Core and variable antimicrobial resistance genes in the gut microbiomes of Chinese and European pigs

Monitoring the prevalence of antimicrobial resistance genes(ARGs)is vital for addressing the global crisis of antibiotic-resistant bacterial infections.Despite its importance,the characterization of ARGs and microbiome structures,as well as the identification of indicators for routine ARG monitoring in pig farms,are still lacking,particularly concerning variations in antimicrobial exposure in different countries or regions.Here,metagenomics and random forest machine learning were used to elucidate the ARG profiles,microbiome structures,and ARG contamination indicators in pig manure under different antimicrobial pressures between China and Europe.Results showed that Chinese pigs exposed to high-level antimicrobials exhibited higher total and plasmid-mediated ARG abundances compared to those in European pigs(P<0.05).ANT(6)-Ib,APH(3')-IIIa,and tet(40)were identified as shared core ARGs between the two pig populations.Furthermore,the core ARGs identified in pig populations were correlated with those found in human populations within the same geographical regions.Lactobacillus and Prevotella were identified as the dominant genera in the core microbiomes of Chinese and European pigs,respectively.Forty ARG markers and 43 biomarkers were able to differentiate between the Chinese and European pig manure samples with accuracies of 100%and 98.7%,respectively.Indicators for assessing ARG contamination in Chinese and European pigs also achieved high accuracy(r=0.72-0.88).Escherichia flexneri in both Chinese and European pig populations carried between 21 and 37 ARGs.The results of this study emphasize the importance of global collaboration in reducing antimicrobial resistance risk and provide validated indicators for evaluating the risk of ARG contamination in pig farms.

Prevalence and antimicrobial resistance of non-typhoid Solmonella in military personnel,1988-2013

Objective:To describe the spanning 25 years data for the occurrence, magnitude, and trends regarding antimicrobial resistance of non-typhoidalSalmonella (NTS) isolated from non-immune travelers to Thailand participating in joint military operations.Methods:A total of 355 NTS isolates, obtained from 2052 fecal samples from US soldiers deployed for military maneuvers in Thailand during 1988-2013, were examined for NTS serogroup/serotypes and tested for antimicrobial susceptibility by disk diffusion to these 10 antibiotics:ampicillin, azithromycin (AZM), ciprofloxacin, colistin, gentamicin, kanamycin, nalidixic acid, streptomycin (STR), tetracycline (TET), and trimethoprim/sulfamethoxazole. Identified AZM-resistant NTS isolates were further evaluated for their minimal inhibitory concentration by the E-test method.Results:NTS infections accounted for 17.3％ (355/2052), including 11 serogroups and 50 different serotypes. The most prevalent serogroup wasSalmonella group C2-C3 (35.8％, 127/355) followed by groups B (21.1％, 75/355) and C1 (18.6％, 66/355). Identified serotypes includedSalmonellahadar (n=60),Salmonellarissen (n=45), andSalmonella blockley (n=34). Among the predominate serogroups, antimicrobial resistance was consistently high against TET (76.9％, 273/355) followed by STR (40.8％, 145/355). OneSalmonella senftenberg isolate demonstrated decreased ciprofloxacin susceptibility. Most isolates (94.6％) were resistant to one or more antimicrobials, and the most common multidrug resistance was TET-STR-nalidixic acid (11.5％, 41/355).Conclusions:The prevalence of NTS serotypes and the growing magnitude of antibiotic resistant bacteria isolated from deployed US military in Thailand are documented from 1988-2013. This study demonstrates the antibiotic resistance profiles, highlighting the effectiveness of AZM that is a first-line treatment for travelers to Southeast Asia. AZM-resistant NTS isolates are periodically observed over a 25-year period. Hence, the ongoing surveillance and prevalence efforts are required to monitor NTS resistant strains causing further treatment failure.

A New High-throughput Real-time PCR Assay for the Screening of Multiple Antimicrobial Resistance Genes in Broiler Fecal Samples from China

Objective Antimicrobial resistance(AMR)has become a global concern and is especially severe in China.To effectively and reliably provide AMR data,we developed a new high-throughput real-time PCR assay based on microfluidic dynamic technology,and screened multiple AMR genes in broiler fecal samples.Methods A high-throughput real-time PCR system with an new designed integrated fluidic circuit assay were performed AMR gene detection.A total of 273 broiler fecal samples collected from two geographically separated farms were screened AMR genes.Results The new assay with limits of detection ranging from 40.9 to 8,000 copies/reaction.The sensitivity rate,specificity rate,positive predictive value,negative predictive value and correct indices were 99.30%,98.08%,95.31%,99.79%,and 0.9755,respectively.Utilizing this assay,we demonstrate that AMR genes are widely spread,with positive detection rates ranging from 0 to 97.07%in 273 broiler fecal samples.bla CTX-M,bla TEM,mcr-1,fex A,cfr,optr A,and int I1 showed over 80%prevalence.The dissemination of AMR genes was distinct between the two farms.Conclusions We successfully established a new high-throughput real-time PCR assay applicable to AMR gene surveillance from fecal samples.The widespread existence of AMR genes detected in broiler farms highlights the current and severe problem of AMR.

Antimicrobial susceptibility testing before first-line treatment for Helicobacter pylori infection in patients with dual or triple antibiotic resistance

To evaluate the efficacy of antimicrobial susceptibility-guided therapy before first-line treatment for infection in patients with dual or triple antibiotic resistance.METHODSA total of 1034 patients infected by Helicobacter pylori (H. pylori) during 2013-2014 were tested for antimicrobial susceptibility. 157 of 1034 (15%) patients showed resistance to two (127/1034; 12%) and to three (30/1034; 3%) antibiotics. Sixty-eight patients with dual H. pylori-resistance (clarithromycin, metronidazole or levofloxacin) were treated for 10 d with triple therapies: OAL (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and levofloxacin 500 mg b.i.d.) 43 cases, OAM (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and metronidazole 500 mg b.i.d.) 12 cases and OAC (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d.) 13 cases based on the antimicrobial susceptibility testing. Twelve patients showed triple H. pylori-resistance (clarithromycin, metronidazole and levofloxacin) and received for 10 d triple therapy with OAR (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and rifabutin 150 mg b.i.d.). Eradication was confirmed by 13C-urea breath test. Adverse effects and compliance were assessed by a questionnaire.RESULTSIntention-to-treat eradication rates were: OAL (97.6%), OAM (91.6%), OAC (92.3%) and OAR (58.3%). Cure rate was significantly higher in naïve patients treated with OAR-10 compared to patients who had two or three previous treatment failures (83% vs 33%). Adverse events rates for OAL, OAM, OAC and OAR were 22%, 25%, 23% and 17%, respectively, all of them mild-moderate.CONCLUSIONAntimicrobial susceptibility-guided triple therapies during 10 d for first-line treatment leads to an eradication rate superior to 90% in patients with dual antibiotic H. pylori resistance.

Detection of antimicrobial resistance and virulence-related genes in Streptococcus uberis and Streptococcus parauberis isolated from clinical bovine mastitis cases in northwestern China

The objectives of this study were to investigate antimicrobial resistance of Streptococcus uberis and Streptococcus parauberis isolated from cows with bovine clinical mastitis in China and to examine the distribution of resistance-and virulence-related gene patterns.Antimicrobial susceptibility was determined by the E-test.Genes encoding antimicrobial resistance and invasiveness factors were examined by PCR.A total of 27 strains were obtained from 326 mastitis milk samples.Streptococcus parauberis isolates(n=11)showed high resistance to erythromycin(90.9%),followed by tetracycline(45.5%),chloramphenicol(36.4%)and clindamycin(27.3%).Streptococcus uberis isolates(n=16)were highly resistant to tetracycline(81.3%)and clindamycin(62.5%).Both species were susceptible to ampicillin.The most prevalent resistance gene in S.uberis was tetM(80.0%),followed by blaZ(62.5%)and ermB(62.5%).However,tetM,blaZ,and ermB genes were only found in 27.3,45.5,and 27.3%,respectively,of S.parauberis.In addition,all of the isolates carried at least one selected virulence-related gene.The most prevalent virulence-associated gene pattern in the current study was sua+pauA/skc+gapC+hasC detected in 22.2%of the strains.One S.uberis strain carried 7 virulence-associated genes and belonged to the sua+pauA/skc+gapC+cfu+hasA+hasB+hasC pattern.More than 59.3%of analysed strains carried 4 to 7 virulence-related genes.Our findings demonstrated that S.parauberis and S.uberis isolated from clinical bovine mastitis cases in China exhibited diverse molecular ecology,and that the strains were highly resistant to antibiotics commonly used in the dairy cow industry.The data obtained in the current study contribute to a better understanding of the pathogenesis of bacteria in mastitis caused by these pathogens,and the findings are relevant to the development of multivalent vaccines and targeted prevention procedures.

Antimicrobial Resistance and Genotype Analysis of Extended-Spectrum-β-Lactamase-Producing Proteus Mirabilis

To analyse the genotypes of clinical isolates of Extended-Spectrum-β-Lactamase-Producing (ESBL-producing) Proteus mirabilis (P. mirabilis) and the mechanisms of antimicrobial resistance, to guide reasonable use of antibiotics and to avoid nosocomial outbreak infections by ESBL-producing P. mirabilis. 125 clinical isolates of P. mirabilis were collected from the Drug-Resistant Bacteria Surveillance Center of Anhui Province (from Jan 2009 to May 2010). Searching for the genotypes of ESBLs was perfomed by PCR amplification and DNA sequencing, and performed conjugation test simultaneously. Among ESBL-producing strains, CTX-M was the major genotype (3 CTX-M-13 and 1 CTX-M-3). TEM-1b spectrum β-lactamase was also prevalence in P. mirabilis. The diversity of β-lactamases in P. mirabilis and the emergency of multi-drug-resistance clinical strains will present serious threat to clinical therapy and even will lead to outbreak of nosocomial infections. Our study emphasizes the need for enhanced supervision of ESBL-producing P. mirabilis. Timely and reasonable drug-resistance data are indispensable to clinical therapy.

Antimicrobial Resistance,Virulence Profile,and Molecular Characterization of Listeria monocytogenes Isolated from Ready-to-eat Food in China,2013-2014

We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus

Seafood as a Reservoir of Gram-negative Bacteria Carrying Integrons and Antimicrobial Resistance Genes in Japan

PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from local and imported seafood samples collected from retail markets in Hiroshima Prefecture.Class 1 integrons containing gene cassettes encoding resistance to trimethoprim

Prevalence and antimicrobial resistance of non-typhoid Solmonella in military personnel,1988-2013

Objective:To describe the spanning 25 years data for the occurrence,magnitude,and trends regarding antimicrobial resistance of non-typhoidal Salmonella(NTS)isolated from non-immune travelers to Thailand participating in joint military operations.Methods:A total of 355 NTS isolates,obtained from 2052 fecal samples from US soldiers deployed for military maneuvers in Thailand during 1988-2013,were examined for NTS serogroup/serotypes and tested for antimicrobial susceptibility by disk diffusion to these 10 antibiotics:ampicillin,azithromycin(AZM),ciprofloxacin,colistin,gentamicin,kanamycin,nalidixic acid,streptomycin(STR),tetracycline(TET),and trimethoprim/sulfamethoxazole.Identified AZM-resistant NTS isolates were further evaluated for their minimal inhibitory concentration by the E-test method.Results:NTS infections accounted for 17.3%(355/2052),including11 serogroups and 50 different serotypes.The most prevalent serogroup was Salmonella group C2-C3(35.8%,127/355)followed by groups B(21.1%,75/355)and C1(18.6%,66/355).Identified serotypes included Salmonella hadar(n=60),Salmonella rissen(n=45),and Salmonella blockley(n=34).Among the predominate serogroups,antimicrobial resistance was consistently high against TET(76.9%,273/355)followed by STR(40.8%,145/355).One Salmonella senftenberg isolate demonstrated decreased ciprofloxacin susceptibility.Most isolates(94.6%)were resistant to one or more antimicrobials,and the most common multidrug resistance was TET-STR-nalidixic acid(11.5%,41/355).Conclusions:The prevalence of NTS serotypes and the growing magnitude of antibiotic resistant bacteria isolated from deployed US military in Thailand are documented from 1988-2013.This study demonstrates the antibiotic resistance profiles,highlighting the effectiveness of AZM that is a first-line treatment for travelers to Southeast Asia.AZM-resistant NTS isolates are periodically observed over a 25-year period.Hence,the ongoing surveillance and prevalence efforts are required to monitor NTS resistant strains causing further treatment failure.

Disease burden,antimicrobial resistance and molecular characterization of invasive group B Streptococcus among non-pregnant adults in Malaysia:A protocol study

and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance.

Antimicrobial Resistance Patterns and Bovine Sub-Clinical Mastitis Burden in Low and High Tick Acaricide Resistance Regions of Uganda

Mastitis, antimicrobial resistance and acaricide resistance pose significant threats to the development of the dairy industry in sub-Saharan Africa. This study aimed to determine the prevalence of antimicrobial resistance in bacteria isolated from CMT positive cows on farms located in high (HARA) and low (LARA) acaricide resistance challenge regions of Uganda. Among selected herds in both regions, subclinical mastitis (SCM) screening was performed using CMT. CMT positive samples were collected, cultured, bacteria isolated and antibiotic sensitivity tests conducted. Overall, the prevalence of SCM in cows was 71.5% and 27.7% for HARA and LARA respectively. A SCM herd prevalence of 66.3% and 28.2% was recorded for HARA and LARA respectively. Furthermore, 67.5% and 20.8% of the cows in the HARA and LARA groups, respectively, had three out of four udder quarters infected with SCM. Staphylococcus aureus (44.2%) and coagulase-negative Staphylococcus (CNS) (47.6%) were the most prevalent causative agents of SCM isolated from cows from HARA and LARA, respectively. Most isolates from both regions were highly resistant to penicillin (HARA, 84.3%;LARA, 95.6%) and colistin (HARA, 100%;LARA, 97.8%). Tetracycline (77.1%) and oxacillin (76.1%) resistance was high in isolates from HARA and LARA, respectively. Intermediate responses (neither susceptible nor resistant) to antibiotics were more common in isolates from HARA than in those from LARA. With this level of antibiotic resistance, there is a potential risk of failure to control mastitis in dairy cattle using antibiotics, especially in the HARA region, which may possibly jeopardize the growth of the dairy industry in Uganda.

Risk-Mitigation for Antimicrobial Resistance in Danish Swine Herds at a National Level

In Denmark, actions to mitigate the risk related to antimicrobial resistance have been put in place continuously. Due to an increase in the consumption of antimicrobials in the Danish pig production further actions were implemented in July 2010. These were： a voluntary ban on use of cephalosporin in Danish swine herds for a 2-year period and a so-called Yellow Card scheme from the DVFA （Danish Veterinary and Food Administration）. Farmers with the highest use of antibiotics receive a Yellow Card. In 2010, approximately 10% of Danish herds were above the Yellow Card threshold value. The consumption of antimicrobials in pigs is evaluated as ADD （animal daily doses） per 100 animals over the last 9 months （by age group）. Current permit limits for a Yellow Card in ADD/100 animal days are 5.2 （sows and piglets）, 28 （weaners）, and 8 （finishers）. In July 2010, farmers with an antimicrobial use close to these limits were warned by the DVFA, that unless actions were taken to reduce their antimicrobial use, they would receive a Yellow Card in December 2010. The means are, for instance, restrictions on oral medication usage and supervision from the authorities to which most expenses are to be covered by the farmer. The warning resulted in a decrease in the national consumption to pigs of 12.5% during the last half-year of 2010 compared to the same half-year in 2009. This decrease continued into 2011 where the consumption in January-February was 24.5% lower than for January-February 2010.

Antimicrobial Susceptibility and Genetic Basis of Resistance of <i>Klebsiella spp</i>Isolated from Diarrheic and Non-Diarrheic Children at Health Facilities in Mukuru Informal Settlement, Nairobi, Kenya

Antimicrobial resistance (AMR) is a global threat to public health and particularly to children. This study aimed to determine the prevalence of multidrug resistance of fecal Klebsiella spp on selected beta lactam (3rd generation cephalosporins and carbapenems) and fluoroquinolone classes of drugs in four health facilities serving the slum communities of Nairobi city in Kenya. Additionally, determine the genetic basis for the multidrug resistance observed. A cross sectional laboratory based study was undertaken where a total of 1171 children below 16 years were selected, from whom stool samples were collected, tested and analyzed. 395 (33.73%) Klebsiella spp were isolated, consisting of 365 (92.4%) Klebsiella pneumoniae and 30 (7.6%) Klebsiella oxytoca were isolated. The proportion of multi-drug resistance (MDR) K. pneumoniae and MDR K. oxytoca was 64.1% (234/365) and 96.67% (29/30) respectively. Third generation cephalosporins, cefotaxime ceftriaxone and ceftazidime showed the highest resistance of 30.7%, 29.9% and 27.4% respectively, whereas carbapenems including imipenem and meropenem had the least resistance of 1.6%, each, to K. pneumoniae. A significant association was observed in diarrheic children (OR = 1.88;p = 0.01) and those below 50 months (OR = 0.43;p = 0.002) and carrying K. pneumoniae resistance to one or more third generation cephalosporins. Genes associated with resistance included bla TEM 100%, bla CTX-M 95.2%, bla SHV 57.1%, bla OXA-1 66.7%, qnrS 54.1%, qnrB 47.6% and bla NDM 7.1%. In conclusion, there’s need for more effective infection control measures, antimicrobial stewardship to reduce emergence of antimicrobial resistance, improved drinking water, sanitation and hygiene (WASH) practices.

Prevalence of Antimicrobial Resistance of ESKAPE Pathogens before and during Pandemic COVID-19 Pandemic in a University Affiliated Hospital in Tangerang, Indonesia

Introduction: Antimicrobial resistance is the most important health problems currently. Antibiotic prophylaxis to prevent bacterial co-infections in hospitalized COVID-19 patients, and lack of surveillance were associated with antimicrobial resistance. ESKAPE pathogens consisting of E. faecium, S. aureus, K. pneumoniae, A. baumanii, P. aeruginosa and Enterobacter spp. are associated with healthcare-associated infections. Patients and Methods: This descriptive, retrospective, longitudinal study aims to describe the resistance rates of bloodstream infection due to ESKAPE pathogens from patients admitted in Siloam Hospital Karawaci, before and during COVID-19 pandemic (January 1st, 2019 until December 31st, 2022). Out of 296 ESKAPE pathogens collected from blood samples, S. aureus was the most frequent species, followed by K. pneumoniae, A. baumannii, P. aeruginosa, Enterobacter spp., and E. faecium. Results: Resistance rates of E. faecium were alarmingly high from 2019 until 2021, but in 2022 no sample was found. Resistance rates of S. aureus and MRSA decreased from 2019 until 2021 and then increased again in 2022 while for K. pneumoniae it peaked in 2020 and reached the lowest in 2022. Resistance pattern of A. baumanii was not favorable from 2019 until 2021, but decreased dramatically in 2022. Resistance pattern of P. aeruginosa was quite variable in 2021 and 2022 while for Enterobacter spp. it was variable in 2020 to 2022. Conclusion: The COVID-19 pandemic affected the antimicrobial resistance pattern of ESKAPE pathogens in Banten province, Indonesia. Resistance rates increased as the pandemic peaked in 2020 to 2021, and decreased as the pandemic resolves in 2022.

Antimicrobial Resistance and β-Lactamase Production among Hospital Dumpsite Isolates

Metallo-β-Lactamases (MBLs) and Extended Spectrum β-Lactamses (ESBLs) have emerged world-wide as a significant source of β-lactam resistance. The emergence of MBLs and ESBLs encoded on plasmids among Gram-negative pathogens in hospital dumpsites was investigated. Soils of different government and private hospitals were collected and processed following standard bacteriological techniques. Antimicrobial susceptibility testing was carried out by the disk-diffusion technique using Ceftazidime (30 μg), Cefuroxime (30 μg), Cefotaxime (30 μg), Cefixime (5 μg), Trimethprim-sulfamethoxazole (25 μg), Gentamycin (100 μg) Amoxicillin-Clavunalate (30 μg), Ciprofloxacin (5 μg), Ofloxacin (5 μg), Nitrofurantoin (300 μg) and Imipenem (10 μg). The role of plasmids in resistance was evaluated by subjecting isolates to curing using Sodium Dodecyl Sulfate (SDS). ESBLs production by Double-Disk Synergy Test (DDST) was carried out. Isolates resistant to Imipenem were subjected to a confirmatory test using Modified Hodge’s test and to MBLs production by DDST. Eighty-two Gram-negative isolates comprising of 32 (39.02%) Escherichia coli, 20 (24.39%) Serratia marcescens, 14 (17.07%) Klebsiella pneumonia, 10 (12.28%) Proteus mirabilis and 6 (7.32%) Enterobacter aerogenes were obtained. Susceptibility results revealed a 100% resistance of all isolates to Ceftazidime, Cefuroxime, Cefixime, Amoxycillin-clavulanate and Cefotaxime. A total of 66 (80.48%) isolates harboured plasmids out of which 26 (31.71%) isolates were ESBL producers. MBLs production was observed in 8 (25.00%) E. coli, 2 (2.41%) Klebsiella pneumonia and 2 (2.41%) Proteus mirabilis isolates. All MBLs producing isolates were ESBLs producers. The finding of highly resistant isolates producing ESBLs and MBLs in a hospital environment is quite disturbing and should be addressed urgently.

Expression of Exogenous Antimicrobial Peptide and Resistance to Stem Rot Disease of Houttuynia cordata Thunb.

[Objective] This study was to identify the expression of exogenous antimicrobial peptide in transgenic Houttuynia cordata Thunb. plants,and analyze their resistance to stem rot disease. [Methods] SDS-PAGE and Western blot analysis were employed to detect expression of exogenous antimicrobial peptide in transgenic H. cordata plants. Both wild type and transgenic H. cordata plants were inoculated with different concentrations of Rhizoctonia solani spores for detecting their resistance. [Results] The exogenous antimicrobial peptide was detected at translation level. The optimal parameters for detecting the resistance of transgenic H. cordata plants to R. solani was inoculation of spores at a concentration of 3×105 ind./ml and cultured for three days. The results showed that resistance of transgenic H. cordata plants to R. solani was enhanced in comparison with CKs. [Conclusion] Expression of exogenous antimicrobial peptide can enhance the resistance of transgenic H. cordata plants to stem rot disease.

Studies on Antimicrobial Resistance Transfer In vitro and Existent Selectivity of Avian Antimicrobial-Resistant Enterobacteriaccae In vivo

Increasing antimicrobial resistance （AR） has become a severe problem of public health in the world, whereas control of the AR of bacteria will be based on investigation of the AR mechanism. Furthermore, understanding the existent selectivity of AR organisms from animals can prevent the emergence and diffusion of AR effectively. PCR amplifications of gyrA and parC genes have been performed for detecting fluoroquinolones-resistance （FR） genes. A conjugational transfer test has been carried out using a donor which is resistant to tetracycline （TE）, ampicillin （AMP）, sulfamethoxazole-trimethoprim （SXT）, and a recipient which is sensitive to TE, AMP, and SXT. The AR strains have been passed 20 passages. Two groups of chicken inoculated multi-AR Escherichia coli （E. coli） and multi-AR Salmonella, respectively, are mix-fed. The result shows that amino acid codons of Ser-83 and Asp-87 are mutations from gyrA and there are no mutations from parC genes in all the FR strains. Resistance to TE, AM, and SXT can transfer among E. coli and the conjugal transfer frequency of TE is 3×10^-7. AR can inherit in 20 passages at least. The multi-AR E. coli and Salmonella can be isolated from all chickens three days after inoculation but CIP-resistant strains decrease during the time run out and disappear at 23 days after inoculation. The results indicate that the mutations of gene gyrA are correlative with the FR phenotype. AR genes that are not connected to the chromosome can transfer horizontally and vertically. AR bacteria can diffuse quickly and eliminate naturally from the host if the chicken is not under the pressure of this antibiotic.

Analysis of Multi-Drug Resistant Organism Surveillance and Antimicrobial Resistance Early Warning in a Hospital in 2022

Objective:To determine the clinical distribution of multi-drug resistant organism(MDRO)in Jiangyan Hospital and the monitoring and warning of drug-resistance bacteria to provide an important basis for guiding the application of broad-spectrum antibiotics in clinical treatment and reducing the occurrence of nosocomial infection.Methods:Retrospective screening and analysis were conducted on the pathogenic strains of hospitalized patients in our hospital in 2022.Results:A total of 2,769 strains of pathogenic bacteria and 390 strains of MDRO were detected and isolated in our hospital in 2022;the detection rate of MDRO was 14.08%.A total of 516 strains(18.64%)Klebsiella pneumoniae(KP)and 62 strains(12.02%)of carbapenem-resistant Klebsiella pneumoniae(CR-KP)were detected;436 strains(15.75%)of Escherichia coli(ECO)were detected,including 8 strains(1.83%)of CR-ECO;342 strains(12.35%)of Pseudomonas aeruginosa(PA)and 116 strains(33.92%)of CR-PA were detected;there were 194 strains(7.01%)of Acinetobacter baumannii(AB),among which 125 strains(64.43%)were CR-AB;there were 291 strains(10.51%)of Staphylococcus aureus,among which 79 strains(27.15%)of methicillin-resistant Staphylococcus aureus(MRSA)were detected;78 strains(2.82%)of Enterococcus faecalis were detected,and vancomycin-resistant enterococcus(VRE)was not detected.The first five MDROs were CR-AB,CR-PA,MRSA,CR-KP,and CR-ECO.The top five departments with the highest MDRO detection rate in 2022 were the ICU(37.44%),the Pulmonology Department(ward 13;31.03%),the Department of Rehabilitation(ward 5;6.67%),the Department of Neurosurgery(ward 11;4.62%),and the Department of General Surgery(ward 10;3.59 The resistance rate of antibacterial drugs is divided into four levels for early warning:30%to 40%,41%to 50%,51%to 75%,and 75%or more.Conclusion:Our hospital should strengthen the monitoring of antimicrobial resistance warning related to MDRO and the abuse of antimicrobial drugs.Based on the results of drug sensitivity and antimicrobial resistance warning,the use of antibiotics should be standardized in clinical practice to reduce nosocomial infection。

Pathogenicity and Antimicrobial Resistance in Coagulase-Negative Staphylococci

The coagulase-negative staphylococci (CoNS) group was considered saprophytic or rarely pathogenic for many years. Since the first case of septicemia caused by CoNS, there has been a progressive increase in the prevalence of healthcare-associated infections caused by CoNS. The CoNS group has emerged as one of the main causes of nosocomial infections related to vascular catheters and prostheses, especially among immunocompromised patients. This gradual increase in infections is due to the change in the relationship between patients and procedures since CoNS are closely related to devices implanted in the human body. CoNS are successful in colonizing the host because they have several virulence mechanisms, such as biofilm formation and production of enzymes and toxins, in addition to several mechanisms of resistance to antimicrobials. Despite their great clinical relevance, few studies have focused on CoNS’s pathogenicity and resistance to antimicrobials, which reveals the current need to better understand the factors by which this group became pathogenic to humans and other animals. This review aims to synthesize the aspects related to the pathogenicity and antimicrobial resistance in CoNS.

Beta-lactam antibiotic resistance among Escherichia coli isolates from patients with urinary tract infections in Vietnam:A systematic review and meta-analysis

Objective:To investigate the evolving patterns of antimicrobial resistance against beta-lactam antibiotics in Escherichia coli isolates from urinary tract infection patients in Vietnam,covering the period from 2005 to 2022.Methods:29 Descriptive studies published between 2010 and 2022 in English and Vietnamese were included in the analysis.Data on resistance rates to beta-lactam antibiotics,including cephalosporins and carbapenems,were extracted and analyzed.Weighted pooled resistance rates were calculated using random-effects models.Annual trends in resistance were assessed using linear regression analysis.Results:Among the beta-lactam antibiotics studied,Escherichia coli exhibited varying levels of resistance,with cephalosporins showing higher resistance rates compared to carbapenems.Weighted pooled resistance rates were 66%for cefotaxime,65%for ceftriaxone,54%for ceftazidime,and 56%for cefepime.In contrast,carbapenems demonstrated lower resistance rates,with weighted pooled resistance rates ranging from 3%to 4%for meropenem,ertapenem,and imipenem.Resistance rates were also observed for amoxicillin/clavulanate(35%),ticarcillin/clavulanate(26%),and piperacillin/tazobactam(12%).Significant annual increases in resistance were noted for imipenem(0.56%,P<0.001).Conclusions:This study highlights the critical issue of antimicrobial resistance in urinary tract infections in Vietnam and emphasizes the importance of prudent antibiotic use and the regular monitoring of resistance patterns.These insights are useful for guiding healthcare professionals in optimizing treatment strategies and for policymakers in formulating evidence-based clinical guidelines to combat antibiotic resistance effectively.