# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 972 | 0 | 0.9728 | Prevalence of antimicrobial resistance and integron gene cassettes in Escherichia coli isolated from yaks (Poephagus grunniens) in Aba Tibetan Autonomous Prefecture, China. BACKGROUND: Escherichia coli (E. coli) is one of the most relevant opportunistic pathogenic bacteria as it may cause severe morbidity and mortality in yaks (poephagus grunniens). In recent years, several kinds of antibiotics have been widely used in Tibetan areas to treat the bacterial diseases, resulting in serious repercussions on the bacterial antibiotic resistance in yaks. This investigation was conducted in order to determine the prevalence of antimicrobial resistance and integron gene cassettes in E. coli isolated from yaks in Aba Tibetan Autonomous Prefecture (Aba TAP), China. METHODS: A total of 278 non-duplicated fresh samples were collected from the yaks in Aba TAP for the isolation and identification of E. coli isolates. Antimicrobial susceptibility testing is performed by using the disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines (CLSI, 2013). Various antibiotic resistance genes and integron gene cassettes were detected by polymerase chain reaction (PCR) and sequencing. RESULTS: Overall, a total of 228 E. coli bacteria were isolated from the fresh faeces of yaks in four different geographical regions. 58% of those isolates showed multi-drug resistance capabilities (MDR) in our study. These isolated bacteria showed a high resistance rate to streptomycin (84%), cefotaxime (79%), amikacin (61%) and trimethoprim-sulfamethoxazole (54%). The most common antimicrobial resistance genes in the isolates were bla(CTX-M), sul1, aph (3')-IIa, aac (3)-IIa, aac (6')-Ib, tetB, with respective detection rates of 65%, 46%, 35%, 13%, 11%, and 10%. Furthermore, 66% and 6% of the strains carried Class 1 and 2 integrons, respectively. However, the class 3 integron was not detected. Gene cassette arrays in the class 1 integron included aadA1, aadA7, aadA5, aadA17, dfrA1, dfrA5, dfrA1-aadA1, dfrA12-aadA2 and dfrA17-aadA5. The most prevalent gene cassette was aadA1 (20%). For the class 2 integron, dfrA1-sat2-aadA1 (6%) and dfrA1-sat1-aadA1 (0.4%) were also detected as part of this research. CONCLUSION: High multi-drug resistance rates have been discovered, as well as a prevalence of antibiotic resistance genes and integron gene cassettes in the E. coli isolated from the faeces of yak. This might create a potential problem for treatment of the yaks' bacterial infections as well as food hygiene for humans. It is therefore urgently necessary to begin continuous surveillance and analysis of antibiotic resistance and integron cassettes in other bacteria from yaks. | 2017 | 28888884 |
| 1211 | 1 | 0.9723 | Molecular characterization of multidrug-resistant Escherichia coli of the phylogroups A and C in dairy calves with meningitis and septicemia. Escherichia coli is an important cause of septicemia (SEPEC) and neonatal meningitis (NMEC) in dairy calves. However, the diversity of virulence profiles, phylogroups, antimicrobial resistance patterns, carriage of integron structures, and fluoroquinolone (FQ) resistance mechanisms have not been fully investigated. Also, there is a paucity of knowledge about the virulence profiles and frequency of potential SEPEC in feces from calves with or without diarrhea. This study aimed to characterize the virulence potential, phylogroups, antimicrobial susceptibility, integron content, and FQ-resistance mechanisms in Escherichia coli isolated from calves with meningitis and septicemia. Additionally, the virulence genes (VGs) and profiles of E. coli isolated from diarrheic and non-diarrheic calves were compared between them and together with NMEC and SEPEC in order to identify shared profiles. Tissue and fluid samples from eight dairy calves with septicemia, four of which had concurrent meningitis, were processed for bacteriology and histopathology. Typing of VGs was assessed in 166 isolates from diverse samples of each calf. Selected isolates were evaluated for antimicrobial susceptibility by the disk diffusion test. Phylogroups, integron gene cassettes cartography, and FQ-resistance determinants were analyzed by PCR, sequencing, and bioinformatic tools. Furthermore, 109 fecal samples and 700 fecal isolates from dairy calves with or without diarrhea were evaluated to detect 19 VGs by uniplex PCR. Highly diverse VG profiles were characterized among NMEC and SEPEC isolates, but iucD was the predominant virulence marker. Histologic lesions in all calves supported their pathogenicity. Selected isolates mainly belonged to phylogroups A and C and showed multidrug resistance. Classic (dfrA17 and arr3-dfrA27) and complex (dfrA17-aadA5::ISCR1::bla(CTX-M-2)) class 1 integrons were identified. Target-site mutations in GyrA (S83L and D87N) and ParC (S80I) encoding genes were associated with FQ resistance. The VGs detected more frequently in fecal samples included f17G (50%), papC (30%), iucD (20%), clpG (19%), eae (16%), and afaE-8 (13%). Fecal isolates displaying the profiles of f17 or potential SEPEC were found in 25% of calves with and without diarrhea. The frequency of E. coli VGs and profiles did not differ between both groups (p > 0.05) and were identical or similar to those found in NMEC and SEPEC. Overall, multidrug-resistant E. coli isolates with diverse VG profiles and belonging to phylogroups A and C can be implicated in natural cases of meningitis and septicemia. Their resistance phenotypes can be partially explained by class 1 integron gene cassettes and target-site mutations in gyrA and parC. These results highlight the value of antimicrobial resistance surveillance in pathogenic bacteria isolated from food-producing animals. Besides, calves frequently shed potential SEPEC in their feces as commensals ("Trojan horse"). Thus, these bacteria may be disseminated in the farm environment, causing septicemia and meningitis under predisposing factors. | 2022 | 34982979 |
| 1536 | 2 | 0.9721 | Complete Genetic Analysis of Plasmids Carried by Two Nonclonal bla(NDM-5)- and mcr-1-Bearing Escherichia coli Strains: Insight into Plasmid Transmission among Foodborne Bacteria. Our objective was to characterize the genetic features of plasmids harbored by two genetically related, MCR-1 and NDM-5-producing Escherichia coli strains recovered from a chicken meat sample. The genetic profiles of all plasmids harbored by the two test strains, namely, 1106 and 1107, were determined by whole-genome sequencing, S1-pulsed-field gel electrophoresis (PFGE), Southern hybridization, and bioinformatics analysis. The transferability of plasmids harbored by the two strains was assessed by filter mating assay. Strains 1106 and 1107 were resistant to almost all the antibiotics, including colistin and fosfomycin, but remained susceptible to amikacin and tigecycline. The plasmids of p1107-NDM-5 and p1106-NDM-5 both contain a class I integron which lacks the ISAba125 element. The backbone of p1106-IncFII exhibited a high degree of similarity with that of p1106-NDM-5 and p1107-NDM-5, implying that events of plasmid fusion and resolution were involved in the formation of the two plasmids. The plasmids p1106-IncHI2MCR and p1107-IncHI2MCR belong to an IncHI2 replicon type, with three copies of ISApl1 being observed in p1106-IncHI2MCR, implying that the mcr-1 gene was transferable among bacteria that reside in the same food matrix. In this study, p1106-IncFIB, p1107-99K, p1107-111K, and p1107-118K were all found to be phage-like plasmids, with p1106-IncFIB and p1107-118K containing several virulence genes, including iroBCDEN, iucABCD, sitABCD, hlyF, and iss. Surprisingly, resistance genes such as aph(3')-Ia, sul3, and aac(3')-IId could also be found in p1107-118K, but resistance genes were not detected in other phage-like plasmids. In conclusion, enhanced surveillance is required to monitor and control the dissemination of various resistance determinants among foodborne pathogens. IMPORTANCE Carbapenem and colistin are last-resort antibiotics used to treat serious clinical infections caused by multidrug-resistant (MDR) bacterial pathogens. Plasmids encoding resistance to carbapenems and colistin have been reported in clinical pathogens in recent years, and yet few studies reported cocarriage of mcr and bla(NDM) genes in Escherichia coli strains of food origin. How plasmids encoding these two important resistance determinants are being evolved and transmitted in bacterial pathogens is not well understood. In this study, we investigated the genetic features of plasmids harbored by two nonclonal, mcr-1- and bla(NDM-5)-bearing E. coli strains (1106 and 1107) recovered from a fresh chicken meat sample to understand and provide evidence of the level and dynamics of MDR plasmid transmission. Our data confirmed that active plasmid fusion and resolution events were involved in the formation of plasmids that harbor multiple resistance genes, which provide insights into the further control of plasmid evolution in bacterial pathogens. | 2021 | 34468190 |
| 5213 | 3 | 0.9721 | Draft genome sequences of Limosilactobacillus fermentum IJAL 01 335, isolated from a traditional cereal fermented dough. Limosilactobacillus fermentum IJAL 01 335 was isolated from mawè, a spontaneously fermented cereal dough from Benin. The 1.83 Mb draft genome sequence (52.37% GC) comprises 154 contigs, 1,836 coding sequences, and 23 predicted antibiotic resistance genes, providing insights into its genetic features and potential application in food fermentation. | 2025 | 41170963 |
| 5618 | 4 | 0.9720 | An Epidemiological Study on Salmonella in Tibetan Yaks from the Qinghai-Tibet Plateau Area in China. Salmonella is an important foodborne pathogen that can cause a range of illnesses in humans; it has also been a key focus for monitoring in the field of public health, including gastroenteritis, sepsis, and arthritis, and can also cause a decline in egg production in poultry and diarrhea and abortion in livestock, leading to death in severe cases, resulting in huge economic losses. This study aimed to investigate the isolation rate, antimicrobial resistance, serotypes, and genetic diversity of Salmonella isolated from yak feces in various regions on the Qinghai-Tibet Plateau. A total of 1222 samples of yak dung were collected from major cities in the Qinghai-Tibet Plateau area, and the sensitivity of the isolated bacteria to 10 major classes of antibiotics was determined using the K-B paper disk diffusion method for drug susceptibility. Meanwhile, the serotypes of the isolated bacteria were analyzed using the plate agglutination test for serum antigens, and their carriage of drug resistance and virulence genes was determined using PCR and gel electrophoresis experiments. The isolated bacteria were also classified using MLST (Multi-Locus Sequence Typing). The overall isolation rate for Salmonella was 18.25% (223/1222), and the results of the antibiotic susceptibility tests showed that 98.65% (220/223) of the isolated bacteria were resistant to multiple antibiotics. In the 223 isolates of Salmonella, eight classes of 20 different resistance genes, 30 serotypes, and 15 different types of virulence genes were detected. The MLST analysis identified 45 distinct sequence types (STs), including five clonal complexes, of which ST34, ST11, and ST19 were the most common. These findings contribute valuable information about strain resources, genetic profiles, and typing data for Salmonella in the Qinghai-Tibet Plateau area, facilitating improved bacterial surveillance, identification, and control in yak populations. They also provide certain data supplements for animal Salmonella infections globally, filling research gaps. | 2024 | 39765601 |
| 8460 | 5 | 0.9719 | Correlation Analysis of the Transcriptome and Gut Microbiota in Salmo trutta Resistance to Aeromonas salmonicida. Aeromonas salmonicida is a major pathogenic bacterium that poses a significant threat to salmonid fish. Yadong County, located in the Xizang Autonomous Region, is renowned for its characteristic industry of Salmo trutta aquaculture. In recent years, the outbreak of Bacterial Gill Disease (BGD) has led to substantial economic losses for S. trutta farmers. Our prior research identified A. salmonicida as one of the primary culprits behind BGD. To mitigate the impact of A. salmonicida on S. trutta, we conducted a comprehensive study aimed at identifying genes associated with resistance to A. salmonicida. This involved transcriptome sequencing and 16S rRNA sequencing of intestinal flora, providing valuable insights for the study of disease resistance in S. trutta. In this study, we identified 324 genera with 5171 ASVs in the susceptible group and 293 genera with 5669 ASVs in the resistant group. Notably, Methylobacterium and Sphingomonas were common bacteria present in the salmon's gut, and their proportions remained relatively stable before and after infection. Shewanella, with its antagonistic relationship with Aeromonas, may play a crucial role in the salmon's defense against A. salmonicida. Several related genes were identified, including angptl4, cipcb, grasp, ccr9a, sulf1, mtmr11, B3GNT3, mt2, PLXDC1, and ank1b. | 2024 | 39458292 |
| 3178 | 6 | 0.9718 | Metagenomic analysis reveals the diversity, transmission and potential ecological risks of yak nasal bacteria-carried antibiotic resistance genes in the Sichuan region of Qinghai-Tibet plateau. The Qinghai-Tibet Plateau (QTP) and yaks play respectively vital roles in global and plateau ecosystems. Antibiotic resistance is a global threat to public health, with antibiotic resistance genes (ARGs) being one of the emerging contaminants. However, few studies have investigated the abundance and diversity of ARGs and mobile genetic elements (MGEs) in the yak upper respiratory tract and their surrounding pastures. Moreover, the possible pathways for ARG transmission within these ecosystems have not yet been elucidated. Therefore, we investigated the ARG profiles, MGE profiles, and ARG-carrying host bacteria in yaks and their pasture collected from Ganzi and Aba region in Sichuan Province. Metagenomic analyses showed that 22 ARG types and 5 MGEs types were identified in 18 samples. Multidrug resistance gene (mexT) and bacitracin resistance gene (bacA) was identiffed as hotspots, which may compromise medical treatment options. Co-occurrence network analysis revealed that 12 bacterial genera may be potential hosts at the genus level. The enrich of ARGs and MGEs diversity were observed in QTP (Sichuan province) pasture ecosystems which demands evidence-based interventions to mitigate ARGs transmission risks. | 2025 | 40373403 |
| 7740 | 7 | 0.9716 | Diversity, functions, and antibiotic resistance genes of bacteria and fungi are examined in the bamboo plant phyllosphere that serve as food for the giant pandas. The phyllosphere of bamboo is rich in microorganisms that can disrupt the intestinal microbiota of the giant pandas that consume them, potentially leading to their death. In the present study, the abundance, diversity, biological functions (e.g., KEGG and CAZyme), and antibiotic resistance genes (ARGs) of bacteria and fungi in two bamboo species phyllosphere (Chimonobambusa szechuanensis, CS; Bashania fangiana, BF) in Daxiangling Nature Reserve (an important part of the Giant Panda National Park) were investigated respectively by amplicon sequencing of the whole 16S rRNA and ITS1-ITS2 genes on PacBio Sequel and whole-metagenome shotgun sequencing on Illumina NovaSeq 6000 platform. The results suggested that there were respectively 18 bacterial and 34 fungi biomarkers between the phyllosphere of the two species of bamboo. Beta diversity of bacteria and fungi communities exited between the two bamboos according to the (un)weighted UniFrac distance matrix. Moreover, the functional analysis showed that the largest relative abundance was found in the genes related to metabolism and global and overview maps. Glycoside hydrolases (GHs) and glycosyl transferases (GTs) have a higher abundance in two bamboo phyllospheres. Co-occurrence network modeling suggested that bacteria and fungi communities in CS phyllosphere employed a much more complex metabolic network than that in BF, and the abundance of multidrug, tetracycline, and glycopeptide resistance genes was higher and closely correlated with other ARGs. This study references the basis for protecting bamboo resources foraged by wild giant pandas and predicts the risk of antibiotic resistance in bamboo phyllosphere bacterial and fungal microbiota in the Giant Panda National Park, China. | 2025 | 39168909 |
| 3064 | 8 | 0.9716 | High Diversity but Monodominance of Multidrug-Resistant Bacteria in Immunocompromised Pediatric Patients with Acute Lymphoblastic Leukemia Developing GVHD Are Not Associated with Changes in Gut Mycobiome. Graft-versus-host disease (GvHD) is a severe complication after hematopoietic stem cell transplantation (HSCT). Our study focused on identifying multidrug-resistant (MDR) gut bacteria associated with GvHD-prone guts and association with gut microbiota (GM) diversity, bacteriome, and mycobiome composition in post-HSCT patients. We examined 11 pediatric patients with acute lymphoblastic leukemia (ALL), including six with GvHD, within three time points: seven days pre-HSCT, seven days post-, and 28 days post-HSCT. The gut microbiome and its resistome were investigated using metagenomic sequencing, taxonomically classified with Kraken2, and statistically evaluated for significance using appropriate tests. We observed an increase in the abundance of MDR bacteria, mainly Enterococcus faecium strains carrying msr(C), erm(T), aac(6')-li, dfrG, and ant(6)-la genes, in GvHD patients one week post-HSCT. Conversely, non-GvHD patients had more MDR beneficial bacteria pre-HSCT, promoting immunosurveillance, with resistance genes increasing one-month post-HSCT. MDR beneficial bacteria included the anti-inflammatory Bacteroides fragilis, Ruminococcus gnavus, and Turicibacter, while most MDR bacteria represented the dominant species of GM. Changes in the gut mycobiome were not associated with MDR bacterial monodominance or GvHD. Significant α-diversity decline (Shannon index) one week and one month post-HSCT in GvHD patients (p < 0.05) was accompanied by increased Pseudomonadota and decreased Bacteroidota post-HSCT. Our findings suggest that MDR commensal gut bacteria may preserve diversity and enhance immunosurveillance, potentially preventing GvHD in pediatric ALL patients undergoing HSCT. This observation has therapeutic implications. | 2023 | 38136701 |
| 1354 | 9 | 0.9716 | The prevalence, antibiotic resistance and multilocus sequence typing of colistin-resistant bacteria isolated from Penaeus vannamei farms in earthen ponds and HDPE film-lined ponds in China. The aquaculture environment, especially the culture ponds and aquaculture products, is considered to be an important reservoir of colistin resistance genes. However, systematic investigations of colistin resistance in Penaeus vannamei farming in different culture modes are scarce. In this study, a total of 93 non-duplicated samples were collected from P. vannamei farms in five cities in China from 2019 to 2021. The prevalence, antibiotic resistance and multilocus sequence typing (MLST) of colistin-resistant bacteria were measured and analysed. The results showed that among the 1601 isolates in P. vannamei and its environmental samples, the pollution of colistin-resistant bacteria was serious (the overall prevalence was 37.3% and 28.8%, respectively), regardless of the earthen pond or high-density polyethylene (HDPE) film-lined pond. Among 533 isolates, the prevalence of mobile colistin resistance (mcr) genes, mcr-1, was the highest (60%, 320/533), followed by mcr-4 (1.5%, 8/533), mcr-8 (0.9%, 5/533), mcr-10 (0.6%, 3/533) and mcr-7 (0.4%, 2/533). The prevalence of mcr-1 in earthen ponds was significantly higher than that in HDPE film-lined ponds (67.5% vs. 49.1%, p < .001). The dominant strain carrying mcr-1 was Bacillus spp. (54.1%, 173/320), followed by Enterobacter spp. (8.1%, 26/320), Staphylococcus spp. (6.3%, 20/320) and Aeromonas spp. (5.3%, 17/320). The antibiotic resistance profiles of 173 Bacillus spp. varied among different sampling locations and culture types. These isolates were highly resistant to cefepime, ceftriaxone, trimethoprim-sulfamethoxazole and ceftiofur (>45%), and multidrug-resistant isolates were common (62.4%, 108/173). Sequence type (ST) 26 (37/66, 56%) was found to be the most prevalent ST in mcr-1-positive Bacillus cereus isolated from the aquaculture environment. In summary, our study pointed out that it is necessary to continuously monitor antibiotic usage and its residues regardless of the pond types, especially with regard to critical drugs such as colistin. | 2022 | 35841601 |
| 1333 | 10 | 0.9714 | Virulence-encoding genes related to extraintestinal pathogenic E. coli and multidrug resistant pattern of strains isolated from neonatal calves with different severity scores of umbilical infections. Umbilical infections in calves comprise a major cause of neonatal mortality and have been related to a variety of microorganisms. E. coli is an opportunistic enteropathogen characterized by a diversity of virulence factors (VF). Nonetheless, the gene profiles that encode VF associated with umbilical infections in calves and their effect on the clinical severity remains unclear. In this scenario, microbial identification (with an emphasis on E. coli), was carried out among 150 neonatal calves (≤30 days of age) with umbilical infections, where the omphalopathies were clinically scored as mild, moderate, or severe. Also, a panel of 16 virulence-encoding genes related to extraintestinal pathogenic E. coli (ExPEC) were investigated, i.e., fimbriae/adhesins (sfa/focDEa, papA, papC, afaBC), toxins (hlyA, sat, cnf1, cdt), siderophores (iroN, irp2, iucD, ireA), invasins (ibeA), and serum resistance (ompT, traT, kpsMT II). Bacteria and yeasts isolates were identified using mass spectrometry. Bacteria, yeasts, and fungi were isolated in 94.7% (142/150) of neonatal calves sampled. E. coli was the agent most frequently isolated (59/150 = 39.3%), in pure culture (27/59 = 45.8%) and combined infections (32/59 = 54.2%), although a great variety (n = 83) of other species of microorganisms were identified. Clinical severity scores of 1, 2, and 3 were observed in 32.2% (19/59), 23.7% (14/59), and 44.1% (26/59) of E. coli infections, respectively. The ExPEC genes detected were related to serum resistance (traT, 42/59 = 72.2%; ompT, 35/59 = 59.3%, kpsMTII, 10/59 = 17%), invasins (ibeA, 11/59 = 18.6%), siderophores (iucD, 9/59 = 15.3%; iroN, 8/59 = 13.6%), and adhesins/fimbriae (papA, 8/59 = 13.6%; papC, 15/59 = 9.6%). The presence of each virulence gene was not associated with the case's clinical score. Among all isolates, 89.8% (53/59) showed in vitro resistance to sulfamethoxazole/trimethoprim and 59.3% to ampicillin (35/59), while 94.1% (55/59) revealed a multidrug resistant profile. Great complexity of bacteria, yeast, and fungi species was identified, reinforcing the umbilical infections of neonatal calves as a polymicrobial disorder. The high occurrence of E. coli (39.3%) highlights the role of this pathogen in the etiology of umbilical infections in calves. Furthermore, a panel of ExPEC genes was investigated for the first time among calves that were clinically scored for case severity. The high prevalence of traT and ompT indicates that these serum resistance-related genes could be used as biomarkers for further investigations of ExPEC isolates from umbilical infections. Our results contribute to the etiological investigation, clinical severity scoring, antimicrobial resistance pattern, and virulence-related to ExPEC genes involved in umbilical infections of neonatal calves. | 2023 | 36427660 |
| 6381 | 11 | 0.9713 | Occurrence and distribution of antibiotic resistance genes in Elymus nutans silage from different altitudes on the Qinghai-Tibetan Plateau. INTRODUCTION: Antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) have attracted more attentions in fermented feed recently. However, little information is available on the occurrence and distribution of ARGs in ensiled forages in the alpine region of the Qinghai-Tibetan plateau (QTP) with an extremely harsh environment. METHODS: The study investigated the distribution and spread mechanism of ARB and ARGs in Elymus nutans silage along 2600 m (low), 3600 m (medium) and 4600 m (high) altitude in the QTP. RESULTS: The major ARG types in Elymus nutans silage were multidrug, aminoglycoside, bacitracin, beta-lactam and polymyxin, while tnpA and IS91 were the dominant mobile genetic elements (MGEs) subtypes in the Elymus nutans silage. The dominant ARGs were mainly carried by Pantoea, Enterobacter, Serratia, and Lelliottia. Although altitudinal gradient had no influence on the diversity or abundance of other ARGs and MGEs in the Elymus nutans silage (p > 0.05), the network co-occurrence patterns among ARGs, MGEs, and bacteria in high-altitude silage were more complex than that in low- and medium-altitude silages. The dominant clinical ARGs in the alpine silage were bacA and acrF, and the abundance of clinical ARGs decreased with prolonged fermentation time. DISCUSSION: This study provides important data on the status of ARGs in ensiled forage from the alpine region of the QTP. | 2025 | 40458713 |
| 1223 | 12 | 0.9712 | Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran. BACKGROUND: Calf diarrhea is a major economic concern in bovine industry all around the world. This study was carried out in order to investigate distribution of virulence genes, pathotypes, serogroups and antibiotic resistance properties of Escherichia coli isolated from diarrheic calves. RESULTS: Totally, 76.45% of 824 diarrheic fecal samples collected from Isfahan, Chaharmahal, Fars and Khuzestan provinces, Iran were positive for E. coli and all of them were also positive for cnf2, hlyA, cdtIII, f17c, lt, st, stx1, eae, ehly, stx2 and cnf1 virulence genes. Chaharmahal had the highest prevalence of STEC (84.61%), while Isfahan had the lowest (71.95%). E. coli serogroups had the highest frequency in 1-7 days old calves and winter season. Distribution of ETEC, EHEC, AEEC and NTEC pathotypes among E. coli isolates were 28.41%, 5.07%, 29.52% and 3.49%, respectively. Statistical analyses were significant for presence of bacteria between various seasons and ages. All isolates had the high resistance to penicillin (100%), streptomycin (98.25%) and tetracycline (98.09%) antibiotics. The most commonly detected resistance genes were aadA1, sul1, aac[3]-IV, CITM, and dfrA1. The most prevalent serogroup among STEC was O26. CONCLUSIONS: Our findings should raise awareness about antibiotic resistance in diarrheic calves in Iran. Clinicians should exercise caution when prescribing antibiotics. | 2014 | 25052999 |
| 3488 | 13 | 0.9711 | Characteristics of Antibiotic Resistance Genes and Antibiotic-Resistant Bacteria in Full-Scale Drinking Water Treatment System Using Metagenomics and Culturing. The contamination of antibiotic resistance genes (ARGs) may directly threaten human health. This study used a metagenomic approach to investigate the ARG profile in a drinking water treatment system (DWTS) in south China. In total, 317 ARG subtypes were detected; specifically, genes encoding bacitracin, multidrug, and sulfonamide were widely detected in the DWTS. Putative ARG hosts included Acidovorax (6.0%), Polynucleobacter (4.3%), Pseudomonas (3.4%), Escherichia (1.7%), and Klebsiella (1.5%) as the enriched biomarkers in the DWTS, which mainly carried bacitracin, beta-lactam, and aminoglycoside ARGs. From a further analysis of ARG-carrying contigs (ACCs), Stenotrophomonas maltophilia and Pseudomonas aeruginosa were the most common pathogens among the 49 ACC pathogens in the DWTS. The metagenomic binning results demonstrated that 33 high-quality metagenome-assembled genomes (MAGs) were discovered in the DWTS; particularly, the MAG identified as S. maltophilia-like (bin.195) harbored the greatest number of ARG subtypes (n = 8), namely, multidrug (n = 6; smeD, semE, multidrug_transporter, mexE, semB, and smeC), beta-lactam (n = 1; metallo-beta-lactamase), and aminoglycoside [n = 1; aph(3')-IIb]. The strong positive correlation between MGEs and ARG subtypes revealed a high ARG dissemination risk in the DWTS. Based on the pure-culture method, 93 isolates that belong to 30 genera were recovered from the DWTS. Specifically, multidrug-resistant pathogens and opportunistic pathogens such as P. aeruginosa, Bacillus cereus, and S. maltophilia were detected in the DWTS. These insights into the DWTS's antibiotic resistome indicated the need for more comprehensive ARG monitoring and management in the DWTS. Furthermore, more effective disinfection methods need to be developed to remove ARGs in DWTSs, and these findings could assist governing bodies in the surveillance of antibiotic resistance in DWTSs. | 2021 | 35273579 |
| 3547 | 14 | 0.9711 | Occurrence of 40 sanitary indicators in French digestates derived from different anaerobic digestion processes and raw organic wastes from agricultural and urban origin. This study investigated the sanitary quality of digestates resulting from the mesophilic anaerobic digestion (AD) of urban and agricultural organic wastes (OWs). 40 sanitary indicators, including pathogenic bacteria, antimicrobial resistance genes, virulence factor genes, and mobile genetic elements were evaluated using real-time PCR and/or droplet digital PCR. 13 polycyclic aromatic hydrocarbons (PAHs) and 13 pharmaceutical products (PHPs) were also measured. We assessed agricultural OWs from three treatment plants to study the effect of different AD processes (feeding mode, number of stages, pH), and used three laboratory-scale reactors to study the effect of different feed-supplies (inputs). The lab-scale reactors included: Lab1 fed with 97% activated sludge (urban waste) and 3% cow manure; Lab2 fed with 85% sludge-manure mixture supplemented with 15% wheat straw (WS); and Lab3 fed with 81% sludge-manure mixture, 15% WS, and 4% zeolite powder. Activated sludge favored the survival of the food-borne pathogens Clostridium perfringens and Bacillus cereus, carrying the toxin-encoding genes cpe and ces, respectively. Globally, the reactors fed with fecal matter supplemented with straw (Lab2) or with straw and zeolite (Lab3) had a higher hygienization efficiency than the reactor fed uniquely with fecal matter (Lab1). Three pathogenic bacteria (Enterococcus faecalis, Enterococcus faecium, and Mycobacterium tuberculosis complex), a beta-lactam resistance gene (bla (TEM)), and three mobile genetic elements (intI1, intI2, and IS26) were significantly decreased in Lab2 and Lab3. Moreover, the concentrations of 11 PAHs and 11 PHPs were significantly lower in Lab2 and Lab3 samples than in Lab1 samples. The high concentrations of micropollutants, such as triclosan, found in Lab1, could explain the lower hygienization efficiency of this reactor. Furthermore, the batch-fed reactor had a more efficient hygienization effect than the semi-continuous reactors, with complete removal of the ybtA gene, which is involved in the production of the siderophore yersiniabactin, and significant reduction of intI2 and tetO. These data suggest that it is essential to control the level of chemical pollutants in raw OWs to optimize the sanitary quality of digestates, and that adding co-substrate, such as WS, may overcome the harmful effect of pollutants. | 2024 | 39165575 |
| 3485 | 15 | 0.9711 | Abundance and Diversity of Phages, Microbial Taxa, and Antibiotic Resistance Genes in the Sediments of the River Ganges Through Metagenomic Approach. In this study, we have analyzed the metagenomic DNA from the pooled sediment sample of the river Ganges to explore the abundance and diversity of phages, microbial community, and antibiotic resistance genes (ARGs). Utilizing data from Illumina platform, 4,174 (∼0.0013%) reads were classified for the 285 different DNA viruses largely dominated by the group of 260 distinctive phages (3,602 reads, ∼86.3%). Among all, Microcystis (782 hits), Haemophilus (403), Synechococcus (386), Pseudomonas (279), Enterococcus (232), Bacillus (196), Rhodococcus (166), Caulobacter (163), Salmonella (146), Enterobacteria (143), Mycobacterium and (128) phages show the highest abundance and account for ∼90% of the total identified phages. In addition, we have also identified corresponding host pertaining to these phages. Mainly, Proteobacteria (∼69.3%) dominates the microbial population structure. Primarily, orders such as Caulobacterales (∼28%), Burkholderiales (∼13.9%), Actinomycetales (∼13.7%), and Pseudomonadales (∼7.5%) signify the core section. Furthermore, 21,869 (∼0.00695%) reads were classified in 20 ARG types (classes) and 240 ARGs (subtypes), among which 4 ARG types, namely multidrug resistance (12,041 reads, ∼55%), bacitracin (3,202 reads, ∼15%), macrolide-lincosamide-streptogramin (1,744 reads, ∼7.98%), and fosmidomycin (990 reads, ∼4.53%), have the highest abundance. Simultaneously, six resistance mechanisms were also recognized with the dominance of antibiotic efflux (72.8%, 15,919 reads). The results unveil the distribution of (pro)-phages; microbial community; and various ARGs in the Ganges river sediments. | 2021 | 33913739 |
| 1225 | 16 | 0.9710 | Escherichia coli serogroups in slaughterhouses: Antibiotic susceptibility and molecular typing of isolates. This study aimed to investigate the contamination of carcasses and slaughterhouse environment with Escherichia coli O157:H7 and non-O157 serogroups (O45:H2, O103:H2, O121:H19, O145:H28, O26:H11, O111:H8). For this purpose, a total of 150 samples (30 carcasses, 30 shredding units, 30 knives, 30 slaughterhouse waste water and 30 wall surfaces) were collected from 5 different slaughterhouses in Kayseri, Turkey. The conventional and molecular methods were performed in order to detect Escherichia coli and its serogroups. Of the 150 samples, 55 (36%) were found to be contaminated with E. coli. Among isolates, E. coli serogroup (O157:H7) were detected in 2 (11%) carcass and 2 (11%) wastewater samples. None of the E. coli isolates harbored tested genes (stx1, stx2, eaeA, and hylA). Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of multidrug-resistant bacteria. It was also deduced that these isolates resistance to different antibiotics could be hazardous for public health. | 2022 | 35427957 |
| 1645 | 17 | 0.9710 | Epidemiological investigation and β-lactam antibiotic resistance of Riemerella anatipestifer isolates with waterfowl origination in Anhui Province, China. Riemerella anatipestifer (R. anatipestifer) is a highly pathogenic and complex serotypes waterfowl pathogen with inherent resistance to multiple antibiotics. This study was aimed to investigate the antibiotic resistance characteristics and genomic features of R. anatipestifer isolates in Anhui Province, China in 2023. A total of 287 cases were analysed from duck farms and goose farms, and the R. anatipestifer isolates were subjected to drug resistance tests for 30 antimicrobials. Whole genome sequencing (WGS) and bioinformatics analysis were performed on the bacterial genomes, targeting the β-lactam resistance genes. The results showed that a total of 74 isolates of R. anatipestifer were isolated from 287 cases, with a prevalence of 25.8%. The antimicrobial susceptibility testing (AST) revealed that all the 74 isolates were resistant to multiple drugs, ranging from 13 to 26 kinds of drugs. Notably, these isolates showed significant resistance to aminoglycosides and macrolides, which are also commonly used in clinical practices. Data revealed the presence of several β-lactamase-related genes among the isolates, including a novel bla(RASA-1) variant (16.2%), the class A extended-spectrum β-lactamase bla(RAA-1) (12.2%), and a bla(OXA-209) variant (98.6%). Functional analysis of the variants bla(RASA-1) and bla(OXA-209) showed that the bla(RASA-1) variant exhibited activity against various β-lactam antibiotics while their occurrence in R. anatipestifer were not common. The bla(OXA-209) variant, on the other hand, did not perform any β-lactam antibiotic resistance. Furthermore, we observed that bla(RAA-1) could undergo horizontal transmission among different bacteria via the insertion sequence IS982. In conclusion, this study delves into the high prevalence of R. anatipestifer infection in waterfowl in Anhui, China. The isolated strains exhibit severe drug resistance issues, closely associated with the prevalence of antibiotic resistance genes (ARG). Additionally, our research investigates the β-lactam antibiotic resistance mechanism in R. anatipestifer. | 2024 | 38387287 |
| 1340 | 18 | 0.9709 | Prevalence, Virulence, and Antimicrobial Resistance of Campylobacter spp. in Raw Milk, Beef, and Pork Meat in Northern Poland. The purpose of this study was to determine whether raw milk, unpasteurized dairy products, pork, and beef available for sale in the Kujawsko-Pomorskie and Wielkopolska regions in Poland are contaminated with Campylobacter spp. bacteria and may be a potential source of infection. For isolated strains, antibiotic susceptibility and the presence of genes responsible for virulence were examined. Material for research included 1058 food samples collected between 2014 and 2018 with 454 samples of raw milk and unpasteurized dairy products (milk from vending machines, milk from owners of dairy cows, cheese, milk cream) and 604 samples of raw meat (pork, beef). The results indicated that 9.3% of the samples were positive for Campylobacter spp., and Campylobacter jejuni was predominant in this study. Campylobacter bacteria was not found in milk collected from vending machines, as well as cheese and milk cream samples. Campylobacter was noted in 12.7% of beef samples, 11.8% of raw milk purchased from individual suppliers, and 10.9% of pork samples. Resistance to erythromycin (2.0%), azithromycin (3.1%), gentamicin (4.1%), tetracycline (65.3%), and ciprofloxacin (71.4%) was determined using the disc diffusion method. Furthermore, the prevalence of racR, sodB, csrA, virB11, cdtB, iam, and wlaN genes were examined using the PCR method. The sodB, csrA, and cdtB genes exhibited the highest detection rate, but none of the genes were identified in 100% of the isolates. Statistically significant differences between the presence of virulence marker genes, including for iam, racR, and csrA markers, were noted among different sources of the isolates. Differences in the distribution of iam, wlaN, and virB11 were also shown between C. jejuni and C. coli strains. As a result of the analysis, it has been concluded that unpasteurized milk, beef, and pork could be a sources of Campylobacter pathogens. Moreover, this study revealed virulent properties of Campylobacter isolated from such food products and high resistance rates to fluoroquinolones, which may represent difficulties in campylobacteriosis treatment. | 2019 | 31533265 |
| 1506 | 19 | 0.9709 | Detection of Five mcr-9-Carrying Enterobacterales Isolates in Four Czech Hospitals. The aim of this study was to report the characterization of the first mcr-positive Enterobacterales isolated from Czech hospitals. In 2019, one Citrobacter freundii and four Enterobacter isolates were recovered from Czech hospitals. The production of carbapenemases was examined by a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) imipenem hydrolysis assay. Additionally, bacteria were screened for the presence of carbapenemase-encoding genes and plasmid-mediated colistin resistance genes by PCR. To define the genetic units carrying mcr genes, the genomic DNAs of mcr-carrying clinical isolates were sequenced on the PacBio Sequel I platform. Results showed that all isolates carried bla(VIM)- and mcr-like genes. Analysis of whole-genome sequencing (WGS) data revealed that all isolates carried mcr-9-like alleles. Furthermore, the three sequence type 106 (ST106) Enterobacter hormaechei isolates harbored the bla(VIM-1) gene, while the ST764 E. hormaechei and ST95 C. freundii included bla(VIM-4) Analysis of plasmid sequences showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. Additionally, at least one multidrug resistance (MDR) region was identified in each mcr-9-carrying IncHI2 plasmid. The bla(VIM-4) gene was found in the MDR regions of p48880_MCR_VIM and p51929_MCR_VIM. In the three remaining isolates, bla(VIM-1) was localized on plasmids (∼55 kb) exhibiting repA-like sequences 99% identical to the respective gene of pKPC-CAV1193. In conclusion, to the best of our knowledge, these 5 isolates were the first mcr-9-positive bacteria of clinical origin identified in the Czech Republic. Additionally, the carriage of the bla(VIM-1) on pKPC-CAV1193-like plasmids is described for the first time. Thus, our findings underline the ongoing evolution of mobile elements implicated in the dissemination of clinically important resistance determinants.IMPORTANCE Infections caused by carbapenemase-producing bacteria have led to the revival of polymyxins as the "last-resort" antibiotic. Since 2016, several reports describing the presence of plasmid-mediated colistin resistance genes, mcr, in different host species and geographic areas were published. Here, we report the first detection of Enterobacterales carrying mcr-9-like alleles isolated from Czech hospitals in 2019. Furthermore, the three ST106 Enterobacter hormaechei isolates harbored bla(VIM-1), while the ST764 E. hormaechei and ST95 Citrobacter freundii isolates included bla(VIM-4) Analysis of WGS data showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. bla(VIM-4) was found in the MDR regions of IncHI2 plasmids, while bla(VIM-1) was localized on pKPC-CAV1193-like plasmids, described here for the first time. These findings underline the ongoing evolution of mobile elements implicated in dissemination of clinically important resistance determinants. Thus, WGS characterization of MDR bacteria is crucial to unravel the mechanisms involved in dissemination of resistance mechanisms. | 2020 | 33298573 |