Species, antibiotic susceptibility profiles and van gene frequencies among enterococci isolated from patients at Mulago National Referral Hospital in Kampala, Uganda

Repurposing fusidic acid as an antimicrobial against enterococci with a low probability of resistance development

Drug repurposing constitutes a strategy to combat antimicrobial resistance, by using agents with known safety, pharmacokinetics, and pharmacodynamics. Previous studies have implemented new fusidic acid (FA) front-loading-dose regimens, allowing higher serum levels than those achievable with ordinary doses. As susceptibility breakpoints are affected by serum level, we evaluated the repurposing of FA as an antimicrobial product against enterococci. FA minimum inhibitory concentrations (MICs) against standard enterococci strains; Enterococcus faecalis ATCC 29212 and Enterococcus faecium ATCC 27270 were 2 and 4 µg/mL, respectively. The MIC against 98 enterococcal clinical isolates was ≤ 8 µg/mL; all would be susceptible if categorized according to recalculated breakpoints (≥ 16 µg/mL), based on the serum level achieved using the front-loading regimen. FA administration in vivo, using the BALB/c mouse infection model, significantly reduced bacterial burden by two to three log10 units in the liver and spleen of mice infected with vancomycin-susceptible and -resistant strains. Exposure of the standard enterococcal strains to increasing, but not fixed, FA concentrations resulted in resistant strains (MIC = 128 µg/mL), with thicker cell walls and slower growth rates. Only one mutation (M651I) was detected in the fusA gene of the resistant strain derived from serial passage of E. faecium ATCC 27270, which was retained in the revertant strain after passage in the FA-free medium. In conclusion, FA can be repurposed as an antimicrobial drug against enterococci with a low probability of mutational resistance development, and can be employed for treatment of infections attributable to vancomycin-resistant enterococci.

Antimicrobial Resistance Profile of Enterococcal Isolates From Clinical Specimens at a Tertiary Care Hospital in Western Maharashtra, India

Background Enterococcus, once benign intestinal flora, has transformed into formidable nosocomial pathogens as a result of the accelerated emergence of antibiotic resistance represents a major global health challenge, particularly within hospital settings. Enterococcus has grown more prevalent in nosocomial infections, such as urinary tract infections (UTIs), surgical site infections (SSIs) and bacteremia. The potential emergence of vancomycin-resistant Enterococcus (VRE) strains further complicates treatment choices for multi-drug resistant (MDR) infections. This study evaluated the magnitude of Enterococcus infections and their antibiotic resistance patterns in a tertiary care hospital. Material and methods A laboratory-based cross-sectional study was conducted from January 2023 to December 2023 (one year) at Krishna Hospital & Medical Research Centre, Karad, India. A total of 189 enterococcalisolates were identified from various clinical specimens, including urine, blood, pus, and other samples. These isolates were subjected to identification and antimicrobial susceptibility testing using the automated VITEK 2 (bioMérieux SA, Marcy-l'Étoile, France) system. VanA and VanB phenotypes were detected based on minimum inhibitory concentration (MIC) values using the VITEK 2 Advanced Expert System (AES) system (bioMérieux SA). Statistical analysis was done using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 21.0, Armonk, NY). Results Among 189 culture-positive enterococcal isolates, the majority were obtained from urine 144 (76%), followed by blood 17 (9%), pus 12 (6%), etc. A larger proportion of these isolates were from female patients 97 (51%) aged over 60 years. A substantial proportion of these isolates originated from in-patient departments (IPD) 178 (94.2%) with intensive care units contributing the highest number 114 (60%) and out-patient departments (OPD) 11 (5.8%). The highest prevalence of infection was observed among patients with a hospital stay of 8 to 14 days (32.3%). E. faecium (57.7%) and E. faecalis (39.6%) were the predominant species with E. faecium displaying significant resistance to benzylpenicillin (96%) and nitrofurantoin (94%) whereas E. faecalis showed higher resistance to high-level gentamicin (80%). E. gallinarum (1.6%)showed complete resistance to benzylpenicillin (100%) and moderate resistance to nitrofurantoin (67%), and high-level gentamicin (67%). Conversely, E. durans showed complete resistance (100%) to both nitrofurantoin and benzylpenicillin. Among 31 VRE isolates, 16 (52%) showed the VanA and 15 (48%) showed the VanB phenotype. Conclusion Antimicrobial resistance among E. faecium and E. faecalis, particularly to benzylpenicillin, high-level gentamicin and nitrofurantoin along with the emergence of resistant species like E. durans and E. gallinarum underscores the urgent need for vigilant antimicrobial stewardship and continuous surveillance of the growing threat of MDR enterococci in clinical settings.

Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) as an Indispensable Tool in Diagnostic Bacteriology: A Comparative Analysis With Conventional Technique

INTRODUCTION

Owing to its accurate diagnosis, rapid turnaround time, cost effectivity, and less rates of error, Matrix-assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) has replaced most of the phenotypic methods of identification. Thus, the objective of this study was to compare and evaluate MALDI-TOF MS to conventional biochemical-to identify bacterial microorganisms.

METHODS

Different bacterial species isolated from 2010 to 2018 (pre-MALDI-TOF era), using routine bio-chemicals were compared to bacterial species isolated from 2019 to August 2021 (post MALDI-TOF), using MALDI-TOF, in the microbiology laboratory of a tertiary care hospital in North India. Chi-Square test (χ2) was used for the evaluation of bacterial identification between biochemical tests and MALDI-TOF MS association with a 95% confidence interval, considering wrong identification in genera or at a species level.

RESULTS

Many different and new genera and species of bacteria could be identified using MALDI-TOF, which was not possible using only routine manual bio-chemicals like Kocuria rhizophilus, Rothia mucilaginosa, Enterococcus casseliflavus, Enterococcus gallinarum, Leuconostoc, Leclercia adecarboxylata, Raoultella ornithological, Cryseobacterium indologenes. Conclusion: Each of the newly identified bacteria played an important role in deciding treatment. Wide use of the MALDI-TOF system will not only strengthen diagnostic stewardship but also encourage antimicrobial stewardship programs.

Bacterial Resistance in Hospital-Acquired Infections Acquired in the Intensive Care Unit: A Systematic Review

PURPOSE

In this review we present the status of the prevalence of bacteria resistant to antibiotics and the main antibiotic resistance genes that are reported in infections acquired in intensive care units (ICU) around the world.

METHODS

A systematic review based on the PRISMA guide was carried out, from the Science Direct, Redalyc, Scopus, Hinari, Scielo, Dialnet, PLOS, ProQuest, Taylor, Lilacs and PubMed/Medline databases. Inclusion criteria of this review were original research study published in a scientific journal in a 10-year time span from 1 January 2017 and 30 April 2022.

RESULTS

A total of 1686 studies were identified, but only 114 studies were considered eligible for inclusion. Klebsiella pneumoniae and Escherichia coli resistant to carbapenems and producers of extended-spectrum β-lactamases (ESBL) are the most frequently isolated pathogens in ICUs in Asia, Africa and Latin America. The blaOXA and blaCTX were antibiotic resistance genes (ARG) most commonly reported in different geographic regions (in 30 and 28 studies, respectively). Moreover, multidrug-resistant (MDR) strains were reported in higher frequency in hospital-acquired infections. Reports of MDR strains vary between continents, with the majority of publications being in Asia and between countries, with Egypt and Iran being highlighted. There is a predominance of few bacterial clones with MDR phenotype, for example, clonal complex 5 Methicillin-Resistant Staphylococcus aureus (CC5-MRSA) circulates frequently in hospitals in the United States, clone ST23-K. pneumoniae is reported in India and Iran, and clone ST260 carbapenemase-producing P. aeruginosa in the United States and Estonia.

CONCLUSION

Our systematic review reveals that ESBL- and carbapenemase-producing K. pneumoniae and E. coli are the most problematic bacteria that are reported, mainly in tertiary hospitals in Asia, Africa, and Latin America. We have also found propagation of dominant clones with a high degree of MDR, becoming a problem due to its high capacity to cause morbidity, mortality and additional hospital costs.

Antibiogram Pattern and Virulence Trait Characterization of Enterococcus Species Clinical Isolates in Eastern India: A Recent Analysis

Objective We aimed to evaluate the current antimicrobial susceptibility pattern and characterize putative virulence traits among Enterococcus species isolates from various clinical specimens in view of their increased isolation rates in both community-related and serious nosocomial infections, as well as resistance to many antibiotics.

Methods Study (April 2017–March 2018) included consecutive, nonrepeated, discrete, and clinically significant isolates of enterococci. Susceptibility testing included detection of high-level aminoglycoside-resistant (HLAR) and glycopeptide-resistant enterococci (GRE). All screen-positive GRE isolates were investigated by polymerase chain reaction for species confirmation and presence of vanA/vanB genes. Virulence genes ace, asa1, cyt, efa, esp, gelE, and hyl were investigated by molecular methods. Hemolysin and biofilm production were studied using phenotypic methods.

Results Of 111 isolates, 89 (80.1%), 16 (14.4%), and 6 (5.4%) were from urine, pus, and blood, respectively, consisting predominantly of E. faecalis (67, 60.4%) and E. faecium (32, 28.8%). E. hirae (5, 4.5%) was the predominant non-E. faecalis non-E. faecium isolate. Other species were E. durans (4, 3.6%), E. avium (2, 1.8%), and E. mundtii (1, 0.9%). Seven (6.3%) out of the 111 isolates were GRE, all vanA genotype. HLAR was observed in 70 (63.1%) isolates, significantly higher in E. faecium than E. faecalis (81.2 vs. 58.2%; p < 0.05). All were susceptible to daptomycin. Hemolysin activity and biofilm production were observed in 38 (34.2%) and 36 (32.4%) isolates. Most frequent virulence genes were efa (77, 69.4%), ace (71, 63.9%), asa1 (67, 60.3%), and gelE (66, 59.4%). There was a predominant association of esp and hyl genes with E. faecium and that of the other genes with E. faecalis.

Conclusion The study will contribute to the existing limited data on virulence trait characterization of clinical E. spp. isolates in India. At the same time, it will help to serve as a guide in the choice of empirical therapy in enterococcal infections leading to favorable clinical outcomes by decreasing the clinical failure, microbiological persistence, and associated mortality, and will lead to future studies on controlling the spread of virulent and multiresistant isolates.

Vancomycin resistant Enterococci and its associated factors among HIV infected patients on anti-retroviral therapy in Ethiopia

BACKGROUND

The emergence of vancomycin resistant Enterococci (VRE) has alarmed the global community due to its tendency for colonization of the gastrointestinal tract. Human Immunodeficiency Virus (HIV) patients are colonized by vancomycin resistant Enterococci than other groups. The aim of this study was to determine the incidence of vancomycin resistant Enterococci and its associated factors among HIV infected patients on Anti-Retroviral Therapy (ART).

METHODS

Institution based cross sectional study was conducted among HIV infected patients on ART at from June 1 to August 30, 2020. Socio-demographic and clinical data were collected by pre-tested structured questionnaire. Stool sample was collected and processed by standard microbiological techniques. Kirby Bauer Disc diffusion method was used to perform antimicrobial susceptibility testing. Data were entered by Epi data version 4.6.0.2 and analyzed by SPSS version 25. Bivariable and multivariable logistic regression model was used to analyze the association between dependent and independent variables. P-values in the multivariable analysis, adjusted odds ratio (AOR) and 95% confidence interval (CI) were used to determine the strength of association. P-value ≤0.05 was considered as significant.

RESULTS

Enterococci spp was isolated on 123/200 (61.50%) patients. Among these isolates, the incidence of vancomycin resistant Enterococci was 11.4% [95% CI: (6.0-17.0)]. Antimicrobial susceptibility patterns against Enterococci showed highest rate of resistance to ampicillin (69.9%). Multidrug resistances were observed in 49.59% of Enterococci isolates. Study participants who had prior antibioticexposurer more than two weeks [AOR = 7.35; 95% CI: (1.2144.64)] and hospitalization for the last six months [AOR = 5.68; 95% CI: (1.09 29.74)] were significantly associated with vancomycin resistant Enterococci.

CONCLUSIONS

In our study high incidence of vancomycin resistant Enterococci was found. Previous exposure to antibiotics for more than two weeks and hospitalization for more than six months were significantly associated with vancomycin resistant Enterococci. The isolated Enterococci had variable degrees of resistance to commonly prescribed antibiotics. Therefore, periodic surveillance on antimicrobial resistance pattern, adhering to rational use of antibiotics and implementing infection prevention protocols may reduce colonization by VRE.

High frequency and diversity of Vancomycin-resistant Enterococci (VRE) in Algerian healthcare settings

The spread of vancomycin-resistant Enterococci (VRE) in Algerian hospital settings is poorly reported. Since the first report in 2006, few data have been available on the molecular mechanism of this resistance across the country. In this study, we investigate the frequency and antibiotic resistance mechanisms of Enterococci strains isolated from hospitalised patients in the Tlemcen university hospital. 191 Enterococcus spp. strains were collected from various clinical samples and were identified using MALDI-TOF-MS. The presence of van genes was investigated by standard PCR and sequencing. Results revealed that E. faecium and E. faecalis strains are the main pathogens identified in the study. Antibiotic susceptibility testing revealed that the resistance rate was high for the majority of antibiotic classes, including glycopeptides, and only linezolid was effective on all strains. Molecular analysis revealed that 52.2% of strains from intensive care unit (ICU) were positive for the vanA gene, including 44.44% E. faecium, 5.55% E. faecalis and 2.22% E. avium. 25.5% of these isolates co-harboured both the vanA and vanC genes, including E. gallinarum (n = 16) and E. faecium (n = 6). In surgical wards (SW) 29.70% of strains harboured the van genes, including 4.90% of E. faecalis harbouring the vanB gene, and of the rest of strains, (24.80%) harboured the vanC genes. Indeed, 9.90% E. gallinarum and 4.90% E. faecalis were positive for vanC1 and 9.90% of E. casseliflavus were positive for the vanC2/C3 gene. The glycopeptide resistance rate was higher among strains from the ICU and was mainly composed by E. faecium strains compared with surgical wards where resistant E. faecalis strains were predominant.

Prevalence of vancomycin-resistant enterococcus in Africa in one health approach: a systematic review and meta-analysis

Vancomycin-resistant enterococci are a global challenge currently as reported by the World Health Organization. It is also important to recognize that combating antimicrobial resistance needs to recognize the interconnections between people, animals, plants and their shared environment in creating public health, the so-called One Health approach. Although the presence of VRE has been described in many regions of the world, there is a lack of comprehensive data indicating their prevalence of in Africa. Therefore, this study aimed to aggregate the result of studies describing VRE reported across multiple regions in Africa. A literature search was conducted on PubMed, Google scholar, and Hinari with the term “Vancomycin resistance enterococcus in Africa” on August 1–3, 2019. All available articles were downloaded to “Endnote version 7.1” then to Microsoft Word 2013. Articles determined to meet our criteria for the review was extracted to Microsoft Excel 2013. Those articles that reported the prevalence of vancomycin resistance Enterococcus obtained from all sample types and published from 2010 to 2019 in the English language were included for the review. A meta-analysis was conducted with OpenMetaAnalyst version R.3.1.0 software. The effect size was determined using a binary random effect model and statically significant considered when p < 0.05. Heterogeneity determined with the inconsistency index. A leave one out analysis used to perform the sensitivity analysis. There were 151 articles identified from the database searches; of this, 36 articles included after extensive review with two independent authors. Out of 4073 samples collected, 1488 isolates identified with an overall pooled prevalence of VRE 26.8% (95% CI; 10.7–43.0%) in Africa with a one-health perspective. The analysis showed that considerable heterogeneity among the studies (I² = 99.97%; p < 0.001). Subgroup analysis in-country, African region, laboratory method, year of publication, and sample source showed that a high prevalence was identified from South Africa (74.8%), South African regions (74.8%), PCR (959.2%), 2010–2015 years (30.3%) and environmental (52.2%), respectively. This meta-analysis indicates that there was a high-pooled prevalence of vancomycin-resistant enterococci in African. A lot should be done to prevent and control the transmission of vancomycin resistance enterococci to a human being from the environment in the continent.

Complete Genomic Analysis of VRE From a Cattle Feedlot: Focus on 2 Antibiotic Resistance

Practices in intensive animal farming such as the extensive use of antimicrobials have significant impacts on the genetic make-up of bacterial communities, especially on that of human/animal commensals. In this report, whole genome sequencing of two vancomycin-resistant enterococci (VRE) isolates from a cattle feedlot in the North West Province, South Africa, was used to highlight the threats that extensive antimicrobial usage in intensive animal rearing represents for environmental microbiomes and the food chain. The genomic DNA of the studied strains was extracted using a DNA extraction kit. Whole-genome sequencing was performed through next-generation sequencing. The genomes of Enterococcus durans strain NWUTAL1 and Enterococcus gallinarum strain S52016 consisted of 3,279,618 and 2,374,946 bp, respectively with G + C contents of 40.76 and 43.13%, respectively. Antibiotic resistance genes (ARG), plasmids and virulence factors (involved in biofilm formation, colonization and copper/silver efflux system), were detected in the genomes of both strains. The presence of these genetic determinants in the studied strains is a cause for concern as they may disseminate and find their way into the food chain via horizontal gene transfer amongst bacteria of the different ecological niches. Issues of this nature cannot be undermined and are relevant as far as food safety is concerned.

Species and drug susceptibility profiles of staphylococci isolated from healthy children in Eastern Uganda

Staphylococci are a key component of the human microbiota, and they mainly colonize the skin and anterior nares. However, they can cause infection in hospitalized patients and healthy individuals in the community. Although majority of the Staphylococcus aureus strains are coagulase-positive, some do not produce coagulase, and the isolation of coagulase-positive non-S. aureus isolates in humans is increasingly being reported. Therefore, sound knowledge of the species and characteristics of staphylococci in a given setting is important, especially isolates from children and immunocompromised individuals. The spectrum of Staphylococcus species colonizing children in Uganda is poorly understood; here, we aimed to determine the species and characteristics of staphylococci isolated from children in Eastern Uganda. Seven hundred and sixty four healthy children less than 5 years residing in Iganga and Mayuge districts in Eastern Uganda were enrolled. A total of 513 staphylococci belonging to 13 species were isolated from 485 children (63.5%, 485/764), with S. aureus being the dominant species (37.6%, 193/513) followed by S. epidermidis (25.5%, 131/513), S. haemolyticus (2.3%, 12/513), S. hominis (0.8%, 4/513) and S. haemolyticus/lugdunensis (0.58%, 3/513). Twenty four (4.95%, 24/485) children were co-colonized by two or more Staphylococcus species. With the exception of penicillin, antimicrobial resistance (AMR) rates were low; all isolates were susceptible to vancomycin, teicoplanin, linezolid and daptomycin. The prevalence of methicillin resistance was 23.8% (122/513) and it was highest in S. haemolyticus (66.7%, 8/12) followed by S. aureus (28.5%, 55/193) and S. epidermidis (23.7%, 31/131). The prevalence of multidrug resistance was 20.3% (104/513), and 59% (72/122) of methicillin resistant staphylococci were multidrug resistant. Four methicillin susceptible S. aureus isolates and a methicillin resistant S. scuiri isolate were mupirocin resistant (high-level). The most frequent AMR genes were mecA, vanA, ant(4')-Ia, and aac(6')-Ie- aph(2'')-Ia, pointing to presence of AMR drivers in the community.