Resistant Enterococci Research Articles

2473. Rates of Antibiotic Resistant Infections in Hospitalized Patients with Hematologic and Non-Hematologic Cancers, 2019

Abstract Background Patients with cancer have risk factors for developing both hospital-onset (HO) and antibiotic resistant (AR) infections such as high antibiotic use, long lengths of stay, and device utilization. Understanding the epidemiology of AR infections in this population can inform clinical management and prevention strategies. We aimed to describe the rates and proportions of AR infections in hospitalized patients with cancer. Methods Using the PINC AI Healthcare Database, we included adult discharges from 2019 among facilities reporting microbiology data. We identified patients with at least one cancer diagnosis from the Healthcare Cost and Utilization Project’s Clinical Classifications Software Refined categories and Elixhauser Comorbidity Software Refined for ICD-10-CM. We calculated age-standardized rates of AR infections among cancer patients per 10,000 discharges, stratified by community-onset (CO: ≤ day 3 of hospitalization) and HO (≥ day 4 of hospitalization), and hematologic and non-hematologic cancer types. Hematologic cancers included lymphoma, leukemia, myeloma and myelodysplastic syndrome. We also examined the proportion of AR infections in patients with cancer among all AR infections in the cohort. Results Of >2 million discharges from 277 facilities, 11.4% were patients with cancer. Compared to all patients, cancer patients had higher rates of infection with CO and HO vancomycin resistant Enterococcus (VRE) and carbapenem resistant Enterobacterales (CRE), and HO Enterobacterales with AR phenotypes suggestive of extended-spectrum β-lactamase (ESBL) production (Table 1). Compared to patients with non-hematologic cancer, patients with hematologic cancer had higher rates of all AR infections, except for CO carbapenem resistant Acinetobacter spp. (CRAsp) infections (Table 1). For most AR infections, cancer patients made up a greater proportion of all HO AR infections compared to CO AR infections (Table 2). Conclusion Patients with cancer had higher rates of several AR infections compared to all patients. To decrease the burden of AR infections in this population, infection prevention strategies may focus on VRE, ESBL, and CRE pathogens, as well as HO infections, in all cancer patients, particularly those with hematologic cancer. Disclosures All Authors: No reported disclosures

2402. Evaluating Clinical Outcomes of Adjunctive Beta-Lactam Use in Vancomycin-Resistant Enterococcus Infective Endocarditis

Abstract Background Vancomycin resistant enterococcus (VRE) infective endocarditis (IE) is associated with poor outcomes. There are limited data to guide the antimicrobial choice and duration of therapy. Several in vitro and limited clinical studies demonstrate the synergistic effect of β-lactams with other agents, particularly daptomycin, in this setting. We sought to compare clinical outcomes in patients with VRE IE treated with adjunctive β-lactam therapy. Methods This was an IRB-approved, retrospective, single-center cohort study. The study included patients ≥18 years of age diagnosed with VRE IE via modified Duke criteria from 2011-2021. Data were collected by electronic medical record review. Descriptive statistics were obtained. The primary outcome was 90-day treatment failure compared between those receiving and not receiving adjunctive β-lactams. Treatment failure was defined as recurrence of bloodstream infection (BSI) or death within 90 days of diagnosis. Failure-free survival was analyzed by Kaplan-Meier curve with log-rank test. Results A total of 32 cases were identified. 12 received adjunctive β-lactams. Mean age was 67 years, and 71% were male. 13 (41%) had a prosthetic valve and 6 (19%) had a CIED (Table 1). A majority (78%) had E. faecium IE. Mean duration of bacteremia was 9 days (Table 2). About one-third had treatment failure with 7 deaths and 4 BSI recurrences. Adjunctive β-lactams included ampicillin (3), cefepime (1), ceftaroline (6) and ceftriaxone (2). There was no statistical difference in failure-free survival in patients treated with adjunctive β-lactam therapy (Figure 1). The results were similar when restricted only to those who received daptomycin with or without adjunctive β-lactam therapy.Table 1.Patient CharacteristicsTable 2.Disease characteristics Figure 1. Kaplan-Meier curve comparing failure-free survival between patients who were primary treated with adjunctive β-lactams versus non-adjunctive therapy. The p-value is calculated via the log-rank test. Conclusion VRE IE is associated with poor prognosis, including high rates of mortality and relapses. In our experience, adjunctive B-lactam use did not result in improved outcome. Limitations include small sample size, and heterogenous antibiotic use. More prospective randomized data are needed. Disclosures All Authors: No reported disclosures

Antimicrobial Activity of Ceragenins against Vancomycin-Susceptible and -Resistant Enterococcus spp.

Ceragenins (CSAs) are a new class of antimicrobial agents designed to mimic the activities of endogenous antimicrobial peptides. In this study, the antibacterial activities of various ceragenins (CSA-13, CSA-44, CSA-90, CSA-131, CSA-138, CSA-142, and CSA-192), linezolid, and daptomycin were assessed against 50 non-repeated Enterococcus spp. (17 of them vancomycin-resistant Enterococcus-VRE) isolated from various clinical specimens. Among the ceragenins evaluated, the MIC50 and MIC90 values of CSA-44 and CSA-192 were the lowest (2 and 4 μg/mL, respectively), and further studies were continued with these two ceragenins. Potential interactions between CSA-44 or CSA-192 and linezolid were tested and synergistic interactions were seen with the CSA-192-linezolid combination against three Enterococcus spp., one of them VRE. The effects of CSA-44 and CSA-192 on the MIC values of vancomycin were also investigated, and the largest MIC change was seen in the vancomycin-CSA-192 combination. The in vivo effects of CSA-44 and CSA-192 were evaluated in a Caenorhabditis elegans model system. Compared to no treatment, increased survival was observed with C. elegans when treated with ceragenins. In conclusion, CSA-44 and CSA-192 appear to be good candidates (alone or in combination) for the treatment of enterococcal infections, including those from VRE.

The Synergistic Activity of Rhamnolipid Combined with Linezolid against Linezolid-Resistant Enterococcus faecium.

Enterococci resistance is increasing sharply, which poses a serious threat to public health. Rhamnolipids are a kind of amphiphilic compound used for its bioactivities, while the combination of nontraditional drugs to restore linezolid activity is an attractive strategy to treat infections caused by these pathogens. This study aimed to investigate the activity of linezolid in combination with the rhamnolipids against Enterococcus faecium. Here, we determined that the rhamnolipids could enhance the efficacy of linezolid against enterococci infections by a checkerboard MIC assay, a time-kill assay, a combined disk test, an anti-biofilm assay, molecular simulation dynamics, and mouse infection models. We identified that the combination of rhamnolipids and linezolid restored the linezolid sensitivity. Anti-biofilm experiments show that our new scheme can effectively inhibit biofilm generation. The mouse infection model demonstrated that the combination therapy significantly reduced the bacterial load in the feces, colons, and kidneys following subcutaneous administration. This study showed that rhamnolipids could play a synergistic role with linezolid against Enterococcus. Our combined agents could be appealing candidates for developing new combinatorial agents to restore antibiotic efficacy in the treatment of linezolid-resistant Enterococcus infections.

Vancomycin resistant enterococcus risk factors for hospital colonization in hematological patients: a matched case-control study

BackgroundVancomycin-resistant enterococcus (VRE) was the fastest growing pathogen in Europe in 2022 (+ 21%) but its clinical relevance is still unclear. We aim to identify risk factors for acquired VRE rectal colonization in hematological patients and evaluate the clinical impact of VRE colonization on subsequent infection, and 30- and 90-day overall mortality rates, compared to a matched control group.MethodsA retrospective, single center, case–control matched study (ratio 1:1) was conducted in a hematological department from January 2017 to December 2020. Case patients with nosocomial isolation of VRE from rectal swab screening (≥ 48 h) were matched to controls by age, sex, ethnicity, and hematologic disease. Univariate and multivariate logistic regression compared risk factors for colonization.ResultsA total of 83 cases were matched with 83 controls. Risk factors for VRE colonization were febrile neutropenia, bone marrow transplant, central venous catheter, bedsores, reduced mobility, altered bowel habits, cachexia, previous hospitalization and antibiotic treatments before and during hospitalization. VRE bacteraemia and Clostridioides difficile infection (CDI) occurred more frequently among cases without any impact on 30 and 90-days overall mortality. Vancomycin administration and altered bowel habits were the only independent risk factors for VRE colonization at multivariate analysis (OR: 3.53 and 3.1; respectively).ConclusionsAntimicrobial stewardship strategies to reduce inappropriate Gram-positive coverage in hematological patients is urgently required, as independent risk factors for VRE nosocomial colonization identified in this study include any use of vancomycin and altered bowel habits. VRE colonization and infection did not influence 30- and 90-day mortality. There was a strong correlation between CDI and VRE, which deserves further investigation to target new therapeutic approaches.

Detection of Biofilm Production and Antibiotic Resistance Pattern in Clinical Isolates from Orthopaedic Implants Associated Infections

Introduction: Orthopaedic Implant associated infection is the major problem which leads to implant failure and economic burden to the patient. Implant-associated infections are due to the formation of biofilm at the implantation site leading to multidrug resistant organism. Aim: This study was done to evaluate the causative organisms, their antibiotic sensitivity pattern and their ability to form biofilm over the Implants used in Orthopaedic surgeries. Material and methods: This study was carried out in the department of Microbiology, Adichunchanagiri institute of Medical sciences from September 2019 to August 2022. Swabs from 100 patients who had undergone orthopaedic implant or prosthetic surgery and presented with signs and symptoms of infection were collected and processed as per standard procedures. All the isolates were subjected to detect biofilm production by Congo red agar method, MRSA detection by Cefoxitin disc diffusion test, vancomycin resistant Enterococcus by using Vancomycin (Minimum inhibitory concentration) MIC strips and Extended spectrum β lactamases (ESBL) production by phenotypic confirmatory combined-disc test. Results: Out of the 100 samples processed, culture positivity was observed in 72 specimens. Among them, Staphylococcus aureus 19(26%) was the predominant isolate and 44 (61%) are biofilm producers. 17 (89%) were MRSA (Methicillin resistance Staphylococcus aureus) strains and 15(37%) were ESBL producing strains. Conclusion: The appropriate pre- and post- operative care should be taken to prevent orthopaedic implant associated infections. Staphylococcus spp was the commonest isolate and its ability to produce biofilm indicates the need for an appropriate antibiotic policy and screening for MRSA carriers to reduce the infection. Keywords: Orthopaedic implant, Infection, Biofilm, MRSA, ESBL

Evaluation of antibiotic susceptibility in enterococci isolated from blood culture samples

Aims: Increased vancomycin resistance in enterococci is an important cause of life-threatening bloodstream infections in hospitalized patients. The aim of this study is to determine the antibiotic susceptibility rates of Enterococcus strains isolated from blood cultures in hospitalized patients in Antalya Training and Research Hospital. 
 Methods: The antibiotic resistance rates of Enterococcus strains isolated from blood cultures of patients hospitalized in the service and intensive care units (ICU) between 1 January 2018 and 30 December 2022 were examined retrospectively. Blood samples were studied with the BacT/ALERT 3D culture system (Biomerieux, France). Bacterial identification was performed using conventional methods, Matrix Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometer (MALDI-TOF MS) and VITEK 2 (Biomerieux, France) systems. Antimicrobial susceptibility tests were performed with VITEK 2 (Biomerieux, France) systems. Ampicillin, vancomycin, teicoplanin, high-level gentamicin resistance (HLGR) and linezolid susceptibility of isolated strains were evaluated according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Vancomycin minimal inhibitory concentration (MIC) values of vancomycin resistant strains were studied by microdilution gradient strip test (Bioanalyse).
 Results: A total of 623 strains of enterococci were isolated from blood culture samples. Of the enterococci, 305 (48.9%) were identified as Enterococcus faecalis, 281 (45.6%) Enterococcus faecium, 12 (1.9%) Enterococcus avium, 11 (1.8%) Enterococcus gallinarum, 7 (1.2%) Enterococcus casseliflavus, 2 (0.4%) Enterococcus durans and 1 Enterococcus hirae (0.2%). Ampicillin and HLGR resistance rates of isolated E. faecalis strains were 11 (3.6%) and 72 (23.6%), respectively, and all strains were found to be susceptible to vancomycin, teicoplanin and linezolid. The ampicillin, vancomycin, teicoplanin and HLGR resistance rates of E. faecium strains were determined as 229 (81.5%), 36 (12.8%), 30 (10.7%) and 142 (50.5%), respectively, and all strains were found to be susceptible to linezolid. 
 Conclusion: In infections caused by enterococci, identification and determination of antibiotic susceptibility rates according to culture antibiogram results would be the right approach. Knowing the current susceptibility rates of enterococci isolated from blood culture samples in our hospital will contribute for clinicians' planning of empirical treatment.

Multidrug Resistance in Enterococci Isolated from Cheese and Capable of Producing Benzalkonium Chloride-Resistant Biofilms.

This study aimed to investigate enterococci recovered from eight Portuguese cheeses made with raw ewe's milk, regarding antibiotic resistance, virulence genes, minimum inhibitory concentration (MIC) of benzalkonium chloride (BAC), biofilm formation capacity, and biofilm eradication (MBEC) by BAC. Antimicrobial resistance against seven antibiotics of five groups was evaluated using the disk diffusion method. The presence of the genes that encode resistance to the antibiotics penicillin (blaZ), erythromycin (ermA, ermB, and ermC), vancomycin (vanA and vanB), aminoglycoside (aac(6')-Ie-aph(2″)-Ia), and β-lactam (pbp5) and the genes that encode virulence factors, frsB, cylA, gelE, esp, and agg, were investigated via multiplex PCR. The susceptibility of planktonic cells to BAC was evaluated by the MIC and MBC values of the isolates, using the broth microdilution method. To assess the biofilm-forming ability and resistance of biofilms to BAC, biofilms were produced on stainless steel coupons, followed by exposure to BAC. The results showed a high resistance to the antibiotics vancomycin (87.5%), erythromycin (75%), tetracycline (50%), and penicillin (37.5%). Multidrug resistance was observed in 68.8% of the isolates. Genes encoding the virulence factors FrsB (frsB) and gelatinase E (gelE) were detected in all isolates. The esp and cylA genes were found in 56.3% and 37.5% of the isolates, respectively. All isolates exhibited a biofilm-forming ability, regardless of incubation time and temperature tested. However, after 72 h at 37 °C, E. faecium and E. faecalis biofilms showed significant differences (p ≤ 0.05). Although most isolates (62.5%) were susceptible to BAC (MIC ≤ 10 mg/L), biofilms of the same isolates were, generally, resistant to the higher concentration of BAC (80 mg/mL) tested. This study using Enterococcus isolates from a ready-to-eat food, such as cheese, reveals the high percentages of vancomycin resistance and multidrug resistance, associated with the presence of virulence genes, in isolates also capable of producing biofilms resistant to BAC, an important active ingredient of many disinfectants. These results emphasize the need for effective control measures to ensure the safety and quality of dairy products.

First report of vancomycin resistant Enterococcus faecalis and Enterococcus faecium isolated from water buffalo clotted cream in Turkey

This study aimed to isolate the Enterococcus species from homemade water buffalo clotted cream sold in Afyonkarahisar, investigate the vancomycin resistance genes in isolated strains by PCR and determine the antibiotic resistance of strains to some antibiotics commonly used in Turkey. A total of 107 buffalo clotted cream samples sold in public bazaars of Afyonkarahisar were collected. Following the phenotypic identification using a commercial identification kit, PCR was applied to strains using by species specific primers. Forty Enterococcus strains were obtained from 107 samples by PCR. Of 40 strains, 31 (77.5%) and 9 (22.5%) were identified to be E. faecalis and E. faecium, respectively. One vanA (2.5%) and 14 vanB (35%) genes were determined in tested 40 strains. While of strains having the vanB gen, 10 and four were found to be E. faecalis and E. faecium, respectively, one E. faecium strain also harboured the vanA gen. Thus, while the vanB gen positivity was found to be 32.3% in 31 E. faecalis strains and 44.4% in 9 E. faecium strains, the vanA gen positivity was determined to be 11.1% in 9 E. faecium strains. It was not found the vanC1 and vanC2/C3 genes in none of the strains. While all of strains were phenotypically resistant to streptomycin and fusidic acid, high resistance rates were also determined in the strains to kanamycin (87.5%), cephalothin (80%), erythromycin (80%), gentamicin (77.5%), tetracycline (75%) and vancomycin (60%). Resistance to all tested antibiotics except teicoplanin was determined in E. faecalis strains and except chloramphenicol in E. faecium strains harbouring the vancomycin resistance genes. In conclusion, it was thought the buffalo clotted creams offered for consumption in Afyonkarahisar may have potential risk for public health in terms of VRE species. To our knowledge, this is the first study showing the presence of VRE in the clotted cream samples by PCR in Turkey.

Early-life antibiotic usage and impact on the gut microbiota, including emergence of antimicrobial resistant Enterococcus

The early-life microbiota is an ‘immature’ and highly dynamic microbial ecosystem, which is central to infant health. Both perinatal and postnatal factors can impact the gut microbiota, with antibiotics proposed to cause short and longer-term disturbances. Antibiotics not only impact microbial community composition but also contribute to the overall antibiotic resistance profile, i.e. the ‘resistome’, and they may also enhance carriage of multi-drug-resistant bacteria. Given high antibiotic prescription practices in pregnant women and newborns this also contributes to the global threat of antimicrobial resistance. This review summarises the current literature on antibiotic usage and how this may impact the developing gut microbiota during early-life, including the influence of horizontal gene transfer on contributions to pathogenicity and resistance of gut bacteria. We also focus on Enterococcus spp. given their high levels in infants and their link with opportunistic infections that are a significant cause of morbidity and mortality during early-life. Finally, a perspective on the importance to antibiotic stewardship, and harnessing the microbiota itself for anti-infection therapies for reducing antibiotic usage are also covered.

Isolation and characterization of multi-drug resistant Enterococcus faecalis as a causative agent of dental abscessesand infections in Egyptian patients

Isolation and characterization of multi-drug resistant Enterococcus faecalis as a causative agent of dental abscessesand infections in Egyptian patients

Important Features for Protein Foldings in Two Acyl Carrier Proteins from Enterococcus faecalis.

The emergence of multi-drug resistant Enterococcus faecalis raises a serious threat to global public health. E. faecalis is a gram-positive intestinal commensal bacterium found in humans. E. faecalis can endure extreme environments such as high temperature, pressure, and high salt, which facilitates them to cause infection in hospitals. E. faecalis has two acyl carrier proteins, AcpA (EfAcpA) in de novo fatty acid synthesis (FAS) and AcpB (EfAcpB) which utilizes exogenous fatty acids. Previously, we determined the tertiary structures of these two ACPs and investigated their structure-function relationships. Solution structures revealed that overall folding of these two ACPs is similar to those of other bacterial ACPs. However, circular dichroism (CD) experiments showed that the melting temperature of EfAcpA is 76.3°C and that of EfAcpB is 79.2°C, which are much higher than those of other bacterial ACPs. In this study, to understand the origin of their structural stabilities, we verified the important residues for stable folding of these two ACPs by monitoring thermal and chemical denaturation. Hydrogen/deuterium exchange and chemical denaturation experiments on wild-type and mutant proteins revealed that Ile10 of EfAcpA and Ile14 of EfAcpB mediate compact intramolecular packing and promote high thermostability and stable folding. E. faecalis may maximize efficiency of FAS and increase adaptability to the environmental stress by having two thermostable ACPs. This study may provide insight into bacterial adaptability and development of antibiotics against multi-drug-resistant E. faecalis.

Identification of Vancomycin Resistant Enterococcus Genes in Clinical Isolates

Vancomycin resistant enterococci (VRE) nosocomial diseases are rapidly spreading across the world. To treat these diseases is becoming a great challenge due to antibiotic resistance. The present study was aimed to estimate the prevalence of vancomycin resistant enterococci and to find out genes responsible for causing vancomycin resistance. One hundred different blood, wound and urine samples were collected from hospitalized patients at tertiary care health hospital, Lahore. On the basis of colony morphology, isolates of Enterococci were identified, Gram staining and biochemical tests including catalase test, Bile esculin test, growth in 6.5% NaCl, litmus milk reduction were performed. All the clinical isolates were checked for vancomycin resistant and 15% of all the samples were vancomycin resistant. Polymerase chain reaction (PCR) was performed for vancomycin resistance, enterococcal isolates to identify van genes responsible for resistance. In our study the presence of vanA gene was found in all 15 vancomycin resistant samples. vanB gene was not detected in any of the sample. The study highlights the increased VRE prevalence in clinicalisolates obtained from local hospital. The presence of vanA gene in all resistant samples is suggestive of its role as resistant gene. On the basis of these results there is an urgent need of establishing a rational antibiotic use policy for better management of enterococcal infections.

Purification and biological analysis of antimicrobial compound produced by an endophytic Streptomyces sp.

Fungal phytopathogens and drug-resistant bacteria are two significant challenges in agriculture and public health, respectively. As a result, new sources of antimicrobial compounds are urgently needed. Taking into consideration these aspects, the present study was carried out to explore the antimicrobial activity of Streptomyces sp. SP5 against drug-resistant bacteria, especially methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus and fungal phytopathogens. MRSA and VRE are both types of antibiotic-resistant bacteria that pose significant challenges to public health. In vitro analysis of the metabolites of Streptomyces sp. SP5 exhibited broad-spectrum antimicrobial activity against drug-resistant bacteria and phytopathogenic fungi. Further chemical investigation of the diethyl ether extract led to the isolation and purification of an antimicrobial compound. The structure of the purified compound was elucidated by performing detailed spectroscopic analysis including MS, IR, and NMR. The compound was identified as plicacetin. Plicacetin is a nucleoside antibiotic that has been reported for antibacterial activity against Gram-positive bacterium Mycobacterium tuberculosis. According to our knowledge, the present study is the first to demonstrate the antimicrobial properties of plicacetin against Fusarium oxysporum, Alternaria brassicicola, Fusarium solani, VRE and Bacillus subtilis. The outcome of the current study endorses that compound produced by Streptomyces sp. SP5 can be used as an antimicrobial agent against fungal phytopathogens and drug-resistant bacteria.

Antimicrobial Resistance of the Genus Enterococcus in Cantonal Hospital of Zenica, Bosnia and Herzegovina

Among Enterococcus spp, only the virulence gene harboring strains of Enterococcus faecalis and E. faecium are associated with human infections, including urinary tract infections (UTI), pelvic, blood, intraabdominal, and skin and soft tissue infections (SSTI). Over the past decades, enterococcal antimicrobial resistance has escalated in many regions of the world, leading to ominous outcomes. The rising incidence of Healthcare-Associated Infections (HCAIs) secondary to Vancomycin-resistant strain (VRE) resulted in high morbidity and mortality, as well as substantial challenges in control, prevention, and management). The aim of this study is to examine the antimicrobial resistance of E. faecalis and E. faecium species in different human samples. The study included 184 clinical samples over a period of 6 months. E. faecalis was identified in 95.65% and E. faecium in 4.35% of cases. E. faecalis isolates showed resistance to gentamicin in 40.9% of cases and to ampicillin in 1.7% of cases. Resistance to nitrofurantoin and ciprofloxacin was observed in 6.1% and 35.7% of E. faecalis isolates. VRE was isolated in 1.1% of E. faecalis isolates tested for this antibiotic. Resistance of E. faecium isolates to ampicillin and gentamicin was observed in 87.5% of cases in both antibiotics. All urinary isolates of E. faecium were resistant to ciprofloxacin. All E. faecium isolates were sensitive to vancomycin. Based on the results of our study, the growing importance of Enterococcus spp. as a causative agent of hospital infections and infections in the general population, and its antimicrobial resistance to various drugs were observed.

Status of Biofilm Production and Vancomycin Resistance in Enterococcus in the Rural Population of Mathura, India.

Introduction Hospital-acquired or nosocomial infections caused by the rapidly emerging bacteria vancomycin-resistant enterococci can be dangerous and even fatal. Therefore, this study aimed to investigate the presence of enterococci in various clinical specimens along with their vancomycin resistance status and biofilm-producing capabilities. Methods A total of 164 Enterococcus species were isolated and further included in this study. Isolation and identification were done by the standard bacteriological procedure, antibiotic susceptibility testingwas done by clinical laboratory standard guidelines, and biofilm production test was done by microtiter plate methods. Results Among the total of 164 isolates, Enterococcus faecalis constituted 60.97% and Enterococcus faecium constituted 39.02%. Maximum isolates were from urine samples. The prevalence of vancomycin-resistant Enterococcus was 6.70%, and 18.29% of Enterococcus isolates were biofilm producers. The sensitivity among the biofilm producers was maximum for linezolid (87.33%), followed by teicoplanin (86.43%) and vancomycin (79.64%). Conclusion High prevalence of enterococci was found in urine samples andbiofilm producers Enterococcus isolates were more antibiotic-resistant than non-biofilm producers.

Antibiotic Resistance and Susceptibility Profile, with Biofilm Forming Potential Of Clinically Isolated Enterococcus Specie from Blood and Urine Samples

Enterococcus spp. is Gram-positive cocci bacteria among the normal flora in human intestine. Common species are Enterococcus fecalis and Enterococcus faecium. They work as probiotics and help in digestion and immune system modulation. Enterococci are opportunistic pathogens and can cause nosocomial infections. Biofilm is one of the factors that facilitate the antibiotic resistance, which is complex EPS (exopolysaccharides) structure surrounding microbial cells, making them resistant from antimicrobial treatments. Due to acquisition of different virulence factors and resistance from antibiotics, infections of Enterococcus spp., have increased. In this study antibiotic resistance and sensitivity profile with their ability to form biofilm, has been determined. Human blood and urine samples were taken from Memon Medical Hospital Karachi. Culture and sensitivity test was performed for the major groups of antibiotics used for treating enterococcal infections with analysis of biofilm formation. Highest resistance was observed against the antibiotic levofloxacin 90% and all organisms were sensitive from linezolid 100%. Overall organisms were resistance from one and more antibiotics. All organisms were able to form biofilms as well. Antibiotic resistance has become an alarming challenge for the health care globally. Enterococcal resistance from major groups of antibiotics for their treatment has increased the rate of nosocomial infections.

The Emergence of Antimicrobial Resistance and Virulence Characteristics in Enterococcus Species Isolated from Bovine Milk.

Enterococcus spp., including E. faecalis and E. faecium, pose risks to dairy farms as opportunistic pathogens. The study evaluates antimicrobial resistance (AMR) and virulence characteristics of Enterococcus spp. isolated from bovine milk. Bile esculin agar was used to assess 1471 milk samples, followed by colony identification, gram staining, catalase tests, and 45 °C incubation. PCR analysis targeted E. faecalis and E. faecium in characteristic Enterococcus spp. colonies, with MALDI-TOF used for negative samples. Multiple tests, including disk diffusion, chromogenic VRE agar for vancomycin resistance, Vancomycin Etest® for MIC determination, and PCR for virulence factors (cylA, esp, efaA, ace, asa1, gelE, and hyl genes), were performed. Out of 100 identified strains, E. durans (30.66%), E. faecium (26.28%), and E. faecalis (18.25%) were predominant. AMR in Enterococcus spp. varied, with the highest rates against rifampicin (27%), tetracycline (20%), and erythromycin (18%). Linezolid (5%), vancomycin, ciprofloxacin, and teicoplanin (3% each) had lower prevalence. E. faecium and E. faecalis showed high AMR to rifampicin, erythromycin, and tetracycline. Thirty-two strains (18.98%) grew on VRE Chromoselect agar, while 4 (2 E. faecalis and 2 E. faecium) showed vancomycin resistance by MIC values. E. faecalis carried gelE (45.5%) and asa1 (36%), and E. gallinarum had 9.1% with the asa1 gene. Detecting resistant Enterococcus in bovine milk supports control strategies for enterococci on dairy farms, highlighting AMR concerns in the food chain.

Occurrence of bone sialoprotein-binding protein gene among clinical vancomycin-resistant Enterococcus faecium isolated from bone infections

Vancomycin resistant Enterococcus faecium can be found in the bone resulting human osteomyelitis infections, this could be controlled by some encoding genes that can express the bacterial adhesions, which aid in bacterial colonization for the host bone tissues. Hence, this research aimed to detect the occurrence of bbp gene in clinical vancomycin resistant E. faecium isolated from bone infections. After collection, the samples were isolated and identified using different manual and automated protocols. Furthermore, vanA and bbp genes were molecularly investigated. Results show that 60% of the identified E. faecium were vancomycin-resistant with distribution of 32% and 28% in postsurgery and hematogenous infections, respectively. The prevalence of vanA and bbp genes was 100% in 20 vavancomycin-resistant faecium isolates. These findings show that vanA and bbp expression may be associated with bone infections. We draw the conclusion from this study that vanA and bbp detection can be used as a marker for vavancomycin-resistant faecium in the bone invasion.

Novel combination of nanoparticles and metallo-β-lactamase inhibitor/antimicrobial-based formulation to combat antibiotic resistant Enterococcus sp. and Pseudomonas sp. strains

Nanotechnology presents an innovative strategy to combat the spread of antibiotic resistant bacteria and their resistance genes throughout different ecosystems. To address this challenge, nanoparticles (silver, gold, zinc and copper) alone or in combination with metallo-β-lactamase inhibitor/antimicrobial-based formulation (EDTA/HLE) showed antimicrobial activity against antibiotic resistant Enterococcus sp. and Pseudomonas sp. strains. Furthermore, the observed synergistic effect was detected notably for silver, zinc or copper nanoparticles with EDTA (ethylenediaminetetraacetic acid) and silver nanoparticles with HLE against planktonic Enterococcus sp. strains, or gold nanoparticles+EDTA or HLE against Pseudomonas sp. Regarding activity against bacterial biofilms, zinc nanoparticles combined with either of the reagents caused strong inhibition of developing biofilms of antibiotic resistant Enterococcus sp. Pseudomonas sp. strains, while preformed biofilms were mainly inhibited by silver nanoparticles+reagent. Microscopic analyses confirmed that the antimicrobial activity of nanoparticles was caused by adsorption to the bacterial cell surface, and further enhanced by chelating agents. Hence, we can conclude that nanoparticles+EDTA or HLE could represent a good alternative to limit the spread of antibiotic resistant bacteria in the food chain and the environment.