Evaluation Of Antimicrobial Resistance Research Articles

Comprehensive evaluation of clinical antimicrobial resistance using impedance-accelerated single-bacterium multiplex screening strategy

Rapid detection of bacterial antibiotic resistance is paramount in clinical settings to enable timely and effective therapeutic interventions. Traditional approaches such as disc diffusion and broth dilution are indeed dependable, however, they suffer from a notable drawback of long assay durations. This is attributed to the inherent delay caused by bacteria's macroscopic growth rate, which often necessitates measurement periods exceeding 20 hours, a timeframe incompatible with the clinical urgency. In this study, we demonstrate a comprehensive strategy on rapid bacterial antimicrobial resistance profiling and testing in clinical samples via a label-free impedance-accelerated single-bacterium screening. This system involves one newly developed parameter that is calculated from the two-dimensional kernel density values of different density regions in bacterial impedance spectra. By evaluating the changes in bacterial populations over a certain period using this new parameter, antimicrobial resistance of individual strains of bacteria can be determined within 20-minute antibiotics exposure. This high-throughput method rapidly and accurately determines the resistance profiles of five clinical Enterobacteriaceae strains against six antibiotic types. During the analysis of the impedance spectrum, we have also observed that antibiotics with different antimicrobial mechanisms have distinct effects on the bacterial impedance profile. This proposed method demonstrates excellent accuracy and rapid response time, providing a novel and practical strategy for next-generation antimicrobial susceptibility testing (AST) and antibiotic management.

Evaluation of Clinical Distribution and Antimicrobial Resistance of Klebsiella Pneumoniae

Purpose: This paper aims to analyze the clinical distribution and drug resistance changes of Klebsiella Pneumoniae (KPN) from 2017 to 2021 in the Beijing Hospital of Integrated Traditional Chinese and Western Medicine to provide a reference for the clinical rational use of antibiotics. Methods: We collected Klebsiella Pneumoniae isolated from various clinical specimens in 2017-2021, analyzed the isolation rate, specimen distribution, and department distribution characteristics during the five years, and statistically analyzed their drug sensitivity tests and multiple drug resistance. Zhuhai Deere DL-96 full-automatic microbial analyzer was used for bacterial identification and drug sensitivity tests. The drug sensitivity test was interpreted according to the standards recommended by the American Clinical and Laboratory Standards Institute (CLSI). Results: A total of 1057 strains of Klebsiella Pneumoniae were identified between 2017 and 2021, with proportions of 18.6%, 15.7%, 15.4%, 15.1%, and 15.0% in each respective year. Specimen distribution included sputum (66.0%), urine (17.9%), throat swab (9.4%), secretion (2.4%), pus (0.7%), venous blood (0.6%), vaginal swab (0.4%), and other sources (2.6%). Distribution by the department revealed specimens originating from the respiratory department (21.2%), cardiology department (17.8%), neurology department (13.4%), oncology department (13.0%), nephrology department (12.2%), acupuncture department (10.1%), and other departments (12.3%). In terms of drug susceptibility testing, Klebsiella Pneumoniae exhibited high resistance rates to ceftriaxone, cefotaxime, ceftazidime, and ampicillin/sulbactam, with rates of 50.8%, 46.8%, 46.3%, and 43.6% respectively. Conversely, resistance rates to minocycline, amikacin, imipenem, and meropenem were relatively low, at 8.6%, 16.5%, 8.5%, and 9.4% respectively. Resistance rates to cefepime/- sulbactam and piperacillin/tazobactam were 29.9% and 28.9%, respectively, while cephalosporin resistance rates ranged from 36.1% to 50.8%. Regarding multidrug resistance, the detection rates of ESBL-producing Klebsiella Pneumoniae were 8.2%, 10.9%, 4.5%, 10.6%, and 6.4% from 2017 to 2021, with an average detection rate of 7.9%. The detection rates of CR-Kp were 12.1%, 11.7%, 5.8%, 9.9%, and 8.9% respectively, averaging 9.6% over the five-year period. Conclusion: The sputum specimen of Klebsiella Pneumoniae exhibits the highest detection rate among specimen distributions, signifying its significance as a pathogenic bacterium in respiratory tract infections. Notably, the respiratory department demonstrates the highest detection rate, underscoring the necessity to enhance the monitoring and management of Klebsiella Pneumoniae infections in respiratory patients. Over the past five years, our hospital has observed a decreasing trend in the overall drug resistance rate of Klebsiella Pneumoniae to 17 antibiotics. While imipenem and meropenem exhibit minimal resistance rates, these carbapenem antibiotics serve as crucial agents for treating gram-negative bacilli, particularly in critically ill patients, and are thus not recommended as first-line choices for routine clinical use. Conversely, minocycline, amikacin, ceftazidime/ sulbactam, and piperacillin/tazobactam showcase relatively low resistance rates, enabling their empirical use based on clinical experience. Combination therapy with other antibiotics is advised for amikacin. Conclusion: Nevertheless, cephalosporins display a relatively high resistance rate, necessitating a reduction in their clinical utilization. Regarding multidrug resistance, the detection of ESBLs-producing Klebsiella Pneumoniae (KP) and Carbapenem-Resistant KP (CR-Kp) has exhibited a declining trend over the past three years. Despite this positive trend, the issue of multidrug resistance in Klebsiella Pneumoniae remains severe, with instances of complete drug resistance reported. Clinicians are urged to judiciously administer antibiotics guided by drug sensitivity test results and resistance rate variations, restrict the use of broad-spectrum antibiotics, and manage the emergence and spread of ESBLs-producing and CR-Kp bacteria.

Salmonella spp. in Domestic Ruminants, Evaluation of Antimicrobial Resistance Based on the One Health Approach-A Systematic Review and Meta-Analysis.

Salmonella spp. pose a global threat as a leading cause of foodborne illnesses, particularly prevalent in the European Union (EU), where it remains the second cause of foodborne outbreaks. The emergence of antimicrobial resistance (AMR) in Salmonella spp. has become a critical concern, complicating treatment strategies and escalating the risk of severe infections. The study focuses on large and small ruminants, identifying a prevalence of Salmonella spp. in slaughterhouses and revealing varied AMR rates across antimicrobial families throughout a meta-analysis. Also, comparison with AMR in human medicine was carried out by a systematic review. The results of the present meta-analysis displayed a prevalence of Salmonella spp. in large and small ruminants at slaughterhouses of 8.01% (8.31%, cattle; 7.04%, goats; 6.12%, sheep). According to the AMR of Salmonella spp., 20, 14, and 13 out of 62 antimicrobials studied were classified as low (<5%), high (>5% but <10%), and very high (>10%), respectively. Salmonella spp. did not display AMR against aztreonam, mezlocillin, ertapenem, meropenem, cefoxitin, ceftazidime, levofloxacin, tilmicosin, linezolid, fosfomycin, furazolidone, quinupristin, trimethoprim and spectinomycin. In contrast, a prevalence of 100% of AMR has been described against ofloxacin, lincomycin, and cloxacillin. In the context of the main antibiotics used in the treatment of human salmonellosis, azithromycin was shown to have the highest resistance among Salmonella spp. isolates from humans. Regarding cephalosporins, which are also used for the treatment of salmonellosis in humans, the prevalence of Salmonella spp. resistance to this class of antibiotics was similar in both human and animal samples. Concerning quinolones, despite a heightened resistance profile in Salmonella spp. isolates from ruminant samples, there appears to be no discernible compromise to the efficacy of salmonellosis treatment in humans since lower prevalences of AMR in Salmonella spp. isolated from human specimens were observed. Although the resistance of Salmonella spp. indicates some degree of concern, most antibiotics are not used in veterinary medicine. Thus, the contribution of cattle, sheep and goats to the rise of antibiotic resistance of Salmonella spp. and its potential impact on public health appears to be relatively insignificant, due to their low prevalence in carcasses and organs. Nevertheless, the observed low prevalence of Salmonella spp. in ruminants at slaughterhouse and the correspondingly low AMR rates of Salmonella spp. to key antibiotics employed in human medicine do not indicate that ruminant livestock poses a substantial public health risk concerning the transmission of AMR. Thus, the results observed in both the meta-analysis and systematic review suggests that AMR is not solely attributed to veterinary antibiotic use but is also influenced by factors such as animal health management (i.e., biosecurity measures, prophylactic schemes) and human medicine.

Molecular insights intoexpression and silencing of resistance determinants in Staphylococcus aureus.

This study aimed to investigate the status of antimicrobial-resistant strains of Staphylococcus aureus in Pakistan, their association in terms of co-occurrence with the biofilm-forming genes, resistance profiling and associated discrepancies in diagnostic methods. A total of 384 milk samples from bovine was collected by using convenient sampling technique and were initially screened for subclinical mastitis, further preceded by isolation and confirmation of S. aureus. The S. aureus isolates were subjected to evaluation of antimicrobial resistance by phenotypic identification using Kirby-Bauer disc diffusion method, while the genotypic estimation was done by polymerase chain reaction to declare isolates as methicillin, beta-lactam, vancomycin, tetracycline, and aminoglycoside resistant S. aureus (MRSA, BRSA, VRSA, TRSA, and ARSA), respectively. The current study revealed an overall prevalence of subclinical mastitis and S. aureus to be 59.11% and 46.69%, respectively. On a phenotypic basis, the prevalence of MRSA, BRSA, VRSA, TRSA, and ARSA was found to be 44.33%, 58.49%, 20.75%, 35.84%, and 30.18%, respectively. The results of PCR analysis showed that 46.80% of the tested isolates were declared as MRSA, 37.09% as BRSA, and 36.36% as VRSA, while the occurrence of TRSA and ARSA was observed in 26.31% and 18.75%, respectively. The current study also reported the existence of biofilm-producing genes (icaA and icaD) in 49.06% and 40.57% isolates, respectively. Lastly, this study also reported a high incidence of discrepancies for both genotypic and phenotypic identification methods of resistance evaluation, with the highest discrepancy ratio for the accA-aphD gene, followed by tetK, vanB, blaZ, and mecA genes. The study concluded that different antibiotic resistance strains of S. aureus are prevalent in study districts with high potential to transmit between human populations. The study also determined that there are multiple resistance determinants and mechanisms that are responsible for the silencing and expression of antibiotic resistance genes.

Analyzing resistome in soil and Human gut: a study on the characterization and risk evaluation of antimicrobial peptide resistance.

The limited existing knowledge regarding resistance to antimicrobial peptides (AMPs) is hindering their broad utilization. The aim of this study is to enhance the understanding of AMP resistance, a pivotal factor in the exploration of alternative drug development in response to the escalating challenge of antibiotic resistance. We utilized metagenomic functional selection to analyze genes resistant to AMPs, with a specific focus on the microbiota in soil and the human gut. Through a combination of experimental methods and bioinformatics analyses, our investigation delved into the possibilities of the evolution of resistance to AMPs, as well as the transfer or interchange of resistance genes among the environment, the human body, and pathogens. Additionally, we examined the cross-resistance between AMPs and evaluated interactions among AMPs and conventional antibiotics. The presence of AMP resistance, including various resistance mechanisms, was observed in both soil and the human gut microbiota, as indicated by our findings. Significantly, the study underscored the facile evolution of AMP resistance and the potential for gene sharing or exchange among different environments. Notably, cross-resistance among AMPs was identified as a phenomenon, while cross-resistance between AMPs and antibiotics was found to be relatively infrequent. The results of our study highlight the significance of taking a cautious stance when considering the extensive application of AMPs. It is imperative to thoroughly assess potential resistance risks, with a particular focus on the development of resistance to AMPs across diverse domains. A comprehensive grasp of these aspects is essential for making well-informed decisions and ensuring the responsible utilization of AMPs in the ongoing fight against antibiotic resistance.

Social and biological evaluation of antimicrobial resistance (SOBEAR) in rural India: a study protocol.

Antimicrobial resistance (AMR) has been one of the biggest global health threats in recent years, mostly in low- and middle-income countries, which requires urgent research using a multidisciplinary research approach. The use of large quantities of antimicrobial drugs inappropriately for humans, poultry and agriculture has been recognized as a leading cause of antibiotic resistance and the predominance of drug-resistance pathogens in the environment. This protocol aims to describe the use/misuse of antibiotics (ABs) in the community and evaluate clinical samples from healthcare settings to detect genes associated with antimicrobial resistance. We will conduct a community-level survey in different villages of the Tigiria block to assess knowledge and awareness on ABs and AMR. We will conduct in-depth interviews (IDIs) with doctors, pharmacists, nurses and drug sellers, as well as focus group discussions (FGDs) with ASHA and ANM workers who are involved in antibiotic supplies to the community. Quantitative data from the community survey and qualitative data of IDIs and FGDs will be linked and analyzed using statistical modeling and iterative thematic content analysis. Specimens (stool, urine, blood and wound/pus) will be collected from clinically diagnosed patients of different healthcare centers of Tigiria block. The samples will be cultured for bacterial isolation and antibiotic sensitivity testing. Genomic DNA will be isolated from positive bacterial cultures and sequenced using PCR to evaluate high-threat multi-drug resistance organisms (MDROs), screening of plasmid-mediated quinolone resistance (PMQR) genes, antimicrobial genes responsible for MDR and quinolone resistance-determining regions (QRDRs). This is the community-based protocol to evaluate the knowledge, attitudes, awareness and practices regarding ABs and AMR. The study protocol establishes a foundation for evaluating population-based prevalence and risk factors for AMR and MDROs in rural areas of the Odisha state, India.

Evaluation of frequency, antimicrobial resistance and multidrug resistance patterns of methicillin-resistant Staphylococcus aureus isolates at a university hospital in Northern Cyprus, 2016 to 2020

Evaluation of frequency, antimicrobial resistance and multidrug resistance patterns of methicillin-resistant Staphylococcus aureus isolates at a university hospital in Northern Cyprus, 2016 to 2020

Comparative evaluation of antimicrobial resistance among Enterobacteriaceae isolated from urine cultures in COVID-19 pre pandemic and pandemic period

NA

Economic evaluation of antimicrobial resistance in curable sexually transmitted infections; a systematic review and a case study.

To provide a summary of the economic and methodological evidence on capturing antimicrobial resistance (AMR) associated costs for curable sexually transmitted infections (STIs). To explore approaches for incorporating the cost of AMR within an economic model evaluating different treatment strategies for gonorrhoea, as a case study. A systematic review protocol was registered on PROSPERO (CRD42022298232). MEDLINE, EMBASE, CINAHL, Cochrane Library, International Health Technology Assessment Database, National Health Service Economic Evaluation Database, and EconLit databases were searched up to August 2022. Included studies were analysed, quality assessed and findings synthesised narratively. Additionally, an economic evaluation which incorporated AMR was undertaken using a decision tree model and primary data from a randomised clinical trial comparing gentamicin therapy with standard treatment (ceftriaxone). AMR was incorporated into the evaluation using three approaches-integrating the additional costs of treating resistant infections, conducting a threshold analysis, and accounting for the societal cost of resistance for the antibiotic consumed. Twelve studies were included in the systematic review with the majority focussed on AMR in gonorrhoea. The cost of ceftriaxone resistant gonorrhoea and the cost of ceftriaxone sparing strategies were significant and related to the direct medical costs from persistent gonorrhoea infections, sequelae of untreated infections, gonorrhoea attributable-HIV transmission and AMR testing. However, AMR definition, the collection and incorporation of AMR associated costs, and the perspectives adopted were inconsistent or limited. Using the review findings, different approaches were explored for incorporating AMR into an economic evaluation comparing gentamicin to ceftriaxone for gonorrhoea treatment. Although the initial analysis showed that ceftriaxone was the cheaper treatment, gentamicin became cost-neutral if the clinical efficacy of ceftriaxone reduced from 98% to 92%. By incorporating societal costs of antibiotic use, gentamicin became cost-neutral if the cost of ceftriaxone treatment increased from £4.60 to £8.44 per patient. Inclusion of AMR into economic evaluations may substantially influence estimates of cost-effectiveness and affect subsequent treatment recommendations for gonorrhoea and other STIs. However, robust data on the cost of AMR and a standardised approach for conducting economic evaluations for STI treatment which incorporate AMR are lacking, and requires further developmental research.

Antimicrobial Resistance Pattern and Empirical Antibiotic Treatments in Neonatal Sepsis: A Retrospective, Single-Center, 12-Year Study.

Neonatal sepsis is an important cause of morbidity and mortality in neonatal intensive care units (NICUs). Continuous evaluation of antimicrobial resistance (AMR) profiles is advised to implement antimicrobial stewardship (AMS) programs and establish effective empiric antibiotic protocols. AMS may reduce AMR in NICUs and improve sepsis outcomes. In this retrospective observational study, we report data on culture-positive neonatal sepsis, assessing differences after the implementation of an AMS program (2011-2016 vs. 2017-2022). A total of 215 positive bacterial cultures from 169 infants were retrieved, with 79 early-onset (36.7%) and 136 late-onset (63.3%) sepsis episodes. Frequent causative agents for early-onset sepsis were S. agalactiae and E. coli, all susceptible to empiric treatment. Late-onset sepsis was mainly caused by Enterobacterales and S. aureus. Aminoglycosides, cefotaxime, and piperacillin-tazobactam resistance among Enterobacterales was substantially low; S. aureus was mostly susceptible to oxacillin and vancomycin. There were no differences in mortality and multidrug-resistant pathogens rates between the two study periods. There were five episodes of fungal late-onset sepsis, mostly due to C. albicans, of which one was fatal. The microbial distribution pattern and AMR profiles overlapped with other European studies. Because susceptibility patterns are rapidly changing worldwide, with the emerging threat of Methicillin-resistant S. aureus and extended-spectrum beta-lactamases producers, infection prevention and control practices and AMS strategies require continuous optimization to limit selection pressure and AMR escalation.

Evaluation of antimicrobial resistance and risk factors for recovery of intrauterine Escherichia coli from cows with metritis on California commercial dairy farms

Metritis is a major uterine disease in dairy cattle, typically oc­curring within 21 days post-partum, and the fourth most com­mon health issue in cows as identified by producers. Currently, little is known of MICs of intrauterine E. coli (EC) to common antimicrobial drugs used to treat metritis in California dairies. The goals of this study were to evaluate factors affecting recov­ery and antimicrobial resistance (AMR) in intrauterine E. coli in post-partum dairy cows with and without metritis from com­mercial California dairy farms.

A Multicenter Evaluation of Overall Susceptibility and Antimicrobial Resistance Among Streptococcus pneumoniae Isolates.

S. pneumoniae ranks as the fourth-most lethal pathogen globally in terms of fatalities associated with or attributable to resistance. In this study, the Antimicrobial Testing Leadership and Surveillance (ATLAS) analysis from India aims to study the overall antimicrobial susceptibility (AMS) among pneumococcal isolates collected between 2018 and 2021. Non-duplicate clinically significant S. pneumoniae isolates were collected between 2018 and 2021. In vitro activity of antibiotics was assessed against S. pneumoniae. Susceptibility was confirmed at an International Health Management Associates (IHMA) laboratory using supplied broth microdilution panels (Omron Microscan Systems, Inc., Omron Corp., Kyoto, Japan), according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for all antibiotics. Of the total 86 non-duplicate isolates of Streptococcus pneumoniae collected from the tertiary care centers, the proportion of isolates increased from 8.14% (n=7) in 2018 to 43.02% (n=37) in 2020. Most isolates (n = 18; 48.65%) were collected from the age group of 31-60 years in the year 2020. Erythromycin revealed a decrease in susceptibility from the year 2018 (71.43%) to 2020 (16.22%). A decreased susceptibility of 90% was recorded for levofloxacin in the year 2021. Meropenem revealed a decrease in susceptibility from the year 2018 (85.71%) to 2020 (35.14%). Penicillin susceptibility decreased from 37.5% in 2019 to 27.03% in the year 2020. Clindamycin indicated a 100% susceptibility in the year 2018 which then decreased to 71.88% in 2019 and 56.76% in 2020. Linezolid and vancomycin were found to have uniform susceptibility of 100% throughout the years from 2018 to 2021. An increase in resistance to penicillin and macrolides among S. pneumoniae isolates was observed in the Indian population. Addressing the elevating rates of S. pneumoniae resistance may require pneumococcal conjugate vaccines (PCVs) with expanded serotype coverage and targeted antimicrobial stewardship efforts.

The epidemiology and microbiological characteristics of infections caused by Gram-negative bacteria in Qatar: national surveillance from the Study for Monitoring of Antimicrobial Resistance Trends (SMART): 2017 to 2019.

The global Study of Monitoring Antimicrobial Resistance Trends (SMART) is a surveillance program for evaluation of antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) from different regions including Gulf countries. To evaluate AMR in GNB from various clinical specimens including microbiological and genetic characteristics for existing and novel antimicrobials. A prospective study was conducted on clinical specimens from Hamad Medical Corporation, Qatar, between 2017 and 2019 according to the SMART protocol. Consecutive GNB from different sites were evaluated including lower respiratory, urinary tract, intrabdominal and bloodstream infections. Over the 3 years study period, 748 isolates were evaluated from the specified sites comprising 37 different GNB outlining four key pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia.For the two major pathogens E. coli and K. pneumoniae, phenotypic ESBL was identified in 55.77% (116/208) compared to 39% (73/187), while meropenem resistance was 3.8% compared to 12.8% and imipenem/relebactam resistance was 2.97% compared to 11.76%, respectively. The overall ceftolozane/tazobactam resistance for E. coli was 9.6% (20/208) compared to 14.97% (28/187) for K. pneumoniae while resistance for ceftazidime/avibactam was 3.65% (5/137) and 5.98% (10/117), respectively. Genomic characteristics of 70 Enterobacterales including 48 carbapenem-resistant, revealed prevalence of β-lactamases from all classes, predominated by blaCXM-15 while carbapenem resistance revealed paucity of blaKPC and dominance of blaOXA-48 and blaNDM resistance genes. Surveillance of GNB from Qatar showed prevalence of key pathogens similar to other regions but demonstrated significant resistance patterns to existing and novel antimicrobials with different underlying resistance mechanisms.

Evaluation of pathogen distribution and antimicrobial resistance in breast plastic surgery infection.

The demand for mammaplasty has increased in recent years, and infection remains one of the common and serious post-operative complications. In this study, we analyzed the pathogen distribution and antibiotic susceptibility of breast plastic surgery infections, and compared the differences in pathogenic species between surgical procedures. The number of each species was counted in the microbial samples of breast plastic surgery infections in Plastic Surgery Hospital of Chinese Academy of Medical Sciences from January 2011 to December 2021. The in vitro antibiotic sensitivity testing data were analyzed using WHONET 5.6 software. The surgical techniques, the period of infection, and other details were gathered in accordance with the clinical data. There were a total of 42 cases included, and 43 different types of pathogenic bacteria, mostly gram-positive bacteria, were found. CoNS (13/43) and Staphylococcus aureus (22/43) made up the majority. The most prevalent of the five Gram-negative bacteria was Pseudomonas aeruginosa. Results of drug sensitivity tests indicate that S. aureus is highly sensitive to vancomycin, cotrimoxazole, and linezolid, whereas CoNS is highly sensitive to vancomycin, linezolid, and chloramphenicol. Both of these bacteria show high resistance to erythromycin and penicillin. Breast augmentation, breast reconstruction, and breast reduction surgery were the most frequently associated breast surgery procedures in this study with infections, with the highest number of infections occurring following breast augmentation with fat grafting, breast reduction surgery, and breast reconstruction with autologous tissue. Various breast plastic surgery procedures have different common pathogens of infection, but the most prevalent are CoNS and S. aureus. Additionally, the majority of the infections in this study were in the early stages. Gram-positive bacteria were the predominant cause of breast plastic surgery infections, and the types of infection strains, the period of infection onset, and the antibiotic susceptibility of prevalent strains varied between breast plastic procedures.

Evaluation of Enterotoxins and Antimicrobial Resistance in Microorganisms Isolated from Raw Sheep Milk and Cheese: Ensuring the Microbiological Safety of These Products in Southern Brazil.

This study emphasizes the importance of monitoring the microbiological quality of animal products, such as raw sheep's milk and cheese, to ensure food safety. In Brazil, there is currently no legislation governing the quality of sheep's milk and its derivatives. Therefore, this study aimed to evaluate: (i) the hygienic-sanitary quality of raw sheep's milk and cheese produced in southern Brazil; (ii) the presence of enterotoxins and Staphylococcus spp. in these products; and (iii) the susceptibility of the isolated Staphylococcus spp. to antimicrobial drugs and the presence of resistance genes. A total of 35 samples of sheep's milk and cheese were examined. The microbiological quality and presence of enterotoxins were accessed using Petrifilm and VIDAS SET2 methods, respectively. Antimicrobial susceptibility tests were conducted using VITEK 2 equipment and the disc diffusion method. The presence of resistance genes tet(L), sul1, sul2, ermB, tetM, AAC(6)', tetW, and strA were evaluated through PCR. In total, 39 Staphylococcus spp. were obtained. The resistance genes tetM, ermB, strA, tetL, sul1, AAC(6)', and sul2 were detected in 82%, 59%, 36%, 28%, 23%, 3%, and 3% of isolates, respectively. The findings revealed that both raw sheep's milk and cheese contained Staphylococcus spp. that exhibited resistance to antimicrobial drugs and harbored resistance genes. These results underscore the immediate need for specific legislation in Brazil to regulate the production and sale of these products.

Evaluation of Virulence, Antimicrobial Resistance and Biofilm Forming Potential of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Bovine Suspected with Mastitis.

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen that poses a significant threat in cases of chronic mastitis in dairy animals. The ability of MRSA to persist in the host is attributed to various virulence factors, genes encoding surface adhesins, and determinants of antibiotic resistance, which provide it a survival advantage. This investigation focused to determine the virulence factors, antimicrobial resistance (AMR) profile and biofilm production potential of 46 MRSA isolates from 300 bovine mastitis milk samples. The AMR profile revealed a high level of resistance, with 46 and 42 isolates resistant to cefoxitin and oxacillin, respectively, followed by 24 and 12 isolates resistant to lomefloxacin and erythromycin, respectively. Only 2 isolates resistant to tetracycline and none were resistant to chloramphenicol. The study also evaluated various virulence factors such as coa (n = 46), nuc (n = 35) hlg (n = 36), pvl (n = 14), tsst-1(n = 28) spa (n = 39) and enterotoxin genes sea (n = 12) and seg (n = 28) and identified antibiotic resistance determinants mecA and blaZ in 46 and 27 isolates, respectively. Intercellular adhesion genes icaA and icaD were present in 40 and 43 isolates, respectively and surface adhesion genes ebps, fnbpA, eno, sasG, cna, and bap were found in 43, 40, 38, 26, 21 and 1 isolates, respectively. Microtiter plate (MTP) assay revealed that 29 MRSA isolates were capable of producing biofilms, whereas 17 were not. Biofilms producing MRSA isolates possessed adhesion genes, virulence factors, toxin genes and AMR genes that may act synergistically towards a chronic disease progression, illness and severe damage to the udder, which generally last for several months and very challenging to cure.

Antibiotic Resistance in Patients with Cystic Fibrosis: Past, Present, and Future.

Patients with cystic fibrosis (CF) are repeatedly exposed to antibiotics, especially during the pulmonary exacerbations of the disease. However, the available therapeutic strategies are frequently inadequate to eradicate the involved pathogens and most importantly, facilitate the development of antimicrobial resistance (AMR). The evaluation of AMR is demanding; conventional culture-based susceptibility-testing techniques cannot account for the lung microenvironment and/or the adaptive mechanisms developed by the pathogens, such as biofilm formation. Moreover, features linked to modified pharmaco-kinetics and pulmonary parenchyma penetration make the dosing of antibiotics even more challenging. In this review, we present the existing knowledge regarding AMR in CF, we shortly review the existing therapeutic strategies, and we discuss the future directions of antimicrobial stewardship. Due to the increasing difficulty in eradicating strains that develop AMR, the appropriate management should rely on targeting the underlying resistance mechanisms; thus, the interest in novel, molecular-based diagnostic tools, such as metagenomic sequencing and next-generation transcriptomics, has increased exponentially. Moreover, since the development of new antibiotics has a slow pace, the design of effective treatment strategies to eradicate persistent infections represents an urgency that requires consorted work. In this regard, both the management and monitoring of antibiotics usage are obligatory and more relevant than ever.

Evaluation of Antimicrobial Resistance of Different Phylogroups of Escherichia coli Isolates from Feces of Breeding and Laying Hens.

Animal and food sources are seen as a potential transmission pathway of multi-drug resistance (MDR) micro-organisms to humans. Escherichia. coli is frequently used as an indicator of fecal contamination in the food industry and known as a reservoir of antimicrobial resistance genes (ARGs). Microbial contamination as a major outcome for the poultry and egg industry and is a serious public health problem. In the present study we performed the quantification of β-glucoronidase positive E. coli in 60 fecal samples of breeding and laying hens collected in Portugal in 2019. Phylogenetic and pathotypic characterization, antimicrobial susceptibility, and detection of resistant extended-spectrum β-lactamase (ESBL) genes were assessed. The phylogenetic and pathogenic characterization and detection of ESBL genes were assessed by real-time PCR and antimicrobial susceptibility was evaluated using the disk diffusion method. Overall, E. coli quantification was 6.03 log CFU/g in breeding hens and 6.02 log CFU/g in laying hens. The most frequent phylogroups were B1. None of the isolates was classified as diarrheagenic E. coli (DEC). In total, 57% of the isolates showed MDR and 3.8% were positive for ESBL. Our study highlights that consumers may be exposed to MDR E. coli, presenting a major hazard to food safety and a risk to public health.

In Vitro Activity of Cefepime-Taniborbactam and Comparators against Clinical Isolates of Gram-Negative Bacilli from 2018 to 2020: Results from the Global Evaluation of Antimicrobial Resistance via Surveillance (GEARS) Program.

Taniborbactam is a novel cyclic boronate β-lactamase inhibitor in clinical development in combination with cefepime. We assessed the in vitro activity of cefepime-taniborbactam and comparators against a 2018-2020 collection of Enterobacterales (n = 13,731) and Pseudomonas aeruginosa (n = 4,619) isolates cultured from infected patients attending hospitals in 56 countries. MICs were determined by CLSI broth microdilution. Taniborbactam was tested at a fixed concentration of 4 μg/mL. Isolates with cefepime-taniborbactam MICs of ≥16 μg/mL underwent whole-genome sequencing. β-lactamase genes were identified in meropenem-resistant isolates by PCR/Sanger sequencing. Against Enterobacterales, taniborbactam reduced the cefepime MIC90 value by >64-fold (from >16 to 0.25 μg/mL). At ≤16 μg/mL, cefepime-taniborbactam inhibited 99.7% of all Enterobacterales isolates; >97% of isolates with multidrug-resistant (MDR) and ceftolozane-tazobactam-resistant phenotypes; ≥90% of isolates with meropenem-resistant, difficult-to-treat-resistant (DTR), meropenem-vaborbactam-resistant, and ceftazidime-avibactam-resistant phenotypes; 100% of VIM-positive, AmpC-positive, and KPC-positive isolates; 98.7% of extended-spectrum β-lactamase (ESBL)-positive; 98.8% of OXA-48-like-positive; and 84.6% of NDM-positive isolates. Against P. aeruginosa, taniborbactam reduced the cefepime MIC90 value by 4-fold (from 32 to 8 μg/mL). At ≤16 μg/mL, cefepime-taniborbactam inhibited 97.4% of all P. aeruginosa isolates; ≥85% of isolates with meropenem-resistant, MDR, and meropenem-vaborbactam-resistant phenotypes; >75% of isolates with DTR, ceftazidime-avibactam-resistant, and ceftolozane-tazobactam-resistant phenotypes; and 87.4% of VIM-positive isolates. Multiple potential mechanisms, including carriage of IMP, certain alterations in PBP3, permeability (porin) defects, and possibly, upregulation of efflux were present in most isolates with cefepime-taniborbactam MICs of ≥16 μg/mL. We conclude that cefepime-taniborbactam exhibited potent in vitro activity against Enterobacterales and P. aeruginosa and inhibited most carbapenem-resistant isolates, including those carrying serine carbapenemases or NDM/VIM metallo-β-lactamases (MBLs).

Evaluation of antimicrobial resistance among the clinically isolated S. aureus and E. coli from a hospital in Karachi, Pakistan

The surfacing and extend of antibiotic resistance in different organisms (parasites, fungi, bacteria, and virus) is among the mainly important health troubles of the world today. The battle to antimicrobial drugs has increased at society and mostly at hospital settings. Pan-resistant strains (organisms resistant to all antibiotics), multidrug-resistant (MDR), and extensively drug resistant (XDR) is antibiotic treatment decline and it has amplified morbidity, and mortality, along with important effects on the price of remedial treatment of bacterial infectious diseases. In this study antibiotic resistance of different groups of commonly used antibiotics has been studied for clinically isolated of S.aureus and E.coli grown by Blood, Urine, and Pus samples. All samples have been collected at Memon Medical Institute (MMI) Hospital, Karachi. Sixty-four clinical specimens were tested for their antibiogram pattern with broadly used antibiotics for the treatment of bacterial infections. Results indicated a range of 0 to 100% of antibiotic resistance showing a failure in antibiotic activity against E. coli and S.aureus. Piperacillin + Tazobactam (Ta), Cefoperazone + Sulbactum (Sul), Ciprofloxicin/Ofloxocin, Co-trimoxazole, and Aztreonam (Azactum) were 100% resistance by E.coli isolated from pus samples whereas, S.aureus showed resistance against Erythromycin 60% from pus, Ciprofloxicin/Ofloxocin57.14% from pus and urine, and Meropenem 57.14% from pus.