Enterococcal Isolates Research Articles

Analysis of Antibiotic-Resistant and Virulence Genes of Enterococcus Detected in Calf Colostrum-One Health Perspective.

Enterococci are considered among the most prevalent global multidrug-resistant microorganisms globally. Their dissemination is a global concern, particularly by food-producing animals for both animals and humans. The aim of this study was to identify the species and investigate the antibiotic resistance and virulence profile of Enterococcus in bovine colostrum. Out of 88 presumptive Enterococcus isolates, species identification and susceptibility to 14 antimicrobials were tested using the disk diffusion method. An analysis of the antibiotic resistance and virulence genes was performed on the most prevalent species, using specific PCR assays. Enterococcus faecalis (54.5%), E. faecium (14.8%) and E. gallinarum (6.8%) were the identified species. To the best of our knowledge, this is the first report of E. gallinarum in bovine colostrum. The majority of the isolates showed resistance to quinupristin-dalfopristin (95.9%), erythromycin (80.7%), tetracycline (80.7%) and streptomycin (58%). Ninety-two percent of isolates were classified as multidrug-resistant. The most frequently detected resistance genes were tet(K) (61.1%), tet(M) (75.9%), tet(L) (90.7%), erm(B) (55.6%) and ant(6)-Ia (46.3%). The most prevalent virulence factors were cpd, esp, agg and cylLL. Enterococcus faecium showed a higher probability of carrying the erm(C), tet(M), ace and gel(E) genes (p < 0.05). These results demonstrated that colostrum can constitute an important reservoir and vehicle for the dissemination of antibiotic resistance and virulence genes to the three niches included in a One Health perspective (humans, animals and the environment), highlighting the importance of hygiene sanitary measures to mitigate colostrum microbial contamination.

Targeted IS-element sequencing uncovers transposition dynamics during selective pressure in enterococci.

Insertion sequences (IS) are simple transposons implicated in the genome evolution of diverse pathogenic bacterial species. Enterococci have emerged as important human intestinal pathogens with newly adapted virulence potential and antibiotic resistance. These genetic features arose in tandem with large-scale genome evolution mediated by mobile elements. Pathoadaptation in enterococci is thought to be mediated in part by the IS element IS256 through gene inactivation and recombination events. However, the regulation of IS256 and the mechanisms controlling its activation are not well understood. Here, we adapt an IS256-specfic deep sequencing method to describe how chronic lytic phage infection drives widespread diversification of IS256 in E. faecalis and how antibiotic exposure is associated with IS256 diversification in E. faecium during a clinical human infection. We show through comparative genomics that IS256 is primarily found in hospital-adapted enterococcal isolates. Analyses of IS256 transposase gene levels reveal that IS256 mobility is regulated at the transcriptional level by multiple mechanisms in E. faecalis, indicating tight control of IS256 activation in the absence of selective pressure. Our findings reveal that stressors such as phages and antibiotic exposure drives rapid genome-scale transposition in the enterococci. IS256 diversification can therefore explain how selective pressures mediate evolution of the enterococcal genome, ultimately leading to the emergence of dominant nosocomial lineages that threaten human health.

Transmission of linezolid-resistant Enterococcus isolates carrying optrA and poxtA genes in slaughterhouses

IntroductionThe presence of linezolid-resistant enterococci found in animal-derived food has attracted attention for possible transmission to human-derived enterococci through the food chain. Linezolid-resistant enterococci in farms have been widely reported, but enterococci carrying antimicrobial resistance (AMR) genes poxtA, optrA, or cfr(D) in slaughterhouse environments have not been well addressed.MethodsEnterococcus was isolated from the samples collected from two slaughterhouses in Hangzhou, and the Enterococcus carrying linezolidin-resistant genes was identified by PCR. The minimum inhibitory concentration (MIC) of the Enterococcus carrying linezolidin-resistant genes was determined by microbroth dilution method. Finally, the whole genome of strains carrying two or more linezoline resistance genes was sequenced using the Oxford Nanopore TechnologyResultsHere, 291 enterococci strains were isolated from 309 samples (94.17%). A total of 4 poxtA-positive enterococci and 42 optrA-positive enterococci were identified based on PCR. The antimicrobial susceptibility test showed that the highest rate of florfenicol resistance was 97.82% and the rate of multidrug resistance (MDR) was 95.65%. Two strains carried multiple linezolid resistance genes, among which Enterococcus casseliflavus CQFYY22-063 cocarrying optrA, poxtA, and cfr(D) was isolated from the duck cecum, and Enterococcus faecium CQFYH22-006 cocarrying optrA and poxtA was isolated from slaughterhouse sewage for the first time. Furthermore, Oxford Nanopore Technology revealed that the optrA gene of strain CQFYY22-063 was located on the Inc18-type plasmid pFYY063-optrA-70K, and the poxtA and cfr(D) genes were located on the Inc18-type plasmid pFYY063- poxtA-12K. Meanwhile, the poxtA gene of strain CQFYH22-006 was located on the Rep3-type plasmid pFYH006-poxtA-25K, and the optrA gene was located on the chromosome.DiscussionTogether, linezolid resistance in slaughterhouses deserves extensive attention, indicating the need to strengthen the monitoring of different links in the food production chain within the One Health concept.

Virulence Factors of Clinical and Fecal Isolates of Enterococci Species

Enterococci species are known commensals of the gastrointestinal flora; however, in recent years, they have emerged as important nosocomial pathogens that possess many virulence factors that are attributed to the pathogenesis of diseases caused by them. The study evaluated and compared the virulence factors of Enterococci isolated from fecal and clinical samples. From the obtained isolates, the clinical enterococcal isolates produced 35%, 20%, and 50%, and fecal isolates produced 23%, 13%, and 13% gelatinase, hemolysin, and biofilm, respectively. Biofilm production determined by the Congo Red agar, tube, and microtiter plate methods was 23%, 39%, and 49%, respectively. The sensitivity of the Congo Red agar and tube method compared to the microtiter plate method was 27% and 46%, respectively, whereas the specificity of both tests was 79%. This study showed that biofilm production plays a significant role in the pathogenesis of diseases caused by Enterococci. Detection of biofilm production using the microtiter plate method is more sensitive and specific than the Congo Red agar and tube method.

Antibiotic Susceptibility Patterns and Virulence-Associated Factors of Vancomycin-Resistant Enterococcal Isolates from Tertiary Care Hospitals.

This study explored the prevalence of multi-drug resistance and virulence factors of enterococcal isolates obtained from various clinical specimens (n = 1575) including urine, blood, pus, tissue, catheter, vaginal wash, semen, and endotracheal secretions. Out of 862 enterococcal isolates, 388 (45%), 246 (29%), 120 (14%), and 108 (13%) were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Enterococcus hirae, respectively, using standard morphological and biochemical methods. The antibiotic resistance profile of all these enterococcal isolates was checked using the disc diffusion technique. High-level resistance was observed for benzylpenicillin (70%) and vancomycin (43%) among E. faecalis and E. faecium isolates, respectively. This study also revealed the prevalence of 'multi-drug resistance (resistant to 3 antibiotic groups)' among the vancomycin-resistant enterococcal strains, and this was about 11% (n = 91). The virulence determinants associated with vancomycin resistance (VR) were determined phenotypically and genotypically. About 70 and 39% of E. faecalis and E. faecium isolates showed to be positive for all four virulence factors (gelatinase, protease, hemolysin, and biofilm). Among the several virulence genes, gelE was the most common virulence gene with a prevalence rate of 76 and 69% among E. faecalis and E. faecium isolates, respectively. More than 50% of VRE isolates harbored other virulence genes, such esp, asa, ace, and cylA. Similarly, the majority of the VR enterococcal isolates (n = 88/91) harbored vanA gene and none of them harbored vanB gene. These results disclose the importance of VR E. faecalis and E. faecium and the associated virulence factors involved in the persistence of infections in clinical settings.

Antibiotic Resistance Pattern of Enterococci Isolates from Nosocomial Infections in Imam Khomeini Hospital, Ahvaz City

Introduction: Enterococci are opportunistic bacteria that can become pathogenic if colonized. Resistance to commonly used antibiotics by Enterococci causing nosocomial infections is of concern, which necessitates judicious, responsible and evidence-based use of antibiotics. The aim of this study was to evaluate the pattern of antibiotic resistance of Enterococci isolated from patients admitted to Imam Khomeini Hospital in Ahvaz City, Iran.&#x0D; Methods: The data of this cross-sectional description study were collected from October to March 2019 in the Microbiology Department of Imam Khomeini Hospital, Ahvaz City, Iran. Ninety samples of patients aged 1 to 99 years with infection caused by Enterococcus faecalis and Enterococcus faecium were included. The samples included urine culture, wound swab, vaginal swab, blood culture, catheter, sputum, broncho-aspirate, cerebrospinal fluid and other cases (abscess, drainage, ascites fluid, pleural fluid, culture fluid and purulent material). The antibiotic sensitivity of the isolates was measured using the agar disk diffusion method.&#x0D; Results: Enterococci were collected from 53 urine samples, 10 blood samples, 1 cerebrospinal fluid sample, 1 abscess sample, 2 cornea samples, 9 wound samples and 14 other secretion samples. The resistance of enterococcus strains against ciprofloxacin, ampicillin, imipenem and nalidixic acid was 66.7%, 42.6%, 55.6% and 93.3%, respectively. The highest sensitivity of Enterococcus isolates against ampicillin (42.6%) was observed. 43.3% of the samples obtained were from men and 56.7% from women.&#x0D; Conclusion: Based on the results of this study, a significant percentage of Enterococci strains are resistant to ciprofloxacin, imipenem, and nalidixic acid. Over-the-counter and unnecessary use of available antibiotics should be avoided to prevent increased resistance to common antibiotics.

Antibiotic Resistance of Enterococcus Species in Ornamental Animal Feed.

Enterococcus is a bacterial genus that is strongly associated with nosocomial infections and has a high capacity to transfer and acquire resistance genes. In this study, the main objective was to evaluate the presence of Enterococcus species in ornamental animal feed and characterize their antimicrobial resistance and virulence factors. Antimicrobial susceptibility was determined using 14 antimicrobial agents by the disk diffusion method, complemented by genotypic analysis to identify Enterococcus species and the presence of 14 antimicrobial resistance and 10 virulence genes. From 57 samples of ornamental animal feed, 103 Enterococcus isolates were recovered from 15 bird, 9 fish and 4 reptile feed samples. Enterococcus isolates were highly resistance to rifampicin (78%) and erythromycin (48%), and 48% of isolates were classified as multidrug-resistant. Enterococcus faecalis (36.7%) and E. faecium (31.7%) were the species most frequently identified. Most isolates carried the resistance genes ermB (57%) and tetL (52%) and the virulence genes, cylL (52%) and esp (40%). Enterococcus gallinarum was the species with the highest number of multidrug-resistant isolates (50%) and virulence genes (80%). These results highlight the high levels of antibiotic-resistant Enterococcus spp. present in ornamental animal feed and the growing interaction of these animals with humans as a public health concern.

The structure of ESKAPE pathogens isolated from patients of the neonatal intensive care unit at the National Hospital of Pediatrics in Hanoi, the Socialist Republic of Vietnam

Introduction. The incidence of healthcare-associated infections is a major public health problem worldwide, affecting all countries regardless of their economic status. The main agents of these infections are pathogens belonging to the ESKAPE group.&#x0D; The aim of the study was to explore the structure, molecular and antigenic characteristics of the ESKAPE pathogens isolated from oral and anal mucosa of patients of the neonatal intensive care unit (NICU), and to assess their etiological significance in occurrence of healthcare-associated infections.&#x0D; Materials and methods. Samples from a total of 49 children were tested, including 40 newborns patients of NICU at the National Hospital of Pediatrics in Hanoi. Collection and processing of biomaterial (oropharyngeal swabs, rectal swabs) and isolation of bacterial cultures were performed using conventional bacteriological methods. Mass spectrometry was used for identification of isolates. Klebsiella pneumoniae strains were analyzed using the whole-genome sequencing method.&#x0D; Results. The group of gram-positive ESKAPE pathogens identified in oral mucosa was represented by isolates Enterococcus faecium and Staphylococcus aureus. The isolates of the family Enterobacteriaceae included K. pneumoniae, Escherichia coli, Enterobacter cloacae; the group of nonfermenting gram-negative bacteria was represented by Pseudomonas aeruginosa, Acinetobacter baumannii. The structure of ESKAPE pathogens persistent in anal mucosa was characterized by dominance of Enterococcus spp., E. coli, K. pneumoniae and P. aeruginosa bacteria. The whole-genome sequencing of K. pneumoniae isolates revealed 7 clusters and 8 sequence types. ST14 and ST1741 prevailed, accounting for 25%, respectively, of the total number of the studied strains. The molecular serotyping showed that by the O antigen, strains belonged mainly to serotypes O1v1, O1/ O2v2, O5; by the presence of the capsular antigen to serotypes KL2, KL104, KL60.&#x0D; Conclusion. The analysis of the structure of the ESKAPE pathogens isolated from the oral and anal mucosa of patients of NICU at the National Hospital of Pediatrics in Hanoi identified etiologically significant agents of bacterial infections: S. aureus, K. pneumoniae, E. coli, E. cloacae, P. aeruginosa, A. baumannii. The molecular and genetic analysis of K. pneumoniae strains co-circulating in mucous membranes of several patients of the unit revealed their homology, thus confirming healthcare-associated contamination of children with nosocomial strains.

Ampicillin and Ceftobiprole Combination for the Treatment of Enterococcus faecalis Invasive Infections: "The Times They Are A-Changin".

Enterococcus faecalis is responsible for a large variety of severe infections. This study is a case series reporting our experience in the treatment of E. faecalis invasive infections with ampicillin in combination with ceftobiprole (ABPR). We retrospectively analyzed all the medical records of patients admitted to the University Hospital of Udine from January to December 2020 with a diagnosis of infective endocarditis or primary or non-primary complicated or uncomplicated bacteremia caused by E. faecalis. Twenty-one patients were included in the final analysis. The clinical success rate was very high, accounting for 81% of patients, and microbiological cure was obtained in 86% of patients. One relapse was recorded in one patient who did not adhere to the partial oral treatment prescribed. Therapeutic drug monitoring (TDM) was always performed for ampicillin and ceftobiprole, and serum concentrations of both drugs were compared to the MICs of the different enterococcal isolates. ABPR is a well-tolerated antimicrobial regimen with anti-E. faecalis activity. TDM can help clinicians optimize medical treatments to achieve the best possible efficacy with fewer side effects. ABPR might be a reasonable option for the treatment of severe invasive infections caused by E. faecalis due to the high level of enterococcal penicillin-binding protein (PBP) saturation.

SPECIATION AND ANTIMICROBIAL SUSCEPTIBILITY OF ENTEROCOCCI FROM PATIENTS IN A TERTIARY CARE HOSPITAL

Introduction: Enterococci have evolved from normal commensals to multidrug resistant pathogen. Enterococci are often reported in association with hospital-acquired infections. Management of Enterococcal infections has become challenging due to the emergence of multidrug resistant strains. Objectives: To speciate and detect the antibiotic susceptibility of Enterococci isolated from different clinical specimens.Materials and Methods: Atotal of 100 Enterococci strains isolated from clinical samples were tested using standard microbiological procedures. The minimum inhibitory concentration (MIC) for vancomycin was tested by agar dilution and E-strip methods. Results: Enterococci infections were more common in age groups, 21-40 years and 41-60 years with male preponderance. Isolates of Enterococci were more frequently associated with post operative wound infection (26%). E. faecalis (55%) was the predominant species, followed by E. faecium (45%). E. faecium showed 80% resistance to penicillin and ampicillin, while E. faecalis showed 38% resistance. All Enterococci isolates were 100% sensitive to vancomycin, linezolid and teicoplanin by the disc diffusion method; however, MIC for vancomycin by agar dilution and E-strip methods showed one strain of E. faecium resistant to vancomycin. Conclusion: Enterococci identication to the species level should be stressed in routine laboratory practice. Vancomycin resistance detection in Enterococci by the MIC method should be preferred as it helps reduce the morbidity and mortality due to Vancomycin resistant Enterococci.

VANCOMYCIN RESISTANT ENETROCOCCI- A STUDY ON PREVALENCEOF VANCOMYCIN RESISTANCE ENTEROCCI IN A TERTIARY CARE HOSPITAL IN SOUTH KERALA

Introduction: Vancomycin-resistant enterococci (VRE), are bacterial strains of the genus Enterococcus that are resistant to the antibiotic vancomycin. They have been associated with outbreaks of hospital-acquired (nosocomial) infections around the world. VRE can remain viable in the environment for an extended time period posing a problem for infection control in hospitals and nursing homes. They also pose a major therapeutic challenge as they possess intrinsic resistance to most of the commonly used antibiotics and can acquire resistance to most of the current available antibiotics. Assessment of the prevalence and changing trends of VRE infections is required to help plan infection control measures, which should be implemented in the hospital and also in the community to reduce the mortality and morbidity caused by these VRE infections. Objectives: This study was undertaken to determine the prevalence of Vancomycin resistance among Enterococcus species isolates obtained from clinical samples in a tertiary care hospital in southern India and also to detect resistant genes by molecular methods. A descriptive cross- Methods: sectional study was done on 150 non-duplicate isolates of Enterococcus species from different samples received at the Microbiology laboratory of Sree Gokulam Medical College and Research Foundation included consecutively from January 2021 to December 2021. Identication was based on Gram staining, colony morphologies, and biochemical tests. Antibiotic susceptibility testing was done by Kirby Bauer disc diffusion method on Mueller Hinton agar. Vancomycin resistance was determined by Vancomycin screen agar and vancomycin E -test method. Statistical Package for Social Sciences (SPSS) was used for preparing and analysis of data. Out of the Results: 150 Enterococcus species, 2% (3) isolates were resistant to Vancomycin by Vancomycin screen agar &amp; Vancomycin MIC test in which 2 were E. faecium and 1was E. faecalis. Out of 3 VRE, all were sensitive to Teicoplanin, so they were likely of vanB phenotype. Vancomycin resistant Enteroc Conclusion: occus species have emerged as important nosocomial pathogens in our institution with resistance of 2% per cent in our study. Increasing trend in the VRE rates, as seen in India and worldwide, need to be monitored and checked with active surveillance.

Aminopenicillins vs non-aminopenicillins for treatment of enterococcal lower urinary tract infections

Aminopenicillins (APs) achieve urinary concentrations that exceed typical minimum inhibitory concentrations for enterococcal lower urinary tract infection (UTI). The local clinical microbiology laboratory discontinued routine susceptibilities on enterococcal urine isolates, and reports that 'APs are predictably reliable for uncomplicated enterococcal UTI'. The objective of this study was to compare outcomes of APs with non-APs (NAPs) for enterococcal lower UTIs. This was an institutional-review-board-approved, retrospective cohort of adults hospitalized with symptomatic enterococcal lower UTIs from 2013 to 2021. The primary endpoint was composite clinical success at 14 days, defined as resolution of symptoms without new symptoms and no repeat culture growth of the index organism. A non-inferiority analysis was utilized with a 15% margin, and logistic regression evaluated characteristics associated with 14-day failure. In total, 178 subjects were included: 89 AP patients and 89 NAP patients. Vancomycin-resistant enterococci (VRE) were identified in 73 (82%) AP patients and 76 (85%) NAP patients (P=0.54); in total, 34 (38.2%) AP patients and 66 (74.2%) NAP patients had confirmed Enterococcus faecium (P<0.001). Amoxicillin (n=36, 40.5%) and ampicillin (n=36, 40.5%) were the most commonly used APs, and linezolid (n=41, 46%) and fosfomycin (n=30, 34%) were the most commonly used NAPs. Fourteen-day clinical success rates for APs and NAPs were 83.1% and 82.0%, respectively [1.1% difference, 97.5% confidence interval (CI) -0.117 to 0.139]. Among the E. faecium subgroup, 14-day clinical success was observed in 27/34 (79.4%) AP patients and 53/66 (80.3%) NAP patients (P=0.916). On logistic regression, APs were not associated with 14-day clinical failure (adjusted odds ratio 0.84, 95% CI 0.38-1.86). APs were non-inferior to NAPs for treating enterococcal lower UTIs, and may be considered irrespective of susceptibility results.

Assessment of antibiotic resistance and biofilm formation of Enterococcus species isolated from different pig farm environments in Poland

BackgroundEnteroccocus spp. are human opportunistic pathogens causing a variety of serious and life-threating infections in humans, including urinary tract infection, endocarditis, skin infection and bacteraemia. Farm animals and direct contact with them are important sources of Enterococcus faecalis (EFA) and Enterococcus faecium (EFM) infections among farmers, veterinarians and individuals working in breeding farms and abattoirs. The spread of antibiotic-resistant strains is one of the most serious public health concerns, as clinicians will be left without therapeutic options for the management of enterococcal infections. The aim of the study was to evaluate the occurrence and antimicrobial susceptibility of EFA and EFM strains isolated from a pig farm environment and to determine the biofilm formation ability of identified Enterococcus spp. strains.ResultsA total numer of 160 enterococcal isolates were obtained from 475 samples collected in total (33.7%). Among them, 110 of genetically different strains were identified and classified into EFA (82; 74.5%) and EFM (28; 25.5%). Genetic similarity analysis revealed the presence of 7 and 1 clusters among the EFA and EFM strains, respectively. The highest percentage of EFA strains (16; 19.5%) was resistant to high concentrations of gentamicin. Among the EFM strains, the most frequent strains were resistant to ampicillin and high concentrations of gentamicin (5 each; 17.9%). Six (7.3%) EFA and 4 (14.3%) EFM strains showed vancomycin resistance (VRE - Vancomycin-Resistant Enterococcus). Linezolid resistance was found in 2 strains of each species. The multiplex PCR analysis was performed to identify the vancomycin resistant enterococci. vanB, vanA and vanD genotypes were detected in 4, 1 and 1 EFA strains, respectively. Four EFA VRE-strains in total, 2 with the vanA and 2 with the vanB genotypes, were identified. The biofilm analysis revealed that all vancomycin-resistant E. faecalis and E. faecium strains demonstrated a higher biofilm-forming capacity, as compared to the susceptible strains. The lowest cell count (5.31 log CFU / cm2) was reisolated from the biofilm produced by the vancomycin-sensitive strain EFM 2. The highest level of re-isolated cells was observed for VRE EFA 25 and VRE EFM 7 strains, for which the number was 7 log CFU / cm2 and 6.75 log CFU / cm2, respectively.ConclusionsThe irrational use of antibiotics in agriculture and veterinary practice is considered to be one of the key reasons for the rapid spread of antibiotic resistance among microorganisms. Owing to the fact that piggery environment can be a reservoir of antimicrobial resistance and transmission route of antimicrobial resistance genes from commensal zoonotic bacteria to clinical strains, it is of a great importance to public health to monitor trends in this biological phenomenon.

Epidemiological characterization of the antimicrobial resistant Enterococcus isolates from four major rivers in South Korea

Epidemiological characterization of the antimicrobial resistant Enterococcus isolates from four major rivers in South Korea

Bacteriological study and its antibiotics susceptibility pattern of Otitis Media in Iraqi patients

Otitis media is an acute upper respiratory tract infection-related inflammation of the middle ear and tympanic membrane, frequently affecting children. Typically, a subsequent bacterial infection complicates a viral infection, which ultimately causes the condition. The study aims to study the function of bacterial ear infections and its causes, as well as their resistance to medications, which was the focus of this investigation. The first axis of the research was the identification of bacterial isolates using recognized diagnostic tools, and the second axis was determining the antibiotic's resistance and sensitivity. Patients with otitis media were gathered from Al-Hakim General Hospital and Al-Sadr city hospital in Al-Najaf city between November 2020 and April 2021 for 100 clinical samples. More than 80 samples were found to be infected with bacteria. Bacterial strains found in this investigation are ( 30 ) isolates of Pseudomonas aeruginosa, (20) isolates of Klebsiella spp, (20) isolates of Proteus spp, ( 15 ) isolates of Staphylococcus aureus, (8) isolates Escherichia coli and (7) isolates Enterococcus fecalies. As part of this research, the disk diffusion method was used to assess how sensitive the test was. The results showed that Pseudomonas aeruginosa was resistant to most antibiotics, particularly the penicillin family, cephalosporin, and trimethoprim, with the existence of isolates resistant to meropenem. The investigation results varied for the quinolone, aminoglycoside, and macrolide families. Klebsiella spp. were tested for antibiotic sensitivity and found to be resistant to most antibiotics, particularly those in the penicillin family, cephalosporins, and trimethoprim. Some quinolones, aminoglycosides, and macrolides are also resistant. Proteus spp were resistant to most antibiotics, particularly the penicillin family (except for augmentin, which had some sensitive isolates) and cephalosporin (except for cefdinir and cefepime) had some susceptible isolates) and trimethoprim, in addition to the presence of isolates resistant to meropenem. There is a discrepancy in the examination results for the quinolone family. The aminoglycoside family is also highly resistant. S. aureus isolates were resistant to penicillin (except for augmentin, which some isolates were responsive to), trimethoprim, and quinolones, with the presence of isolates resistant to vancomycin. The macrolide class ( azithromycin) also has a significant resistance level. Escherichia coli is susceptible to meropenem, imipenem, and certain cephalosporin generations. Augmentin, cefepime, cephalothin, meropenem, imipenem, and azithromycin were ineffective against Enterococcus fecal. The conclusion is that Pseudomonas spp has a role in ear infections and the germs Klebsiella spp., Proteus spp., Staphylococcus aureus, Escherichia coli, and Enterococcus fecalies. Penicillin and cephalosporin resistance was seen in the majority of the identified isolates. The existence of isolates of Proteus and Pseudomonas species resistant to meropenem. Vancomycin-resistant strains of Staphylococcus aureus isolates are present. Keywords: Otitis media, Resistance antibiotic, S.aureus, P.aerginosa

Vancomycin and Linezolid-Resistant Enterococcus Isolates from a Tertiary Care Center in India.

There is increasing development of antibiotic resistance among the Enterococcus species. This study was performed to determine prevalence and characterize the vancomycin-resistant and linezolid-resistant enterococcus isolates from a tertiary care center. Moreover, the antimicrobial susceptibility pattern of these isolates was also determined. A prospective study was performed in Medical College, Kolkata, India, over a period of two years (from January 2018 to December 2019). After obtaining clearance from the Institutional Ethics Committee, Enterococcus isolates from various samples were included in the present investigation. In addition to the various conventional biochemical tests, the VITEK 2 Compact system was used to identify the Enterococcus species. The isolates were tested for antimicrobial susceptibility to different antibiotics using the Kirby-Bauer disk diffusion method and VITEK 2 Compact to determine the minimum inhibitory concentration (MIC). The Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines were used to interpret susceptibility. Multiplex PCR was performed for genetic characterization of the vancomycin-resistant Enterococcus isolates and sequencing was performed for characterization of the linezolid-resistant Enterococcus isolates. During the period of two years, 371 isolates of Enterococcus spp. were obtained from 4934 clinical isolates showing a prevalence of 7.52%. Among these isolates, 239 (64.42%) were Enterococcus faecalis, 114 (30.72%) Enterococcus faecium, and others were Enterococcus durans, Enterococcus casseliflavus, Enterococcus gallinarum, and Enterococcus avium. Among these, 24 (6.47%) were VRE (Vancomycin-Resistant Enterococcus) of which 18 isolates were Van A type and six isolates of Enterococcus casseliflavus and Enterococcus gallinarum were resistant VanC type. There were two linezolid-resistant Enterococcus, and they were found to have the G2576T mutation. Among the 371 isolates, 252 (67.92%) were multi-drug resistant. This study found an increasing prevalence of vancomycin-resistant Enterococcus isolates. There is also an alarming prevalence of multidrug resistance among these isolates.

Temporal dynamics of the cecal and litter microbiome of chickens raised in two separate broiler houses.

In this study, we investigated the dynamics of the ceca and litter microbiome of chickens from post-hatch through pre-harvest. To achieve this, six hundred one-day old Cobb 500 broiler chicks were raised on floor pens for 49days in two separate houses. We performed short-read and full-length sequencing of the bacterial 16S rRNA gene present in the meconium and in cecal and litter samples collected over the duration of the study. In addition, we determined the antimicrobial resistance (AMR) phenotype of Escherichia coli and Enterococcus spp. isolated from the meconium and the ceca of 49-day old chickens. We monitored the relative humidity, temperature, and ammonia in each house daily and the pH and moisture of litter samples weekly. The overall microbial community structure of the ceca and litter consistently changed throughout the course of the grow-out and correlated with some of the environmental parameters measured (p < 0.05). We found that the ceca and litter microbiome were similar in the two houses at the beginning of the experiment, but over time, the microbial community separated and differed between the houses. When we compared the environmental parameters in the two houses, we found no significant differences in the first half of the growth cycle (day 0-21), but morning temperature, morning humidity, and ammonia significantly differed (p < 0.05) between the two houses from day 22-49. Lastly, the prevalence of AMR in cecal E. coli isolates differed from meconium isolates (p < 0.001), while the AMR phenotype of cecal Enterococcus isolates differed between houses (p < 0.05).

Clinical Resistant Strains of Enterococci and Their Correlation to Reduced Susceptibility to Biocides: Phenotypic and Genotypic Analysis of Macrolides, Lincosamides, and Streptogramins.

Enterococci are troublesome nosocomial, opportunistic Gram-positive cocci bacteria showing enhanced resistance to many commonly used antibiotics. This study aims to investigate the prevalence and genetic basis of antibiotic resistance to macrolides, lincosamides, and streptogramins (MLS) in Enterococci, as well as the correlation between MLS resistance and biocide resistance. From 913 clinical isolates collected from King Khalid Hospital, Hail, Saudi Arabia, 131 isolates were identified as Enterococci spp. The susceptibility of the clinical enterococcal isolates to several MLS antibiotics was determined, and the resistance phenotype was detected by the triple disk method. The MLS-involved resistance genes were screened in the resistant isolates. The current results showed high resistance rates to MLS antibiotics, and the constitutive resistance to all MLS (cMLS) was the most prevalent phenotype, observed in 76.8% of resistant isolates. By screening the MLS resistance-encoding genes in the resistant isolates, the erythromycin ribosome methylase (erm) genes that are responsible for methylation of bacterial 23S rRNA were the most detected genes, in particular, ermB. The ereA esterase-encoding gene was the most detected MLS modifying-encoding genes, more than lnuA (adenylation) and mphC (phosphorylation). The minimum inhibitory concentrations (MICs) of commonly used biocides were detected in resistant isolates and correlated with the MICs of MLS antibiotics. The present findings showed a significant correlation between MLS resistance and reduced susceptibility to biocides. In compliance with the high incidence of the efflux-encoding genes, especially mefA and mefE genes in the tolerant isolates with higher MICs to both MLS antibiotics and biocides, the efflux of resistant isolates was quantified, and there was a significant increase in the efflux of resistant isolates with higher MICs as compared to those with lower MICs. This could explain the crucial role of efflux in developing cross-resistance to both MLS antibiotics and biocides.

Prevalence of antimicrobial resistance in fecal Escherichia coli and Enterococcus spp. isolates from beef cow-calf operations in northern California and associations with farm practices.

Antimicrobials are necessary for the treatment of bacterial infections in animals, but increased antimicrobial resistance (AMR) is becoming a concern for veterinarians and livestock producers. This cross-sectional study was conducted on cow-calf operations in northern California to assess prevalence of AMR in Escherichia coli and Enterococcus spp. shed in feces of beef cattle of different life stages, breeds, and past antimicrobial exposures and to evaluate if any significant factors could be identified that are associated with AMR status of the isolates. A total of 244 E. coli and 238 Enterococcus isolates were obtained from cow and calf fecal samples, tested for susceptibility to 19 antimicrobials, and classified as resistant or non-susceptible to the antimicrobials for which breakpoints were available. For E. coli, percent of resistant isolates by antimicrobial were as follows: ampicillin 100% (244/244), sulfadimethoxine 25.4% (62/244), trimethoprim-sulfamethoxazole 4.9% (12/244), and ceftiofur 0.4% (1/244) while percent of non-susceptible isolates by antimicrobial were: tetracycline 13.1% (32/244), and florfenicol 19.3% (47/244). For Enterococcus spp., percent of resistant isolates by antimicrobial were as follows: ampicillin 0.4% (1/238) while percent of non-susceptible isolates by antimicrobial were tetracycline 12.6% (30/238) and penicillin 1.7% (4/238). No animal level or farm level management practices, including antimicrobial exposures, were significantly associated with differences in isolate resistant or non-susceptible status for either E. coli or Enterococcus isolates. This is contrary to the suggestion that administration of antibiotics is solely responsible for development of AMR in exposed bacteria and demonstrates that there are other factors involved, either not captured in this study or not currently well understood. In addition, the overall use of antimicrobials in this cow-calf study was lower than other sectors of the livestock industry. Limited information is available on cow-calf AMR from fecal bacteria, and the results of this study serve as a reference for future studies to support a better understanding and estimation of drivers and trends for AMR in cow-calf operations.

Isolation, screening and optimization of cellulase production by a novel bacterial isolate Enterococcus durans

Cellulose is an abundant plant biomass and a renewable source of energy in the ecosphere. The breakdown of cellulose occurs via the cellulase enzyme, which is commonly produced by microbes. This study aimed to optimize the fermentation parameters for enhanced cellulase production. Standardized parameters include isolation and screening of cellulase-producing bacteria (CPB), production of an enzyme, biochemical and molecular identification of bacterial isolate, optimization of cultural parameters, and application in wash performance. A total of 581 bacterial strains were isolated from soil samples, of which 16 isolates formed zones of hydrolysis on carboxymethylcellulose (CMC) agar media and were categorized as CPB. Based on maximum hydrolysis zone formation, three isolates, Krishi Vigyan Kendra-5 (KVK-5), Greenhouse-4 (GA-4), and Medicinal Garden-5 (MG-5) were chosen for bacterial cellulase production (BCP), with the isolate MG-5 proving to be the best cellulase producer (1.75 ± 0.01 U ml-1). Based on 16S rRNA gene sequencing the isolate MG-5 was identified as Enterococcus durans. The optimized parameters for the production of the cellulolytic enzyme were an incubation period of 48 h, CMC (carbon source), and yeast extract (nitrogen source) at a concentration of 1.5% w/v, pH 7, 45 °C, 1.5% v/v inoculum size and 100 rpm. Optimum conditions resulted in a 1.92-fold increase (3.36 U ml-1) in cellulase activity. Cellulase enzyme when used with detergent (Surf Excel), resulted in more efficient removal of chocolate stains on cotton fabric. This is the first report of Enterococcus durans producing cellulolytic enzymes. The analysis of cellulase in stain removal provides valuable evidence regarding the application of this enzyme in laundry cleaning.