Molecular epidemiology of vancomycin-resistant Enterococcus faecium clinical isolates in a tertiary care hospital in southern Thailand: a retrospective study

Evolution of Peritoneal Dialysis-Associated Peritonitis: Pathogen, Antibiotic Resistance, and the Impact of Lymphocyte Count on Treatment Outcomes

Purpose

Antibiotic administration leads to alterations in pathogenic organisms and antibiotic resistance, posing a significant risk to peritoneal dialysis patients' health. This study aimed to investigate changes in the cause-specific peritonitis, pathogen profiles, antibiotic resistance, and the prognostic factors among patients with peritoneal dialysis-associated peritonitis (PDAP) at our center.

Patients and Methods

We included 463 PDAP patients who attended Peking University Shenzhen Hospital between 2002 and 2023. We analyzed the effects of empirical treatment regimens with cefazolin and ceftazidime or gentamicin.

Results

From 2002 to 2023, we observed that gram-positive staphylococci emerged as the primary causative agents, while the proportion of gram-negative bacillary, enteric peritonitis, and catheter-associated peritonitis decreased significantly. However, the overall cure rate for PDAP and gram-negative bacillary peritonitis declined significantly from 2014 to 2023. Notably, we observed no increase in antibiotic resistance associated with antibiotic drugs use. In addition, reduced lymphocyte counts due to the prevalence of 2019 coronavirus disease (COVID-19) emerged as an independent risk factor for treatment failure in cases of gram-negative bacillary peritonitis.

Conclusion

We did not observe elevated antibiotic resistance in our center when employing empirical dosing strategies involving cefazolin, ceftazidime, or gentamicin. Additionally, we found that a decrease in lymphocyte count due to the COVID-19 epidemic was a significant risk factor for treatment failure in cases of gram-negative bacillary peritonitis at our center. This study provides a foundation for developing clinical treatment strategies for PDAP.

Antimicrobial susceptibility and clinical characteristics of multidrug-resistant polymicrobial infections in Pakistan, a retrospective study 2019-2021

Background: We determined the prevalence of antimicrobial resistance (AMR) in polymicrobial pathogens in Pakistan. Methods: A total of 70,518 clinical samples were collected aseptically and confirmation of isolates and antibiogram were performed by the VITEK 2 system. Results: Of 70,518 samples, 441 (0.62%) were polymicrobial samples, with 882 (1.2%) polymicrobial pathogens with 689 (78.1%) Gram-negative rods (GNRs), 166 (18.8%) Gram-positive cocci and 27 (3.1%) Candida albicans. Among GNRs, 28.8% were Escherichia coli and 25.9% were Klebsiella pneumoniae. Majority, 15.1% of Pseudomonas aeruginosa and K. pneumoniae were found in combination. 30.1% of isolates were ESBL producers, 9.7% carbapenem-resistant organisms, 35.5% MRSA and 6.0% VRE. 100% of E. coli were resistant to ampicillin and 98% of K. pneumoniae were resistant to piperacillin. Conclusion: A high prevalence of AMR in polymicrobial pathogens was observed.

Sociodemographic distributions and molecular characterization of colonized Enterococcus faecium isolates from locality hospitals in Khartoum, Sudan

Background

Enterococcus faecium is an opportunistic pathogen of humans with diverse hosts, encompassing animals as well as human beings. In the past twenty years, there has been a rise in the instances of nosocomial infections that are linked to antibiotic-resistant Enterococcus faecium. The acquisition of diverse antimicrobial resistance factors has driven the global development of robust and convergent adaptive mechanisms within the healthcare environment. The presence of microorganisms in hospitalized and non-hospitalized patient populations has been significantly aided by the facilitation of various perturbations within their respective microbiomes.

Objective

This study aimed to determine the antimicrobial profile, demographic and clinical characteristics, along with the detection of virulence encoding genes, and to find out the clonal genetic relationship among colonized E. faecium strains.

Methodology

A hospital-based cross-sectional study was carried out between October 2018 and March 2020 at four Khartoum locality hospitals in Sudan. The study comprised a total of 108 strains of E. faecium isolated from patients admitted to four locality hospitals in Khartoum. A self-structured questionnaire was used to gather information on sociodemographic traits. Data were analyzed using chi-square test. In all cases, P value ≤ 0.05 with a corresponding 95% confidence interval was considered statistically significant. Moreover, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) was utilized to assess the prevalence of clonal relationships, and the gel was analyzed using CLIQS software.

Results

In this study, the isolation rate of colonized E. faecium strains was 108/170 (63.5%). The colonization of E. faecium and its association with various sociodemographic and clinical features was examined. 73 (67.6%) of patients had multidrug-resistant (MDR), and 22 (20.4%) had extensively drug-resistant (XDR), 73 (67.6%) of patients engaged in self-medication practices. Eighty patients (74.1%) were non-adherence to prescribed antibiotics, while 70 (64.8%) patients reported recent antibiotic usage within the 3 months. The present study suggests that demographic factors may not be significantly associated with the incidence of E. faecium infection except for patients who had a prior history of antibiotic use (P ≤ 0.005). The analysis of virulence genes showed a high prevalence of asa1 gene (22.2%) among strains. In ERIC-PCR the genetic relatedness of E. faecium showed seven identical clusters (A-G) with 100% genetic similarity. This implies clonal propagation in hospitals and communities.

Conclusion

This study found that the incidence of E. faecium isolated from locality hospitals in Khartoum was likely due to the spread of E. faecium clones, thereby highlighting the need for intensifying infection control measures to prevent the spreading of nosocomial infection.

Antimicrobial-Resistant Enterococcus spp. in Wild Avifauna from Central Italy

Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial-resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high-level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug-resistant, with 19.41% extensively drug-resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)-Ia and aac(6′)-Ie-aph(2″)-Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial-resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, too.