria and total mesophilic aerobes. Statistical analyses revealed significant differences between different producers and insect batches. Regarding AR genes, a high prevalence of genes conferring resistance to tetracycline [tet(M), tet(O), tet(K), tet(S)] was observed, together with the presence of genes conferring resistance to erythromycin [erm(B), erm(C)], beta-lactams (blaZ and mecA), and aminoglycosides [aac(6')-Ie aph(2")-Ia]. We performed a principal component analysis based on the AR gene frequencies that differentiated samples of batch 1 from those of batch 2. This analysis provided evidence for a difference between the producer from France and all the other producers among the batch 1 samples. PRACTICAL APPLICATION: Overall, an intrabatch variation was seen in the transferable resistances among different producers. This evidence, coupled with the observed differences in the viable counts, suggests a low standardization of the production processes. Hence, a prudent use of antimicrobials during the rearing of insects destined for human consumption is strongly recommended, as well as a need for a full standardization of production technologies. | 2019 | 31600843 |
| 2424 | 2 | 0.9992 | Antimicrobial-Resistance Genetic Markers in Potentially Pathogenic Gram Positive Cocci Isolated from Brazilian Soft Cheese. Although most Brazilian dairy products meet high technological standards, there are quality issues regarding milk production, which may reduce the final product quality. Several microbial species may contaminate milk during manufacture and handling. If antimicrobial usage remains uncontrolled in dairy cattle, the horizontal transfer of antimicrobial resistance genes in foodstuffs may be of particular concern for both food producers and dairy industry. This study focused on the evaluation of putative Gram positive cocci in Minas cheese and of antimicrobial and biocide resistance genes among the isolated bacteria. Representative samples of 7 different industrially trademarked Minas cheeses (n = 35) were processed for selective culture and isolation of Gram positive cocci. All isolated bacteria were identified by DNA sequencing of the 16S rRNA gene. Antimicrobial resistance genes were screened by PCR. Overall, 208 strains were isolated and identified as follows: Enterococcus faecalis (47.6%), Macrococcus caseolyticus (18.3%), Enterococcus faecium (11.5%), Enterococcus caseliflavus (7.7%), Staphylococcus haemolyticus (7.2%), Staphylococcus aureus (4.3%), Staphylococcus epidermidis (2.9%), and Enterococcus hirae (0.5%). The genetic markers mecA (78.0%) and smr (71.4%) were the most prevalent, but others were also detected, such as blaZ (65.2%), msrA (60.9%), msrB (46.6%), linA (54.7%), and aacA-aphD (47.6%). The occurrence of opportunist pathogenic bacteria harboring antimicrobial resistance markers in the cheese samples are of special concern, since these bacteria are not considered harmful contaminating agents according to the Brazilian sanitary regulations. However, they are potentially pathogenic bacteria and the cheese may be considered a reservoir for antimicrobial resistance genes available for horizontal transfer through the food chain, manufacturing personnel and consumers. | 2018 | 29337343 |
| 5581 | 3 | 0.9992 | Prevalence of pathogens harbouring mobile antimicrobial resistance genes and virulence factors in retail beef and mutton. Food safety is always a global issue, due to the increased dissemination of antimicrobial resistance and food poisoning related to foodborne bacterial pathogens. The purpose of this study was to assess the risk of potential foodborne bacteria of beef and mutton in retail stores. A total of 134 samples were collected from 24 local markets in Beijing, including raw and cooked beef or mutton, as well as samples derived from the corresponding environment and human beings. We obtained 674 isolates, of which Klebsiella spp. and Staphylococcus spp. were the dominant bacterial species in the meat samples and the environmental samples, respectively. Additionally, environmental bacteria are common in samples from different sources. Based on the results of antimicrobial sensitivity testing, resistance to tetracycline (with a resistance rate of 47.40%), amoxicillin + clavulanate (47.13%) and erythromycin (28.03%) were the major resistant phenotypes. According to the whole genome analysis, the extended spectrum beta-lactamase genes harboured by two K. pneumoniae strains isolated from cooked and raw beef were located on mobile elements. The major toxin genes of Bacillus cereus and adhesion- or invasion-related virulence factors were also shared among isolates from different sources. These factors pose potential risks to public health and need attention. | 2020 | 32510554 |
| 3119 | 4 | 0.9992 | Bacterial Communities Associated with Houseflies (Musca domestica L.) Inhabiting Hospices in South Africa. Houseflies are alleged reservoirs as well as vectors of human and animal pathogens, including bacteria, because they frequently have contact with animal excreta and decaying organic substances. The rapid adaptation process of ingested microbes in the insect gut may involve gene transfer, including antibiotic resistance determinants among different bacterial strains. Six hundred and fifty-seven (n = 657) houseflies were collected from hospices and were identified morphologically and genetically using the 16S rRNA, CO1, and ITS2 barcoding genes. This study also characterized the bacterial communities harboured by the captured houseflies using 16S rRNA metabarcoding on the next-generation sequencing (NGS) platform and further sought to detect antibiotic resistance traits by using gene-specific PCR assays. Generated sequences for the targeted gene fragments matched with Musca domestica and all the sequences were deposited to the GenBank database. The 16S rRNA metabarcoding analysis revealed that the most abundant phyla detected with variable abundance observed among all the houseflies were Proteobacteria, followed by Firmicutes, and Bacteroidetes. Furthermore, the NGS data revealed the presence of multiple bacterial genera, including Providencia, Enterobacter, Dysgonomonas, Escherichia-Shigella, Klebsiella, Pseudomonas, and Streptococcus, which are known to harbour potentially pathogenic species of animals and humans. Antibiotic resistance genes detected from the housefly DNA in this study included ermB, tetA, blaSHV, and blaTEM. Moreover, these genes are associated with resistance to erythromycin, tetracycline, and beta-lactams antibiotics, respectively. The presence of bacterial pathogens and the detection of antibiotic resistance genes from the houseflies collected from the hospices indicates the possible health risk to patients in hospices and the surrounding community. Therefore, it is imperative to keep high standards of hygiene, food preparation, safety, and control of houseflies in hospices. | 2023 | 37374941 |
| 5704 | 5 | 0.9992 | Bats as Hosts of Antimicrobial-Resistant Mammaliicoccus lentus and Staphylococcus epidermidis with Zoonotic Relevance. Bats are increasingly recognized as reservoirs for antimicrobial-resistant bacteria, playing a potential role in the dissemination of resistance genes across species and regions. In this study, 105 bats from 19 species in Portugal were sampled to investigate the presence, antimicrobial resistance, and genetic characteristics of Mammaliicoccus and Staphylococcus isolates. Thirteen Mammaliicoccus lentus and Staphylococcus epidermidis were recovered. Antimicrobial susceptibility testing revealed multidrug resistance in three isolates, with S. epidermidis carrying mph(C), msr(A), and dfrC genes, and M. lentus harboring salB, tet(K), and str. Notably, qacA was detected in S. epidermidis, highlighting its plasmid-associated potential for horizontal gene transfer to more pathogenic bacteria. Heavy metal resistance genes (arsB and cadD) were also identified, suggesting the role of environmental factors in co-selecting antimicrobial resistance. Molecular typing revealed the S. epidermidis strain as ST297, a clone associated with both healthy humans and invasive infections. These findings emphasize the need for monitoring bats as reservoirs of resistance determinants, particularly in the context of zoonotic and environmental health. The presence of mobile genetic elements and plasmids further underscores the potential for the dissemination of resistance. This study reinforces the importance of adopting a One Health approach to mitigate the risks associated with antimicrobial resistance. | 2025 | 40284824 |
| 5598 | 6 | 0.9992 | Antibiotic Resistance in Lactic Acid Bacteria from Dairy Products in Northern Italy. Background: The spread of antibiotic resistance genes (ARGs) from the food chain is a significant public health concern. Dairy products from raw milk containing lactic acid bacteria (LAB) resistant to antimicrobials may serve as vectors for the transfer of resistance to commensal or potentially pathogenic bacteria in the human gut. Detecting ARGs in dairy products and milk is, therefore, crucial and could aid in the development of strategies to mitigate resistance dissemination through the food chain. Objectives: This study aimed to determine the presence of ARGs and assess the antibiotic susceptibility of LAB strains isolated from dairy products made from raw milk. Methods: Fifty-four LAB strains were isolated from 41 dairy samples and were tested for antimicrobial susceptibility using broth microdilution to determine Minimal Inhibitory Concentration (MIC). Moreover, the presence of resistance genes related to tetracyclines, beta-lactams, quinolones, and erythromycin was examined using six multiplex PCR assays. Results: Lactobacillus spp. and Leuconostoc spp. strains exhibited a high level of resistance to vancomycin (93-100%). Low-level resistance (4.2-20%) was observed in Lactococcus spp. and Lactobacillus spp. strains against tetracycline. Additionally, Lactococcus spp. strains showed resistance to trimethoprim/sulfamethoxazole, erythromycin, and clindamycin. Twenty-two out of 54 LAB strains (40.7%) carried at least one antibiotic resistance gene, and five of these were multidrug-resistant. Genes associated with acquired resistance to tetracycline were commonly detected, with tetK being the most frequent determinant. Conclusions: This study demonstrated that LABs in dairy products can act as reservoirs for ARGs, potentially contributing to the horizontal transfer of resistance within microbial communities in food and consumers. These findings highlight the need for the ongoing surveillance of antibiotic resistance in LAB and the implementation of control measures to minimize the dissemination of resistance through dairy products. | 2025 | 40298519 |
| 2843 | 7 | 0.9992 | High Throughput Screening of Antimicrobial Resistance Genes in Gram-Negative Seafood Bacteria. From a global view of antimicrobial resistance over different sectors, seafood and the marine environment are often considered as potential reservoirs of antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs); however, there are few studies and sparse results on this sector. This study aims to provide new data and insights regarding the content of resistance markers in various seafood samples and sources, and therefore the potential exposure to humans in a global One Health approach. An innovative high throughput qPCR screening was developed and validated in order to simultaneously investigate the presence of 41 ARGs and 33 MGEs including plasmid replicons, integrons, and insertion sequences in Gram-negative bacteria. Analysis of 268 seafood isolates from the bacterial microflora of cod (n = 24), shellfish (n = 66), flat fishes (n = 53), shrimp (n = 10), and horse mackerel (n = 115) show the occurrence of sul-1, ant(3″)-Ia, aph(3')-Ia, strA, strB, dfrA1, qnrA, and bla(CTX-M-9) genes in Pseudomonas spp., Providencia spp., Klebsiella spp., Proteus spp., and Shewanella spp. isolates and the presence of MGEs in all bacterial species investigated. We found that the occurrence of MGE may be associated with the seafood type and the environmental, farming, and harvest conditions. Moreover, even if MGE were detected in half of the seafood isolates investigated, association with ARG was only identified for twelve isolates. The results corroborate the hypothesis that the incidence of antimicrobial-resistant bacteria (ARB) and ARG decreases with increasing distance from potential sources of fecal contamination. This unique and original high throughput micro-array designed for the screening of ARG and MGE in Gram-negative bacteria could be easily implementable for monitoring antimicrobial resistance gene markers in diverse contexts. | 2022 | 35744743 |
| 5597 | 8 | 0.9992 | Prevalence of macrolide-lincosamide-streptogramin resistant lactic acid bacteria isolated from food samples. Lactic acid bacteria (LAB) being a reservoir of antibiotic resistance genes, tend to disseminate antibiotic resistance that possibly pose a threat to human and animal health. Therefore, the study focuses on the prevalence of macrolide-lincosamide-streptogramin- (MLS) resistance among LAB isolated from various food samples. Diverse phenotypic and genotypic MLS resistance were determined among the LAB species (n = 146) isolated from fermented food products (n = 6) and intestine of food-producing animals (n = 4). Double disc, triple disc diffusion and standard minimum inhibitory concentration (MIC) tests were evaluated for phenotypic MLS resistance. Specific primers for MLS resistance genes were used for the evaluation of genotypic MLS resistance and gene expressions using total RNA of each isolate at different antibiotic concentrations. The isolates identified are Levilactobacillus brevis (n = 1), Enterococcus hirae (n = 1), Limosilactobacillus fermentum (n = 2), Pediococcus acidilactici (n = 3), Enterococcus faecalis (n = 1). The MIC tests along with induction studies displayed cMLS(b), L phenotype, M phenotype, KH phenotype, I phenotype resistance among MLS antibiotics. Genotypic evaluation tests revealed the presence of ermB, mefA/E, msrA/B and msrC genes. Also, gene expression studies displayed increased level of gene expression to the twofold increased antibiotic concentrations. In the view of global health concern, this study identified that food samples and food-producing animals represent source of antibiotic resistant LAB that can disseminate resistance through food chain. This suggests the implementation of awareness in the use of antibiotics as growth promoters and judicious use of antibiotics in veterinary sectors in order to prevent the spread of antibiotic resistance. | 2023 | 36712199 |
| 5595 | 9 | 0.9992 | Microbial Diversity and Resistome in Milk of Cows with Subclinical Mastitis in a Coastal District of Odisha, India. Mastitis is a globally prevalent bacterial disease of lactating cows. Prevention and control of this multi-etiological complex disease relies upon administration of antibiotics. This has led to the emergence of newer multi-drug resistant strains. In the current study, milk samples from subclinical mastitis cows and their healthy counterparts were subjected to Illumina-based whole genome metagenome sequencing to explore bacterial communities and antibiotic resistance genes associated with mastitis-affected and healthy udder. Bovine milk microbiome in subclinical mastitis-affected cows were dominated by pathogenic bacteria such as Acinetobacter baylyi, Acinetobacter pittii, Streptococcus agalactiae, Streptococcus suis, Streptococcus uberis, Aeromonas hydrophila, Aeromonas enteropelogenes, Lactococcus lactis, Corynebacterium resistens and Kocuria rhizophila. We observed higher bacterial abundance and diversity in milk of cows suffering from subclinical mastitis as compared to apparently healthy cows. Resistant genes against fluoroquinolones, peptides, β-lactams, tetracyclines and macrolides were detected in the subclinical group. In contrast, genes resistant to aminoglycosides, penams and β-lactams were found in healthy cow milk. The findings of the study expand our knowledge of bacterial diversity and associated resistant genes found in the milk of mastitis-affected and healthy cow milk. | 2024 | 39678985 |
| 5994 | 10 | 0.9992 | Characterization of Erythromycin and Tetracycline Resistance in Lactobacillus fermentum Strains. Lactobacillus fermentum colonizing gastrointestinal and urogenital tracts of humans and animals is widely used in manufacturing of fermented products and as probiotics. These bacteria may function as vehicles of antibiotic resistance genes, which can be transferred to pathogenic bacteria. Therefore, monitoring and control of transmissible antibiotic resistance determinants in these microorganisms is necessary to approve their safety status. The aim of this study was to characterize erythromycin and tetracycline resistance of L. fermentum isolates and to estimate the potential transfer of resistance genes from lactobacilli to the other Gram-positive and Gram-negative bacteria. Among six L. fermentum strains isolated from human feces and commercial dairy products, five strains demonstrated phenotypic resistance to tetracycline. PCR screening for antibiotic resistance determinants revealed plasmid-located tetracycline resistance genes tet(K) and tet(M) in all strains and erythromycin resistance genes erm(B) in the chromosome of L. fermentum 5-1 and erm(C) in the plasmid of L. fermentum 3-4. All tested lactobacilli lacked conjugative transposon Tn916 and were not able to transfer tetracycline resistance genes to Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Acinetobacter baumannii, Citrobacter freundii, and Escherichia coli by filter mating. Staphylococcus haemolyticus did not accept erythromycin resistance genes from corresponding Lactobacillus strains. Thus, in the present study, L. fermentum was not implicated in the spread of erythromycin and tetracycline resistance, but still these strains pose the threat to the environment and human health because they harbored erythromycin and tetracycline resistance genes in their plasmids and therefore should not be used in foods and probiotics. | 2018 | 30534155 |
| 5500 | 11 | 0.9992 | Whole 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. | 2022 | 35150575 |
| 2403 | 12 | 0.9992 | Characterization of coagulase-negative staphylococci and macrococci isolated from cheese in Germany. Cheese, especially ripened varieties, harbor a very complex and heterogeneous microbiota. In addition to the desired microorganisms (starter cultures) added during cheese production, potentially harmful bacteria may also enter the production chain. Regarding the latter, the focus of this study was on coagulase-negative staphylococci (CNS) and Macrococcuscaseolyticus. Both are known to harbor a variety of genes coding for antibiotic resistance, including mecA, mecB, mecC, and mecD. Coagulase-negative staphylococci or macrococci carrying such genes or other virulence factors should not be present in cheese. Cheese samples (101 in total) were collected from retail sources. Coagulase-negative staphylococci and M. caseolyticus were isolated utilizing selective agars, and species were identified by phenotypical tests and partial sequencing of the sodA gene. The results allowed identification of 53 CNS strains and 19 M. caseolyticus strains. Among the CNS, 11 isolates of Staphylococcus saprophyticus and one Staphylococcus epidermidis isolate were obtained. Both species are potential human pathogens and may thus adversely affect the safety of these food products. Screening for antimicrobial resistance was performed by application of disc diffusion tests, a gradient strip-test, and 14 different PCR tests. Evidence for methicillin resistance (by either positive disc diffusion assay for cefoxitin or by mec PCR) was found in CNS isolates and M. caseolyticus (9 isolates each). Regarding other virulence factors, no genetic determinants for coagulase or the most common staphylococcal enterotoxins sea, seb, sec, sed, and see were detected in any of the CNS or M. caseolyticus isolates by PCR testing. In conclusion, the presence of facultatively pathogenic CNS and carriers of genes for antibiotic resistance in both groups of microorganisms, especially mec genes, and the respective food safety issues need further evaluation and surveillance. | 2022 | 35965117 |
| 2818 | 13 | 0.9992 | Tetracycline resistance associated with commensal bacteria from representative ready-to-consume deli and restaurant foods. Proper knowledge of antibiotic resistance (AR) dissemination is essential for effective mitigation. This study examined the profiles of tetracycline-resistant (Tetr) commensal bacteria from representative ready-to-consume food samples from salad bars at local grocery stores and restaurants. Out of 900 Tetr isolates examined, 158 (17.6%) carried one or more of tetM, tetL, tetS, and tetK genes by conventional PCR, 28 harbored more than one Tetr determinants. The most prevalent genotype was tetM, which was detected in 70.9% of the AR gene carriers, followed by tetL (31.6%), tetS (13.9%), and tetK (2.5%). Identified AR gene carriers included Enterococcus, Lactococcus, Staphylococcus, Brochothrix, Carnobacterium, Stenotrophomonas, Pseudomonas, and Sphingobacterium, by 16S rRNA gene sequence analysis. AR determinants were successfully transmitted, and led to resistance in Streptococcus mutans via natural gene transformation and Enterococcus faecalis via electroporation, suggesting the functionality and mobility of the AR genes from the food commensal bacteria. In addition, the AR traits in many isolates are quite stable, even in the absence of the selective pressure. The identification of new commensal carriers for representative AR genes revealed the involvement of a broad spectrum of bacteria in the horizontal transmission of AR genes. Meanwhile, the spectrum of the antibiotic-resistant bacteria differed from the spectrum of the total bacteria (by denaturing gradient gel electrophoresis) associated with the food items. Our data revealed a common avenue in AR exposure and will assist in proper risk assessment and the development of comprehensive mitigation strategies to effectively combat AR. | 2010 | 21067672 |
| 5599 | 14 | 0.9991 | Antimicrobial susceptibility profiles of Staphylococcus spp. contaminating raw goat milk. BACKGROUND AND AIM: Antimicrobial resistance poses a major threat to global public health. Foodstuff of animal origin can serve as potential vehicles for the dissemination of antimicrobial-resistant bacteria and resistance genes to consumers. In view of the lack of knowledge about antimicrobial resistance in bacteria associated with goat milk, the aim of this study was to report species-level identification and antimicrobial susceptibility profiles of a large collection of Staphylococcus spp. isolates recovered from raw goat milk in Brazil. MATERIALS AND METHODS: A total of 434 Staphylococcus spp. isolates originated from 510 goat milk samples in Northeast Brazil were investigated. The isolates were obtained by conventional microbiological methods. Species identification and antimicrobial susceptibility testing were performed by means of a semi-automated system using a panel for biochemical tests and broth microdilution method for 19 antimicrobial drugs. RESULTS: Although Staphylococcus aureus (22.6%) accounted for the majority of the isolates, a total of 13 different non-aureus staphylococci spp. were identified. High resistance rates against erythromycin (40.8%), and the beta-lactams ampicillin (45.9%) and penicillin (42.9%) were observed among S. aureus isolates. The most significant findings were related to the resistance against quinupristin-dalfopristin, a drug of last resort used in human medicine to treat infections caused by vancomycin-resistant S. aureus and enterococci. CONCLUSION: The high diversity of Staphylococcus spp. showing phenotypic resistance against different antimicrobial drugs encourages further investigations on the real impact of these bacteria as reservoirs of antimicrobial resistance genes to consumers. Furthermore, the potential impact of technological processes, such as pasteurization, fermentation, and maturation, on the maintenance and dissemination of antimicrobial resistance among the microbial populations in milk and dairy products must also be investigated. | 2021 | 34220106 |
| 1929 | 15 | 0.9991 | Research Note: Detection of antibiotic-resistance genes in commercial poultry and turkey flocks from Italy. Antibiotics are routinely used in commercial poultry farms for the treatment of economically important bacterial diseases. Repeated use of antibiotics, usually administered in the feed or drinking water, may also result in the selection of resistant bacteria in animal feces, able to transfer their antimicrobial-resistance genes (ARG), residing on mobile elements, to other microorganisms, including human pathogens. In this study, single and multiplex PCR protocols were performed to detect tetracycline-, lincomycin-, chloramphenicol-, aminoglycoside-, colistin-, vancomycin-, and carbapenem-resistance genes, starting from 38 litter samples collected from 6 poultry and 2 turkey Italian flocks. The ARG were confirmed for all investigated classes of antimicrobials, except for colistin (mcr-1, mcr-2, mcr-3,mcr-4 mcr-5) and carbapenem (IMP, OXA-48, NDM, KPC), while the vanB gene was only detected for vancomycin. The highest positivity was obtained for tetracycline (tet[L], tet[M], tet[K], tetA[P]] and aminoglycoside (aadA2) ARG, confirming the predominant use of these antimicrobials in the veterinary practice and their potential to enhance the resistance patterns also in humans as a consequence of environmental contamination. On the contrary, the dissemination by poultry of ARG for critically important antimicrobials seems to be of minor concern, suggesting a negligible environmental dissemination by these genes in the Italian poultry industry. Finally, the molecular screening performed in this study using a noninvasive sampling method represents a simple and rapid tool for monitoring the ARG patterns at the farm level. | 2021 | 33799114 |
| 5646 | 16 | 0.9991 | Dispersion and persistence of antimicrobial resistance genes among Staphylococcus spp. and Mammaliicoccus spp. isolated along a swine manure treatment plant. Staphylococcus spp. and Mammaliicoccus spp. colonize the skin and mucosa of humans and other animals and are responsible for several opportunistic infections. Staphylococci antibiotic resistance may be present in the environment due to the spread of treated and untreated manure from the livestock industry due to antibiotic use to disease control or growth promoter. In this work, we analyzed the species distribution and antimicrobial susceptibility of Staphylococcus and Mammaliicoccus species along different sites of a swine manure treatment plant from Southeastern Brazil. Bacterial colonies were obtained on mannitol salt agar, selected after catalase test and Gram staining, and finally identified by mass spectrometry and sequencing of the tuf gene. According to the results, S.cohnii and S. simulans were the most prevalent species. Antibiotic resistance test revealed that several strains were resistant to multiple drugs, with high levels of chloramphenicol resistance (98%), followed by erythromycin (79%), tetracycline (73%), gentamicin (46%), ciprofloxacin (42%), cefoxitin (18%), sulfamethoxazole + trimethoprim (12%), and linezolid (4%). In addition, gene detection by PCR showed that all strains carried at least 2 resistance genes and one of them carried all 11 genes investigated. Using the GTG(5)-PCR approach, a high genetic similarity was observed between some strains that were isolated from different points of the treatment plant. Although some were seemingly identical, differences in their resistance phenotype and genotype suggest horizontal gene transfer. The presence of resistant bacteria and resistance genes along the treatment system highlights the potential risk of contamination by people in direct contact with these animals and the soil since the effluent is used as a biofertilizer in the surrounding environment. | 2023 | 36515883 |
| 1928 | 17 | 0.9991 | Targeted Antimicrobial Resistance Gene Screening from Metagenomic DNA of Raw Milk Samples Identifies the Presence of Multiple Genes Including the mcr9. The current study has investigated the prevalence of antimicrobial resistance (AMR) genes in cow and goat raw milk samples. The misuse of antibiotics in the livestock sector has already been reported to be a major factor contributing to AMR risk. For the study, milk samples were collected from five different farms, and metagenomic DNA was extracted. Then, PCR amplification was carried out using primers specific to 15 different AMR genes. From the results obtained, the prevalence of β-lactam resistance genes, particularly blaTEM (24%), along with other genes like blaZ (12%) and blaSHV (8%), were observed in addition to the transmissible mcr9 gene (12%) conferring resistance to colistin. These findings underscore the urgent need for monitoring AMR genes and regulating antibiotic use in dairy farming to safeguard public health, as it poses a potential risk with the consumption of unpasteurized milk. | 2025 | 40488653 |
| 5601 | 18 | 0.9991 | Presence of Staphylococcus spp. carriers of the mecA gene in the nasal cavity of piglets in the nursery phase. The presence of Staphylococcus spp. resistant to methicillin in the nasal cavity of swine has been previously reported. Considering the possible occurrence of bacterial resistance and presence of resistance genes in intensive swine breeding and the known transmissibility and dispersion potential of such genes, this study aimed to investigate the prevalence of resistance to different antibiotics and the presence of the mecA resistance gene in Staphylococcus spp. from piglets recently housed in a nursery. For this, 60 nasal swabs were collected from piglets at the time of their housing in the nursery, and then Staphylococcus spp. were isolated and identified in coagulase-positive (CoPS) and coagulase-negative (CoNS) isolates. These isolates were subjected to the disk-diffusion test to evaluate the bacterial resistance profile and then subjected to molecular identification of Staphylococcus aureus and analyses of the mecA gene through polymerase chain reaction. Of the 60 samples collected, 60 Staphylococcus spp. were isolated, of which 38 (63.33%) were classified as CoNS and 22 (36.67%) as CoPS. Of these, ten (45.45%) were identified as Staphylococcus aureus. The resistance profile of these isolates showed high resistance to different antibiotics, with 100% of the isolates resistant to chloramphenicol, clindamycin, and erythromycin, 98.33% resistant to doxycycline, 95% resistant to oxacillin, and 85% resistant to cefoxitin. Regarding the mecA gene, 27 (45%) samples were positive for the presence of this gene, and three (11.11%) were phenotypically sensitive to oxacillin and cefoxitin. This finding highlights the importance of researching the phenotypic profile of resistance to different antimicrobials and resistance genes in the different phases of pig rearing to identify the real risk of these isolates from a One Health perspective. The present study revealed the presence of samples resistant to different antibiotics in recently weaned production animal that had not been markedly exposed to antimicrobials as growth promoters or even as prophylactics. This information highlights the need for more research on the possible sharing of bacteria between sows and piglets, the environmental pressure within production environments, and the exposure of handlers during their transport, especially considering the community, hospital, and political importance of the presence of circulating resistant strains. | 2023 | 36634542 |
| 3127 | 19 | 0.9991 | Characterization of Bacteria and Antibiotic Resistance in Commercially Produced Cheeses Sold in China. ABSTRACT: The consumption of cheese in the People's Republic of China is increasing rapidly. Little is known about the microbiota, the presence of antibiotic-resistant bacteria, or the distribution of antibiotic resistance genes (ARGs) in commercially produced cheeses sold in China. This information is important for evaluating quality and safety. This study was conducted using 16S rRNA gene sequencing to assess the metagenomics of 15 types of cheese. Fourteen bacterial genera were detected, and Lactococcus, Lactobacillus, and Streptococcus were dominant based on number of sequence reads. Multidrug-resistant lactic acid bacteria (i.e., resistant to two or more types of antibiotic) were isolated from most of the types of cheese. Of these isolates, 100 and 91.7% were resistant to streptomycin and sulfamethoxazole, respectively, and genes involved in acquired resistance to streptomycin (strB) and sulfonamides (sul2) were detected with high frequency. To analyze the distribution of ARGs in the cheeses overall, 309 ARGs from eight categories and nine transposase genes were profiled. A total of 169 ARGs were detected in the 15 cheeses; their occurrence and abundance varied significantly between cheeses. Our study revealed diverse bacteria and ARGs in cheeses sold in China. The risks associated with multidrug resistance among dominant lactic acid bacteria are of great concern. | 2022 | 34855936 |