Vancomycin Resistance Research Articles

Methicillin- and Vancomycin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci Isolated from Hospital Foods: Prevalence and Antimicrobial Resistance Patterns.

This study aimed to investigate the prevalence of Methicillin- and Vancomycin-Resistant Staphylococcus aureus (MRSA, VRSA) and Vancomycin-Resistant Enterococcus (VRE) of hospital food samples in Mashhad, Iran. A total of 357 hospital food samples were collected from 13 hospitals. Enterococcus spp. and Staphylococcus aureus were identified using conventional cultural techniques following genotypic confirmation by PCR. The antibiotic resistance patterns of MRSA, VRSA, and VRE strains were analyzed using the disk diffusion methods. The prevalence of S. aureus and MRSA were 24.37% (87/357) and 22.98% (20.87), respectively. In addition, the vanB gene involved in vancomycin resistance was detected in 1.14% of the S. aureus strains. Enterococci and VRE had a prevalence of 15.4% (55/357) and 21.81% (12/55), respectively. Meat, chicken barbecues, and salad were the most commonly contaminated samples with S. aureus, MRSA, Enterococci, and VRE. PCR detected two vancomycin resistance genes, including vanA (1.81%, 1.55) and vanC2 (20%, 11.55) genes. MRSA strains revealed the highest resistance against penicillin, erythromycin, clindamycin, azithromycin, tetracycline, and gentamicin. The VRSA isolates were resistant to penicillin, ampicillin, oxacillin, cefoxitin, clindamycin, erythromycin, gentamicin, and trimethoprim-sulfamethoxazole. Furthermore, VRE isolates exhibited the highest resistance against quinupristin-dalfopristin, erythromycin, and tetracycline. The results of this study indicated that hospital foods might act as a reservoir of Enterococci spp. and S. aureus strains, which can transfer antibiotic resistance. Moreover, multidrug resistance (MDR) in some MRSA, VRSA, and VRE isolates represents a serious threat to susceptible persons in hospitals.

Rapid Detection of vanA Resistance Gene from E. faecalis Clinical Isolates Using Duplex Loop-Mediated Isothermal Amplification and Triplex PCR Assay.

Today, the spread of vancomycin-resistant strains isolated from Enterococcus faecalis (E. faecalis) has become a major health concern worldwide. Therefore, it is essential to provide a rapid and sensitive assay for identifying vanA gene for timely and appropriate antimicrobial control of resistant enterococcal infections. For this purpose, a cross-sectional study was performed on different clinical specimens of enterococci from Imam Reza hospital, Kermanshah, Iran. The antimicrobial susceptibility testing was determined by disk diffusion and MIC methods. Triplex-PCR and duplex-LAMP assays were also used to identify vanA E. faecalis resistance gene isolates. The results of this study shown that out of 108 Enterococcus isolates, 86, 18, 2, 1, and one isolates of E. faecalis, E. faecium, E. avium, E. psudoavium, and E. raffinosus were identified, respectively. On the other hand, E. faecalis was confirmed in 87 and 88 isolates using duplex-LAMP and triplex PCR, respectively. The LAMP primer set designed in this study can reliably identify seven distinct regions of the vanA gene, and finally the sensitivity, specificity, and the positive and negative predictive values of LAMP assay were shown to be 94.19%, 72.73%, 76.19%, and 93.10%, respectively. In general, sample processing, isothermal reaction and result reporting were completed using the LAMP assay in 75 minutes. Our findings suggest that LAMP assay has been approved as an alternative to the vancomycin resistance Enterococcus genotype (vanA and vanB) compared to other methods and has the advantage of being rapid, time-consuming, and easy for diagnosis.

Nasal colonization of methicillin-resistant Staphylococcus aureus in HIV-infected patients at the Cape Coast Teaching Hospital, Ghana

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be associated with outbreaks in communities (CA-MRSA) and hospitals (HA-MRSA). MRSA isolates are known to be resistant to all beta-lactam antibiotics including methicillin. Moreover, HIV-infected individuals are highly at risk of CA-MRSA due to their weaker immune system. It is therefore important to keep surveillance of the prevalence. Our study aims at determining the prevalence of Staphylococcus aureus and MRSA among HIV-infected participants, the bacteria’s associations, and their antibiotic susceptibility patterns. A cross-sectional study was conducted and nasal swabs from 657 participants attending the HIV clinic at the Cape Coast Teaching Hospital were taken following guidelines. Confirmed S. aureus isolates were taken through antibiotic susceptibility tests per the Kirby–Bauer method, and isolates that were resistant to cefoxitin were considered to be MRSA. The carriage prevalence of S. aureus and MRSA was 44.7% and 8.2%, respectively, among the HIV-infected individuals. There was a significant association between hospitalization and MRSA colonization (p = 0.002), but not S. aureus colonization (p = 0.266). Significant association was also observed between age (p = 0.001), sex (p = 0.0001), and S. aureus colonization. Similarly, differences in age groups (p = 0.001), sex (p = 0.02), and MRSA colonization were statistically significant (p = 0.001). High percentage resistance was exhibited by the isolates to most of the antibiotics. However, this study did not record vancomycin resistance among the MRSA strains. The study showed high colonization of S. aureus and MRSA in HIV-infected patients, which was mostly associated with the age and sex of the individuals.

Clostridioides difficile Infection in Children-An Update.

Clostridioides difficile Infection in Children-An Update.

The VraSR two-component signal transduction system contributes to the damage of blood-brain barrier during Streptococcus suis meningitis

Streptococcus suis (S. suis) is an important zoonotic pathogen that can cause high morbidity and mortality in both humans and swine. As the most important life-threatening infection of the central nervous system (CNS), meningitis is an important syndrome of S. suis infection. The vancomycin resistance associated sensor/regulator (VraSR) is a critical two-component signal transduction system that affects the ability of S. suis to resist the host innate immune system and promotes its ability to adhere to brain microvascular endothelial cells (BMECs). Prior work also found mice infected with ΔvraSR had no obvious neurological symptoms, unlike mice infected with wild-type SC19. Whether and how VraSR participates in the development of S. suis meningitis remains unknown. Here, we found ΔvraSR-infected mice did not show obvious meningitis, compared with wild-type SC19-infected mice. Moreover, the proinflammatory cytokines and chemokines in serum and brains of ΔvraSR-infected mice, including IL-6, TNF-α, MCP-1 and IFN-γ, were significantly lower than wild-type infected group. Besides, blood-brain barrier (BBB) permeability also confirmed that the mutant had lower ability to disrupt BBB. Furthermore, in vivo and in vitro experiments showed that SC19 could increase BBB permeability by downregulating tight junction (TJ) proteins such as ZO-1, β-Catenin, Occludin, and Clauidn-5, compared with mutant ΔvraSR. These findings provide new insight into the influence of S. suis VraSR on BBB disruption during the pathogenic process of streptococcal meningitis, thereby offering potential targets for future preventative and therapeutic strategies against this disease.

Antibiotic Resistance Genes Occurrence in Conventional and Antibiotic-Free Poultry Farming, Italy.

Simple SummaryAntibiotic resistance represents an emergent threat for animals, humans, and the environment. Food-producing animals are directly involved in the dissemination and maintenance of resistant bacteria and their genetic determinants. The genes responsible for resistance mechanisms in bacteria can be located at the chromosomal level or in extra-chromosomal mobile genes, and are transferrable to other bacteria by different modalities. The use of antibiotics in livestock can exercise a selective pressure on resistance determinants and their persistence in intestinal microbiota. In this respect, poultry farming represents a potential driver of resistance genes as these genes can reach the environment or the food chain from poultry litter. In this study, litter samples from conventional flocks (where antibiotics are allowed only for therapeutic purposes) and antibiotic-free farms (where these molecules are excluded) are screened for some resistance genes against antibiotics routinely used in veterinary practice (tetracyclines, aminoglycosides, lincomycin), along with some critically/highly important antibiotics exclusively intended for humans (chloramphenicol, colistin, vancomycin, carbapenems). The results showed the presence of several resistance genes in poultry litter from both farming systems. Interestingly, the highest positivity was observed for tetracycline genes in antibiotic-free flocks, raising some concerns about the role of alternative farming systems in the reduction in antibiotic resistance in food-producing animals.Antimicrobial resistance is a complex and widespread problem threatening human and animal health. In poultry farms, a wide distribution of resistant bacteria and their relative genes is described worldwide, including in Italy. In this paper, a comparison of resistance gene distribution in litter samples, recovered from four conventional and four antibiotic-free broiler flocks, was performed to highlight any influence of farming systems on the spreading and maintenance of resistance determinants. Conventional PCR tests, targeting the resistance genes related to the most used antibiotics in poultry farming, along with some critically important antibiotics for human medicine, were applied. In conventional farms, n. 10 out of n. 30 investigated genes were present in at least one sample, the most abundant fragments being the tet genes specific for tetracyclines, followed by those for aminoglycosides and chloramphenicol. All conventional samples resulted negative for colistin, carbapenems, and vancomycin resistance genes. A similar trend was observed for antibiotic-free herds, with n. 13 out of n. 30 amplified genes, while a positivity for the mcr-1 gene, specific for colistin, was observed in one antibiotic-free flock. The statistical analysis revealed a significant difference for the tetM gene, which was found more frequently in the antibiotic-free category. The analysis carried out in this study allowed us to obtain new data about the distribution of resistance patterns in the poultry industry in relation to farming types. The PCR test is a quick and non-expensive laboratory tool for the environmental monitoring of resistance determinants identifying potential indicators of AMR dissemination.

VanA-Enterococcus faecalis in Poland: hospital population clonal structure and vanA mobilome

The aim of our study was to characterize the epidemiological situation concerning nosocomial vancomycin-resistant Enterococcus faecalis of VanA-phenotype (VREfs-VanA) in Poland by investigating their clonal relationships and the vanA-associated mobilome. One-hundred twenty-five clinical isolates of VREfs-VanA collected between 2004 and 2016 were studied by phenotypic assays, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), PCR detection of plasmid-specific genes, and Tn1546 structure and localization mapping. Selected isolates were subjected to PFGE-S1, Southern hybridization, genomic sequencing and conjugation experiments. The majority of isolates (97.6%) belonged to clonal complexes CC2 and CC87 of E. faecalis. All isolates were resistant to vancomycin and teicoplanin, and resistance to ciprofloxacin and aminoglycosides (high level) was very prevalent in this group. VanA phenotype was associated with 16 types of Tn1546, carrying insertion sequences IS1216, ISEfa4, IS1251 and IS1542, located on repUS1pVEF1, rep1pIP501, rep2pRE25, rep9pAD1/pTEF2/pCF10 and rep6pS86 replicons. The most common Tn1546 B- and BB-type transposons, harbouring one or two copies of IS1216, were inserted between rep18ap200B and repUS1pVEF1 genes and located on ~ 20 kb and 150–200 kb plasmids. VREfs-VanA in Poland represent a polyclonal group, indicating a number of acquisitions of the vanA determinant. The repUS1pVEF1-vanA plasmids, unique for Poland, were the main factor beyond the acquisition of vancomycin resistance by E. faecalis, circulating in Polish hospitals.

Fecal Carriage of Vancomycin-Resistant Enterococci among Hospitalized Patients in Khartoum Sudan

<p><strong>Background:</strong> Vancomycin-resistant Enterococci have emerged as important nosocomial pathogens worldwide. These organisms are often resistant to multiple antimicrobial agents limiting the number of antimicrobial treatment options.</p> <p><strong>Aim</strong>: This study aimed to isolate and identify the vancomycin-resistant enterococci from fecal specimens of hospitalized patients in Soba hospitals- in Khartoum, Sudan.</p> <p><strong>Methods</strong>: The current is a descriptive cross-sectional laboratory-based study. 100 hospitalized patients were selected randomly. A fecal specimen was collected from each participant and inoculated on Kanamycin esculin azide agar and incubated at 37<sup>O</sup>C overnight. Isolated colonies were identified using conventional microbiological methods. Antimicrobial susceptibility testing was determined by using the Kirby-Bauer disc diffusion method. Vancomycin resistance was detected by using vancomycin screening agar. Collected data were analyzed using Statistical Package for Social Science, version 22, <em>P. value</em> <0.05 was considered statistically significant</p> <p><strong>Results: </strong>Out of 100 fecal specimens, 89 <em>Enterococcus</em> <em>spp</em>. were isolated. 1 out of 89 Enterococci 1.1%) were found vancomycin resistance. Resistant to Ceftriaxone was 100%, Rifampicin was 98.9% and streptomycin was 89.9%.</p> <p><strong>Conclusion:</strong> There was a low prevalence of a vancomycin-resistant and wide range of other antimicrobial agents' resistance with an increase in multi-drug resistant strains of enterococci.</p>

424.3: Trends of Antibiotic Resistance in E. Coli, Klebsiella Spp., Pseudomonas Aeruginosa and Enterococcus Spp. Urinary Tract Infection in Renal Transplant Recipients From Pakistan Over a Decade

Introduction: Antimicrobial resistance is a major public threat worldwide. There has been an emergence of multi-drug resistant (MDR) bacterial infections over the last decade. MDR Klebsiella species have become one of the most common nosocomial pathogens in hospitals. In Pakistan, many studies reported a rising trend of resistance to antimicrobials in clinical isolates of Klebsiella species (spp.), E-coli, Pseudomonas aeruginosa and Enterococcus spp. Solid-organ transplant (SOT) recipients are more prone to infections, particularly with MDR organisms due to immunocompromised status, multiple hospital visits, and increased exposure to antibiotics. There is a paucity of data on antibiotic susceptibility patterns among renal transplant recipients from Pakistan. This study is conducted to find the trends in antimicrobial resistance patterns among common organisms isolated in the urinary tract over a 10-year period in renal transplant recipients. The aim is to guide the physicians regarding decisions over empirical antimicrobial choices. Methods: Sindh Institute of Urology and Transplantation (SIUT) is a 700-bedded tertiary care hospital in Karachi, Pakistan. It has had a comprehensive renal transplantation program with more than 6500 transplantations now. A retrospective computerized data review of urine cultures from renal transplant recipients in 2010 and 2020 was conducted. The trend of E.coli, Klebsiella species (spp.) Pseudomonas aeruginosa and Enterococcus spp. were collected. The resistance pattern of amoxicillin-clavulanic acid, ceftriaxone (ceftazidime for Pseudomonas aeurginosa), piperacillin-tazobactam, ciprofloxacin, amikacin, co-trimoxazole, and imipenem were compared over the 10 years period. Results: A total of 2,088 out of 6,249 (33%) and 2902 out of 8,115 (36%) urine cultures were positive in 2010 and 2020 respectively. The most common organisms isolated and their trend in the last decade is shown in figure 1.Over the decade, E-coli strains become 100% resistant to ciprofloxacin, ceftriaxone resistance has increased to 80%, and imipenem to 11%. In Klebsiella spp. imipenem resistance has increased to 19%. There is no significant change in the resistance pattern among Pseudomonas aeurginosa. Regarding Enterococcus spp. there is a rise in vancomycin resistance over the decade from 13% to 17% (Figure 2).Conclusion: Resistance to broad-spectrum antimicrobials has been increased with a>10% increase in carbapenems resistance over the last 10 years. E-coli has particularly become more resistant over the decade. We are also seeing more vancomycin-resistant enterococcus. The alarming increase in resistance may lead to increased morbidity in renal transplant recipients because we are left with only injectable options. We need a robust stewardship program for judicious use of antimicrobials and better infection control measures to contain increasing resistance.

Microbiological and drug resistance patterns of bronchoalveolar lavage samples taken from hospitalized patients in Iran.

Pulmonary diseases are amongst the most common causes of premature death and distressing disorders worldwide. This study aimed to detect the fastidious and routine infectious agents, and their drug resistance patterns in bronchoalveolar lavage (BAL) samples. A total of 44 BAL samples were collected by bronchoscopy from patients with respiratory disorders hospitalized at 2 teaching hospitals in Ilam, Iran. The samples were cultured on routine bacterial culture media to identify the bacterial agents and calculate the colony count. Antibiotic susceptibility was determined by disk diffusion method according to the CLSI protocol. PCR was used to detect the fastidious bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae using the 16srRNA specific primers and Legionella pneumophila using the mip specific primers. Overall, 100 bacterial isolates were isolated by culture from the 44 BAL samples including: Staphylococcus aureus (24, 31.2%), Streptococcus pyogenes (18, 23.4%), Enterococcus spp. (11, 14.3%), Acinetobacter baumannii (11, 14.3%), Pseudomonas aeruginosa (11, 14.3%), Enterococcus spp. (10, 13%), Micrococcus spp. (5, 6.5%), Staphylococcus epidermidis (5, 6.5%) and Klebsiella pneumoniae (5, 6.5%). PCR detected 4 positive samples (9.1%) for Chlamydia pneumoniae but no positive cases for Mycoplasma pneumoniae and Legionella pneumophila. Acinetobacter baumannii showed the highest resistance rate (81.8%) to aztreonam and ceftazidime. Seventy-five percent of the Staphylococcus aureus isolates were resistant to cefoxitin (MRSA) and 83.3% had the mecA gene. Vancomycin resistance was observed in 27.3% of the Enterococcus species (VRE). Resistance to piperacillin, cefotaxime, ciprofloxacin and imipenem was observed in 54.5%, 45.5%, and 36.4% of the Pseudomonas aeruginosa isolates, respectively. The frequency of organisms isolated from the ICU was higher (46%) than from other wards. The presence of MRSA, cephalosporins-resistant Enterobacteriaceae as well as Pseudomonas aeruginosa and Acinetobacter baumannii resistant against piperacillin, imipenem, cefotaxime, aztreonam and ciprofloxacin amongst different wards, especially the ICU ward of the surveyed hospitals, is a major healthcare concern and it is necessary to wisely scrutinize the preventive strategies for antibiotic resistant infections.

Isolation, Identification, Speciation, and Antibiogram of Enterococcus species by conventional methods and Assessment of the Prevalence of vana genotype among VRE

Enterococci are Gram-positive, ovoid cocci that can be found as diplococci or in short chains. These species are found in the typical microbiota of the intestine, oral cavity, vagina, and other areas. Despite being commensals with moderate virulence, these species have lately emerged as important nosocomial infections with increasing drug resistance particularly to vancomycin. This has resulted in their changing patterns of infection that are resistant to conventional antimicrobial therapy. The main objective of this study was to assess the frequency of the VanA genotype among Vancomycin Resistant Enterococci, as well as the isolation, identification, speciation, and antibiotic sensitivity pattern of Enterococci from various clinical specimens. In this six-month study, 500 different clinical specimens such as urine, blood, and pus were collected aseptically from patients suffering from urinary tract infection (UTI), septicemia, and pyogenic illnesses, and a total of 94 Enterococci strains were identified. These isolates were identified and speciated using traditional tests and biochemical processes. Following culture, the disc diffusion technique was used to determine their antibiotic susceptibility pattern, as suggested for common antibiotics. RCR was also used to evaluate the prevalence of the vanA gene among VRE isolates. 88.29% were E. faecalis, 7.88% were E. faecium, 2.12% were E. durans, 1.06 % was E. casseliflavus, and 1.06 % was E. gallinarum, out of a total of 94 isolates. Urine (70.21 %) yielded the most isolates, followed by blood (17.02 %) and pus (17.02 %). Female patients had a higher isolation rate of 73.40 % (69/94) than male patients, who had a rate of 26.59 % (25/94), and the majority of the Enterococcal isolates were from inpatients (62.77 %) rather than outpatients (37.23 %). 30 % of the isolates were hemolytic, whereas 70% were non-hemolytic. The isolates sensitivity patterns revealed that they were resistant to antibiotics such as ampicillin, ciprofloxacin, and gentamicin. The susceptibility test also included 30g discs of vancomycin. Vancomycin resistance is greatest in E. faecium (28 %) 6/83, followed by E. faecalis (8 %) 2\7. All other isolates were vancomycin-susceptible. Vancomycin-resistant isolates made up 8.51 % of the total. Barely urine isolates were tested for nitrofurantoin resistance, which was found to be only 5%. Linezolid sensitivity was found in all of the Enterococci. According to the PCR test for the vanA gene, among total VRE isolates 5 E. faecalis and 1 E. faecium isolates had vanA genotypes with bands of 473bp. A number of studies have revealed an increment in the infection rate and antimicrobial resistance of Enterococci. Elevated isolation rate of VRE has posed threat to therapeutic strategies as now only few antibiotics are susceptible to such isolates. It is thus imperative to execute measures that could stable the VRE augmentation lest a normal commensal would get the status of SARS-CoV-2

The Effect of Antibiotic Resistance and Inappropriate Empirical Antibiotic Therapy on 3-Day and 28-Day Mortality in Bacteremic Patients in the Intensive Care Unit: 5-Year Retrospective Analysis

Aim: The aim of this study was to examine the effects of antibiotic resistance, empirical antibiotic therapy, and comorbid diseases on 3-day and 28-day mortality in patients with bloodstream infections. Material and Methods: Files of the patients with positive blood cultures results, between January 1st, 2015, and January 1st, 2020 were analyzed retrospectively. The primary outcome was 3-day mortality and the secondary outcome was 28-day mortality. Results: A total of 515 patients, 208 (40.4%) female and 307 (59.6%) male, were included in the study. The median age of the patients was 73 (range, 18-95) years. Vancomycin resistance was detected in 8 (3.4%) of 233 gram-positive bacteria. Third-generation cephalosporin, meropenem, and colistin resistance rates of the 282 gram-negative bacteria were found to be 72.7% (n=205), 53.2% (n=150), and 9.9% (n=28), respectively. The 3-day and 28-day mortality rates were 14.4% (n=74) and 64.3% (n=331), respectively. Charlson comorbidity index score (CCIS) (p=0.001) and acute physiology and chronic health evaluation (APACHE) II score (p=0.019) were found to be risk factors for 3-day mortality. Risk factors for 28-day mortality were; age (p<0.001), CCIS (p<0.001), APACHE II score (p=0.001), chronic obstructive pulmonary disease (p=0.007), hospital-acquired infection (p=0.033), and inappropriate antibiotic therapy (p<0.001). Conclusion: There was no association between antibiotic resistance and mortality, but inappropriate antibiotic treatment was found to increase the risk of 28-day mortality. In addition, since high CCIS and APACHE II scores increase the risk of both 3-day and 28-day mortality, we think that considering these scoring systems will reduce the risk of mortality.

Investigation of Vancomycin Resistance and Some Virulence Factors in Enterococci Strains Isolated from Dogs

Investigation of Vancomycin Resistance and Some Virulence Factors in Enterococci Strains Isolated from Dogs

Prevalence of antibiotic resistance genes in drinking and environmental water sources of the Kathmandu Valley, Nepal.

Antibiotic-resistant bacteria-associated infections are responsible for more than 1.2 million annual deaths worldwide. In low- and middle-income countries (LMICs), the consumption of antibiotics for human and veterinary uses is not regulated effectively. Overused and misused antibiotics can end up in aquatic environments, which may act as a conduit for antibiotic resistance dissemination. However, data on the prevalence of antibiotic resistance determinants in aquatic environments are still limited for LMICs. In this study, we evaluated the prevalence and concentration of antibiotic resistance genes (ARGs) in different drinking and environmental water sources collected from the Kathmandu Valley, Nepal, using droplet digital polymerase chain reaction to understand the current situation of ARG contamination. River water and shallow dug well water sources were the most contaminated with ARGs. Almost all samples contained sul1 (94%), and intI1 and tet(A) were detected in 83 and 60% of the samples, respectively. Maximum ARG concentration varied between 4.2 log10 copies/100 ml for mecA and 9.3 log10 copies/100 ml for sul1. Significant positive correlations were found between ARGs (r > 0.5, p < 0.01), except for mecA, qnrS, and vanA. As sul1 and intI1 were detected in almost all samples, the presence of these genes in a given sample may need to be considered as background antibiotic resistance in LMICs. Therefore, monitoring of ARGs, such as β-lactam ARGs, quinolone resistance genes, and vancomycin resistance genes, may provide a better picture of the antibiotic resistance determinants in aquatic environments of LMICs.

Linezolid-resistance Staphylococcus aureus – Prevalence, Emerging Resistance Mechanisms, Challenges and Perspectives

Staphylococcus aureus, an opportunistic pathogen, can root several infections viz skin and tissue infections, bacteraemia, food poisoning, pneumonia, and many other clinical conditions with some variations of virulence factors. In treatment of infections, caused by this Gram-positive pathogen, several antibiotics are being used importantly Methicillin and Vancomycin. This pathogen has high capability of antibiotic resistance development and had evolved new strains such as Methicillin-resistant Staphylococcus aureus (MRSA), and Vancomycin-resistant Staphylococcus aureus (VRSA). Meta-analysis in Ethiopia showed that pooled prevalence of MRSA in environment, food, animal, and human was 54%, 77%, 15%, and 38% respectively (2022). Risk of MRSA isolates from burn ICU was 55 % higher (2018). In Bangladesh, 37.1% isolates from frozen meat chicken (2021) were identified as MRSA. This problem is being dealt with a novel drug called Linezolid which has been proved effective against both MRSA and VRSA. Exacerbating the situation, this pathogen has shown resistance against this unprecedented drug by means of a number of drug resistance mechanisms. Its prevalence has been reporting since the adoption of the drug, but with a minute ratio at one time/place to the very high percentage at another time/place. This inconsistent prevalence must not be ignored, and its surveillance should be augmented as antibiotic treatment is critical for fighting against microbial infections. This review highlights the worldwide reports in which Staphylococcus aureus of either wildtype or Methicillin or Vancomycin resistance that have shown resistance to Linezolid drug for the past 2 decades. At the same time where incidences of Linezolid Resistant Staphylococcus aureus (LRSA) indications are reporting, there is a call for comprehensive strategies to overcome this challenge of antibiotic resistance.

Species prevalence, antimicrobial susceptibility and detection of virulence factors of enterococci isolated from tertiary care hospital

Introduction: Emergence of multidrug resistant nosocomial enterococcus strains emphasizes the need for further investigating enterococci. Objectives: To characterize enterococci from various clinical specimens, to determine the antimicrobial susceptibility pattern and to explore the association between virulence factors and antimicrobial resistance. Material and Methods: Two hundred and eighty three clinical isolates of enterococcus were speciated and subjected to antimicrobial susceptibility testing using Kirby Bauer disc diffusion method. They were screened for vancomycin resistance by vancomycin screening agar method as recommended by Clinical Laboratory Standards Institute 2014, and confirmed by determination of minimum inhibitory concentration using agar dilution and E test. Genotypic confirmation was done by polymerase chain reaction. Virulence factors (haemolysin, gelatinase and biofilm production) were detected phenotypically. Results: Of the 283 enterococci isolated, 12 species were identified; predominant species was Enterococcus faecalis (82.33%). High level gentamicin resistance (HLGR) and vancomycin resistance were observed among 55.57% and 6.01% of Enterococcus isolates respectively. All vancomycin resistant enterococci (VRE) were Enterococcus faecalis and had vanA phenotype and genotype. Sensitivity to linezolid was 100 per cent among enterococci. Hemolysin, gelatinase and biofilm production were seen in 15.90%, 12.36% and 13.43% of enterococcal isolates respectively.

Species prevalence, antimicrobial susceptibility of enterococci isolated from various clinical samples in tertiary care hospital

Introduction: Emergence of multidrug resistant nosocomial enterococcus strains emphasizes the need for further investigating enterococci. Objectives: To characterize enterococci from various clinical specimens, to determine the antimicrobial susceptibility pattern and to explore the association between virulence factors and antimicrobial resistance. Material and Methods: Two hundred and eighty three clinical isolates of enterococcus were speciated and subjected to antimicrobial susceptibility testing using Kirby Bauer disc diffusion method. They were screened for vancomycin resistance by vancomycin screening agar method as recommended by Clinical Laboratory Standards Institute 2020, and confirmed by determination of minimum inhibitory concentration using agar dilution and E test. Genotypic confirmation was done by polymerase chain reaction. Results: Of the 283 enterococci isolated, 12 species were identified; predominant species was Enterococcus faecalis (82.33%). High level gentamicin resistance (HLGR) and vancomycin resistance were observed among 55.57% and 6.01% of Enterococcus isolates respectively. All vancomycin resistant enterococci (VRE) were Enterococcus faecalis and had vanA phenotype and genotype. Sensitivity to linezolid was 100 per cent among enterococci. Conclusion: Our study reveals the occurrence of sizable number of HLGR isolates and emergence of VRE.

Epidemiology, microbiological and clinical characteristics of Enterococcus species bloodstream infections: A 10-year retrospective cohort study from Qatar

Background and objectiveEnterococcus species is one of the leading causes of community and healthcare-associated infections resulting in significant morbidity and mortality. In this study, we aim to evaluate the epidemiology, microbiological and clinical characteristics of Enterococcus Blood Stream Infections (BSIs) over 10 years period in a national secondary care setting. MethodsA retrospective cohort study was conducted on verified cases of enterococcal BSIs in adults from January 2009–December 2018 from specialized care hospitals at Hamad Medical Corporation, Qatar. Epidemiological, microbiological and clinical data were reported and analyzed. ResultsA total of 263 enterococcus BSIs cases were identified, predominant were males (65%) with a median age of 63 (IQR 48–74). E. faecalis and E. faecium were predominate at 93.5% (73.38% and 20.15% respectively). Diabetes was the commonest premorbid condition (54.3%) followed by chronic kidney disease (36.5%). Central lines and genitourinary were the most common sources (18.25%, 14.83% respectively) while no identified source was reported in 45.25% of cases. Ampicillin susceptibility was 82.51% while vancomycin resistance was reported in 10.6% of isolates. Successful bacteremia clearance was achieved in 81.37% of cases at a mean of 4 days (Range 2–5 days) while metastatic complications occurred in 5.3% of cases. Univariate mortality risk analysis was associated with ICU admission, low level of consciousness, high bacteremia scores, and presence of catheters. The 30 days mortality was high at 66.54% with CKD and cancer patients at the highest mortality risks (OR 16.334 (CI 4.2–62.4) and 16 (CI 3–84) respectively. ConclusionSignificant mortality was associated with enterococcus BSI despite low rates for ampicillin and vancomycin resistance necessitating early identification of susceptible patients to instigate suitable preventive measures.

Nigella sativa oil extract: A natural novel specific conjugal transfer inhibitor of vancomycin resistance from vanA/B-resistant Enterococcus faecium to Staphylococcus aureus.

The emergence of vancomycin-resistant Staphylococcus aureus (VRSA) has been identified as one of the most challenging problems in healthcare settings worldwide. Specific conjugation inhibitors' development is critical in the fight against the spread of emerging VRSA. The impact of Nigella sativa oil on VR genes conjugal transfer from Enterococcus faecium (VREtfm) to vancomycin-sensitive S. aureus (VSSA) was investigated in this study. Enterococciwere isolated from retail broilers, fish, cows' milk, and human urine. VR E. faecalis and VREtfm VanA phenotypes were prevalent in retail broiler samples. The VREtfm isolates were dominant, exhibiting high levels of resistance to gentamycin and ciprofloxacin antibiotics, as well as the existence of both vanA and vanB genes and virulence traits (ESP+ , asa1+ ) as determined by PCR. Transconjugant VREtfm strains containing vanA/vabB and 20 kb plasmids (transfer frequency around 103 ) and carrying the Tn1546 transposon were identified. Tn1546 transposon transfer with its VR markers to VSSA was effectively inhibited in treated VREtfm donor strains with a sub-minimum inhibitory concentration of N. sativa oil. This work offers new insights for overcoming VR conjugal transfer utilizing natural N. sativa oil, as well as a suggestion for a novel specialized conjugation inhibitor that could effectively facilitate the difficulty of eliminating VR bacteria from healthcare settings.

Genetic Diversity of Vancomycin Resistance Enterococcus Spp. Isolated from Animal, Human and Environmental Origin

Genetic Diversity of Vancomycin Resistance Enterococcus Spp. Isolated from Animal, Human and Environmental Origin