Faecium Isolates Research Articles

Systematic screening of 42 vancomycin-resistant Enterococcus faecium strains for resistance, biofilm, and desiccation in simulated microgravity.

Vancomycin-resistant Enterococcus faecium (VRE) presents significant challenges in healthcare, particularly for hospitalized and immunocompromised patients, including astronauts with dysregulated immune function. We investigated 42 clinical E. faecium isolates in simulated microgravity (sim. µg) using a 2-D Clinostat, with standard gravity conditions (1 g) as a control. Isolates were tested against 22 antibiotics and characterized for biofilm formation and desiccation tolerance. Results showed varied responses in minimum inhibitory concentration (MIC) values for seven antibiotics after sim. µg exposure. Additionally, 55% of isolates showed a trend of increased biofilm production, and 59% improved desiccation tolerance. This investigation provides initial insights into E. faecium's changes in response to simulated spaceflight, revealing shifts in antibiotic resistance, biofilm formation, and desiccation tolerance. The observed adaptability emphasizes the need to further understand VRE's resilience to microgravity, which is crucial for preventing infections and ensuring crew health on future long-duration space missions.

Investigation of Antibiotic Resistance of E. coli Associated with Farm Animal Feces with Participation of Citizen Scientists

This paper presents the findings of a large-scale study on antibiotic resistance in bacteria found in farm animal feces across Russia. The study included 6578 samples of farm animal manure from 13 regions in Russia, with the help of citizen scientists. Molecular and microbiological methods were used to analyze 1111 samples of E. coli. The microbiological analysis focused on culturing the microorganisms present in the fecal samples on selective media for E. coli and evaluating the sensitivity of the bacteria to different antibiotics, including ampicillin, tetracycline, chloramphenicol, cefotaxime, and ciprofloxacin. The molecular analysis involved isolating the genomic DNA of the bacteria and conducting PCR assays to detect the vanA, vanB, and mcr-1 antibiotic resistance genes. The results demonstrated significant differences in antibiotic sensitivity of the samples that are morphologically identical to E. coli from different regions. For example, 98.0% and 82.5% of E. coli and other fecal bacterial isolates from the Omsk and Vologda regions lacked antibiotic resistance genes, while 97.7% of samples from the Voronezh region possessed three resistance genes simultaneously. The phenotypic antibiotic sensitivity test also revealed regional differences. For instance, 98.1% of fecal bacterial samples from cattle in the Udmurt Republic were sensitive to all five antibiotics tested, whereas 92.8% of samples from the Voronezh region showed resistance to all five antibiotics. The high level of antibiotic resistance observed may be attributed to their use in farming practices. The distinctive feature of our research is that comprehensive geographical coverage was achieved by using a citizen science platform. Citizen scientists, specifically students from colleges and universities, were responsible for the collection and initial analysis of samples. The project attracted 3096 student participants, enabling the collection and analysis of a significant number of samples from various locations in Russia.

Prevalence and genetic diversity of optrA-positive enterococci isolated from patients in an anorectal surgery ward of a Chinese hospital

Linezolid-resistant enterococci have increased in recent years due to the worldwide spread of acquired resistance genes (cfr, optrA, and poxtA) in clinical, animal, and environmental settings. This study investigated the carriage of optrA-positive enterococci among patients in the anorectal surgery ward in Hangzhou, China, and characterized the genetic context of optrA. A total of 173 wound secretion samples were obtained to screen optrA-positive enterococci. Of the 173 samples, 15 (8.67%) were positive for optrA, including 12 Enterococcus faecalis, two E. faecium, and one E. hirae. Multilocus sequence type analysis revealed that 12 optrA-positive E. faecalis isolates belonged to eight different sequence types (STs), of which ST16 was the main type. Eight optrA variants were identified, whose optrA flanking regions with a fexA gene downstream were bounded by different mobile genetic elements. Furthermore, the optrA gene in 8 out of 15 optrA-positive enterococci could be successfully transferred through conjugation. The findings revealed a high carriage rate of optrA in enterococci from one anorectal surgery ward in China. The dissemination of optrA-positive enterococci isolates in clinical settings should be continually monitored.

Molecular Characterization of Enterococcus faecium Clinical Isolates Harbouring erm (T) from an Italian Hospital.

The presence of erm(T) gene conferring resistance to macrolides, lincosamides and streptogramin B (MLSB), was screened in 296 enterococci collected from clinical samples in a central Italy hospital and seven Enterococcus faecium isolates resulted positive to erm(T) by PCR. All isolates were resistant to erythromycin, tetracycline, ciprofloxacin and ampicillin but susceptible to vancomycin and chloramphenicol. Whole Genome Sequencing analysis revealed that in five E. faecium isolates, all belonging to the sequence type ST80 included in the clonal complex CC17 responsible of nosocomial infections, erm (T) gene was chromosome-located, in different genetic contexts. In E. faecium 735,236, erm (T) was on a 4,159-bp region flanked by two IS1216 and inserted at the 3' end of the mp gene. In E. faecium 711,448 and 739,437, erm (T) was found in a 4,463-bp region identical to that detected in E. faecium 735,236 except for 319bp. In E. faecium 713,729 and 757,415, erm (T) was on a 7,038-bp region flanked by IS1251 and ISEfm2 transposases and encompassed between the genes encoding a recombinase and three hypothetical proteins. erm(T)-carrying minicircles were detected in all isolates by inverse PCR assays demonstrating that erm(T) was included in mobile elements. However, in conjugation assays by filter mating, the erm(T) transferability was unsuccessful. Although macrolides are not used to treat enterococcal infections, the resistance is nonetheless widespread. These antibiotics are critically important in human medicine, but only few studies focused on erm (T)-harbouring clinical enterococci. The emergence of erm (T)-mediated erythromycin resistance among enterococci, potentially transferable to other nosocomial pathogens, should be constantly monitored.

Genomic evaluation of the probiotic and pathogenic features of Enterococcus faecalis from human breast milk and comparison with the isolates from animal milk and clinical specimens.

Enterococcus faecalis is considered a probiotic, commensal lactic acid bacterium in human breast milk (HBM), but there are circulating antibiotic resistant and virulence determinants that could pose a risk in some strains. The study aimed to conduct genomic analysis of E. faecalis isolates recovered from HBM and animal milk and to evaluate their probiotic and pathogenic features through comparative genomics with isolates from clinical specimens (e.g., urine, wound, and blood). Genomic analysis of 61 isolates was performed, including E. faecalis isolates recovered from HBM in Saudi Arabia. Genome sequencing was conducted using the MiSeq system. The fewest antibiotic resistance genes (lsaA, tetM, ermB) were identified in isolates from HBM and animal milk compared to clinical isolates. Several known and unknown mutations in the gyrA and parC genes were observed in clinical isolates. However, 11 virulence genes were commonly found in more than 95% of isolates, and 13 virulence genes were consistently present in the HBM isolates. Phylogenetically, the HBM isolates from China clustered with the probiotic reference strain Symbioflor 1, but all isolates from HBM and animal milk clustered separately from the clinical reference strain V583. Subsystem functions 188 of 263 were common in all analyzed genome assemblies. Regardless of the source of isolation, genes associated with carbohydrate metabolism, fatty acid, and vitamin biosynthesis were commonly found in E. faecalis isolates. In conclusion, comparative genomic analysis can help distinguish the probiotic or pathogenic potential of E. faecalis based on genomic features.

Antimicrobial resistance in Staphylococcus aureus and Enterococci spp. isolates from bloodstream infections in Australian children, 2013 - 2021.

Rising proportions of antimicrobial resistance (AMR) have been observed in both Staphylococcus aureus and Enterococcus spp. isolates. The Australian Group on Antimicrobial Resistance (AGAR) surveillance program captures clinical and microbiological data of isolates detected in blood cultures across Australia. EUCAST 2022 was used for MIC interpretation and the AMR package in R for data analysis. There were 2,091 BSIs with S. aureus and 534 enterococcal BSI episodes over the nine years. Three-quarters of S. aureus BSI episodes were community-onset (78.3%) whilst more than half of enterococcal BSIs were hospital-onset (56.9%). The median age for S. aureus BSIs was 6 years, whilst >50% enterococcal BSIs were in children <12 months old.Fifteen percent of S. aureus isolates were methicillin-resistant (MRSA). Overall, 85.3% of S. aureus were resistant to penicillin, 12.5% resistant to erythromycin, 10.3% to clindamycin, and 4.7% to ciprofloxacin. Resistance to penicillin decreased over time whilst clindamycin resistance increased.Resistance in Enterococcus spp. was almost entirely observed in E. faecium; only one E. faecalis isolate was ampicillin resistant, and no E. faecalis isolates were vancomycin or teicoplanin resistant. Seventy-three percent of E. faecium were resistant to ampicillin, 25.5% to vancomycin (VREfm) and 8.8% to teicoplanin. Significant shifts in the epidemiology and resistance profiles of S. aureus and Enterococcus spp. BSIs in Australian children were observed, making clear the importance of age-stratified reporting in antimicrobial resistance data.

Prevalence of extended-spectrum β-lactamase-producing Enterobacterales and carbapenemase-resistant Enterobacterales in British military cohorts

IntroductionTravel to resource-limited settings is a known risk for acquisition of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) and carbapenem-resistant Enterobacterales (CRE), which are both associated with increased morbidity and mortality. We investigated...

Virulence Potential of ESBL-Producing Escherichia coli Isolated during the Perinatal Period.

The aim of the study was to investigate the virulence factors in Escherichia coli producing extended-spectrum β-lactamase (ESBL) derived from the perinatal fecal colonization flora of mothers and their newborns in a Chinese obstetric ward. Rectal swabs were obtained from mothers prenatally and from their newborns postnatally, and analyzed for ESBL-producing Escherichia coli. The isolates were then whole-genome sequenced. Maternal and neonatal colonization by ESBL-producing E. coli in a Chinese obstetric ward was 18% (31/177) and 5% (9/170), respectively. Fecal ESBL-producing isolates exhibited a significantly lower frequency of virulence factors compared with invasive E. coli. Providing balanced information on screening results is essential, along with conducting a risk assessment for antibiotic treatment strategies. · High ESBL E. coli colonization rates in mothers and neonates perinatally. · Fecal ESBL-producing E. coli showed fewer virulence traits.. · ESBL-producing E. coli knowledge may prompt antibiotic overuse..

Escherichia coli Occurrence and Antimicrobial Resistance in a Swine Slaughtering Process.

The swine production chain can be a reservoir of antimicrobial-resistant Escherichia coli, which transfers resistance genes to other bacteria, serving as an important biomarker in the One Health approach. This study aimed to identify the frequency and antimicrobial resistance profile of E. coli in the swine production chain, assess the presence of extended-spectrum beta-lactamases (ESBL), and compare resistance profiles across different sample types. A total of 622 samples of swine carcasses from various points of the slaughter process (n = 400), swine feces (n = 100), commercial cuts (n = 45), environment (n = 67), and feces from employees (n = 10) of a pig slaughterhouse certified by the Federal Inspection Service, located in São Paulo state, Brazil, were collected. A total of 1260 E. coli isolates were obtained from the samples, with 73.6% of the samples testing positive. The agar disk diffusion test was performed with 10 different classes of antimicrobials. To confirm the production of ESBLs, the isolates were submitted to a double-disk synergism test using cefotaxime, ceftazidime, and amoxicillin with clavulanic acid. Of the total isolates, 80.71% were multidrug resistant. All ESBL-producing isolates were multidrug resistant and resistant to amoxicillin, tetracycline, and chloramphenicol. Isolates from human feces samples had less chance of being multidrug resistant than samples from other sources. The diversity of resistance profiles was verified in the samples, not clustering according to the sources, except for human feces isolates that clustered, evidencing lower antimicrobial resistance variability of these samples. Antimicrobial resistance is significantly present in the pork production chain, necessitating a comprehensive multidisciplinary approach to effectively mitigate risks within the One Health framework.

Emergence of lineage ST150 and linezolid resistance in Enterococcus faecalis: a molecular epidemiology study of UTIs in Tehran, Iran.

Urinary tract infections (UTIs) represent one of the most prevalent bacterial infections, with Enterococcus species now recognized as the second leading cause of these infections. This study focused on symptomatic UTI cases to investigate the risk factors associated with Enterococcus faecalis clinical isolates in patients from Tehran, Iran. Urine samples were collected from patients presenting with symptomatic UTIs. The identification of E. faecalis isolates was performed using standard microbiological techniques, with confirmation via polymerase chain reaction (PCR). Antibiotic susceptibility testing was conducted using the Kirby-Bauer disc diffusion method. The presence of virulence genes was determined through PCR, and biofilm formation was assessed using the microtiter plate method. Additionally, multi-locus sequence typing (MLST) was utilized to genotype linezolid-resistant isolates. Out of 300 UTI cases, E. faecalis was identified as the causative agent in 160 instances. Notably, a high proportion of these isolates exhibited resistance to tetracycline (83.8%) and minocycline (82.5%). Linezolid resistance was observed in 1.3% (n = 2) of the isolates. Conversely, the highest susceptibility rates were observed for vancomycin, penicillin G, ampicillin, and nitrofurantoin, each demonstrating a 98.8% susceptibility rate. Biofilm formation was detected in 25% of the E. faecalis isolates. A significant majority (93.8%) of the isolates harbored the efbA and ace genes, with varying frequencies of esp (72.5%), asa1 (61.2%), cylA (52.5%), and gelE (88.8%) genes. MLST analysis demonstrated that both linezolid-resistant isolates, characterized by strong biofilm formation and the presence of virulence genes, were assigned to the ST150 lineage, which has not been previously documented in clinical settings. The emergence of the ST150 clonal lineage, underscores its clinical significance, particularly in relation to linezolid resistance in E. faecalis. This study adds to the growing body of evidence linking specific clonal lineages with antibiotic resistance, highlighting the critical need for ongoing surveillance and molecular characterization of resistant pathogens.

Sensitivity of dairy calf Salmonella enterica serotype Cerro isolates to infection-relevant stressors.

Salmonella enterica serotype Cerro (S. Cerro) is an emerging Salmonella serotype isolated from cattle, but the association of S. Cerro with disease is not well understood. While comparative genomic analyses of bovine S. Cerro isolates have indicated mutations in elements associated with virulence, the correlation of S. Cerro fecal shedding with clinical disease in cattle varies between epidemiologic studies. The primary objective of this study was to characterize the infection-relevant phenotypes of S. Cerro fecal isolates obtained from neonatal calves born on a dairy farm in Wisconsin, USA. The S. Cerro isolates varied in biofilm production and sensitivity to the bile salt deoxycholate. All S. Cerro isolates were sensitive to sodium hypochlorite, hydrogen peroxide, and acidic shock. However, S. Cerro isolates were resistant to nitric oxide stress. Two S. Cerro isolates were unable to compete with S. Typhimurium during infection of calf ligated intestinal loops, indicating decreased fitness in vivo. Together, our data suggest that S. Cerro is sensitive to some innate antimicrobial defenses present in the gut, many of which are also used to control Salmonella in the environment. The observed phenotypic variation in S. Cerro isolates from a single farm suggest phenotypic plasticity that could impact infectious potential, transmission, and persistence on a farm.IMPORTANCESalmonella enterica is a zoonotic pathogen that threatens both human and animal health. Salmonella enterica serotype Cerro is being isolated from cattle at increasing frequency over the past two decades; however, its association with clinical disease is unclear. The goal of this study was to characterize infection-relevant phenotypes of S. Cerro isolates obtained from dairy calves from a single farm. Our work shows that there can be variation among temporally related S. Cerro isolates and that these isolates are sensitive to killing by toxic compounds of the innate immune system and those used for environmental control of Salmonella. This work contributes to our understanding of the pathogenic potential of the emerging pathogen S. Cerro.

Microbiological Profile and Antimicrobial Susceptibility Pattern of Uropathogens Isolated From Pregnant Women Attending a Tertiary Care Hospital in Central India.

Urinary tract infections (UTIs) are more common in females than males, and during pregnancy, frequency is increased due to hormonal changes affecting the anatomy and physiology. If not treated on time, complications may develop in both the mother and fetus. This study aimed to analyze the microbiological (bacterial and yeast) profile of the isolated uropathogens and their antimicrobial susceptibility. Aseptically collected urine specimens were processed by the standard loop method. Identification of uropathogens was done by standard microbiological tests, and antimicrobial susceptibility was performed as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Out of 400 study participants, UTI was detected in 26.75% (107/400) of cases. Overall, Escherichia coli (42.99%, 46/107) was the most frequently isolated uropathogen followed by Candida species (20.56%, 22/107), whereas, among gram-positive bacteria, Enterococcus faecalis (7.47%, 8/107) was the commonest. Among Enterobacterales, extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) production was observed in 19.35% (12/62, eight E. coli and four Klebsiella) and 6.45% (4/62, all E. coli) isolates, respectively. However, all the gram-negative organisms showed 100% (n=70) sensitivity to carbapenems. Among staphylococci, 50% (2/4) of isolates were methicillin-resistant, and high-level aminoglycoside resistance (HLAR) was observed in 75% (6/8) of Enterococcus faecalis isolates, but all were sensitive to vancomycin, linezolid, and nitrofurantoin. Among Candida species, non-albicans Candida (NAC) species (59%, 13/22) outweigh the number of Candida albicans (41%, 9/22), with Candida tropicalis (22.72%, 5/22) being the commonest NAC. All the Candida species were susceptible to voriconazole, whereas fluconazole resistance was observed in 31.81% (7/22) of Candida isolates, with a higher percentage in NAC species (22.72%, 5/22) than in Candida albicans (9.09%, 2/22). UTIs in pregnancy are caused by a spectrum of both gram-negative bacilli and gram-positive cocci. Moreover, there is a rise of both Candida albicans and NAC species as uropathogens, with the emergence of fluconazole resistance. There is an increased prevalence of asymptomatic bacteriuria in pregnancy, which necessitates the screening of pregnant females for UTI using culture and antimicrobial susceptibility testing.

The cytolytic capacity of Enterococcus faecalis isolates from cheese, yogurt, and curd

The cytolytic capacity of Enterococcus faecalis isolates from cheese, yogurt, and curd

Prevalence and Molecular Epidemiology of Intestinal Colonization by Multidrug-Resistant Bacteria among Hematopoietic Stem-Cell Transplantation Recipients: A Bulgarian Single-Center Study.

Background/Objectives: Intestinal colonization by multidrug-resistant (MDR) bacteria is considered one of the main risk factors for invasive infections in the hematopoietic stem-cell transplant (HSCT) setting, associated with hard-to-eradicate microorganisms. The aim of this study was to assess the rate of intestinal colonization by MDR bacteria and their microbial spectrum in a group of post-HSCT patients to study the genetic determinants of beta-lactam and glycopeptide resistance in the recovered isolates, as well as to determine the epidemiological relation between them. Methods: The intestinal colonization status of 74 patients admitted to the transplantation center of University Hospital "St. Marina"-Varna in the period January 2019 to December 2021 was investigated. Stool samples/rectal swabs were screened for third-generation cephalosporin and/or carbapenem-resistant Gram-negative bacteria, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Stenotrophomonas maltophilia. Identification and antimicrobial susceptibility testing were performed by Phoenix (BD, Sparks, MD, USA) and MALDI Biotyper sirius (Bruker, Bremen, Germany). Molecular genetic methods (PCR, DNA sequencing) were used to study the mechanisms of beta-lactam and glycopeptide resistance in the collected isolates, as well as the epidemiological relationship between them. Results: A total of 28 patients (37.8%) were detected with intestinal colonization by MDR bacteria. Forty-eight non-duplicate MDR bacteria were isolated from their stool samples. Amongst them, the Gram-negative bacteria prevailed (68.8%), dominated by ESBL-producing Escherichia coli (30.3%), and followed by carbapenem-resistant Pseudomonas sp. (24.2%). The Gram-positive bacteria were represented exclusively by Enterococcus faecium (31.2%). The main beta-lactam resistance mechanisms were associated with CTX-M and VIM production. VanA was detected in all vancomycin-resistant enterococci. A clonal relationship was observed among Enterobacter cloacae complex and among E. faecium isolates. Conclusions: To the best of our knowledge, this is the first Bulgarian study that presents detailed information about the prevalence, resistance genetic determinants, and molecular epidemiology of MDR gut-colonizing bacteria in HSCT patients.

Cytotoxic Activity of Vancomycin-Resistant Enterococci Isolated from Hospitalised Patients.

Vancomycin-resistant enterococci (VRE) are considered one of the main nosocomial pathogens due to their increasing antibiotic resistance and ability to cause life-threatening infections in humans. This study included VRE isolates obtained from various specimens including urine, blood, faeces, wounds, sputum, and oral cavity wash. Of the 37 strains, 30 (81.1%) and 7 (18.9%) were identified by MALDI TOF as Enterococcus faecium and Enterococcus faecalis, respectively. The clinical vancomycin-resistant enterococci exhibited multi-drug resistance (MDR). Apart from vancomycin, the enterococci exhibited resistance to penicillins (89.1 to 100%), fluoroquinolones (100%), rifampicin (86.5%), tetracycline (27%), aminoglycosides (56.8 to 86.5%), quinupristin-dalfopristin (35.1%), and chloramphenicol (10.8%). Moreover, resistance to linezolid and tigecycline emerged among the tested vancomycin-resistant enterococci. The analysis of aminoglycoside modifying enzyme (AME) genes showed the presence of bifunctional aac(6')-Ie-aph(2″)-Ia genes contributed to high-level aminoglycoside resistance (HLAR) in the E. faecalis and E. faecium isolates. The other AME gene, i.e., aph(3')-IIIa, was also found in the VRE isolates. All strains carried the vanA gene. Enterococci from colonised gastrointestinal tracts (1/2.7%) and from infection (6/16.2%) showed cytotoxic activity against the human epithelial cell line HEp-2.

The effect of the nisin-based pharmaceutical formulation used in the treatment plan for cows with subclinical mastitis on the milk microbiota

Due to the growing threat of antimicrobial resistance, the search and development of new drugs to treat infectious mammary gland diseases of high yielding cows is an urgent task. The paper presents data on the microbiota composition of milk from high yielding cows suffering from subclinical mastitis; 144 microbial isolates were recovered from 70 milk samples; with the highest number of Staphylococcus aureus and Streptococcus dysgalactiae detected (22.2 and 16.0%, respectively). The study showed that a significant number of Staphylococcus aureus isolates (53.1%) were resistant to I generation cephalosporins; 52.6% of the isolated Streptococcus dysgalactiae strains showed resistance to tetracyclines; 33.3% of Staphylococcus haemolyticus isolates were resistant to macrolides. 42.1; 35.3 and 62.5% of Enterococcus faecium, Aerococcus viridans and coliform bacteria isolates, respectively, were resistant to penicillins. 38.5% of Staphylococcus epidermidis isolates were found to be resistant to tetracyclines. Corynebacterium pseudotuberculosis isolates showed equal resistance to penicillin and tetracycline antimicrobials (20.0%). The research revealed presence of multi-drug resistant coliform bacteria, Streptococcus dysgalactiae, Aerococcus viridans, Staphylococcus aureus strains. Experiments to study the effect of the new nisin-based pharmaceutical formulation on microbiota of milk from cows with subclinical mastitis were carried out using 35 high yielding cows. A microbiological testing of cow milk on day 14 from the beginning of the treatment showed that the number of microbiota-free samples increased to 88.6%, while in 1.4% of cases Staphylococcus aureus isolates were recovered (103 CFU/mL). The titers of coliform and Staphylococcus aureus bacteria isolated in 1.4% (101 CFU/mL) and 2.7% (102 CFU/mL) of cases, respectively, were not etiologically significant.

Expression of Pili Genes (ebpA and ebpC) Associated with Multi Drug Resistant Enterococcus faecalis Isolates

The antibiotic susceptibility was determined for 118 clinical E. faecalis isolates , the isolates showed various levels of susceptibilities to different antibiotics and 70.5% of these isolates were multidrug resistant. The relative expression of ebpA gene in six multidrug resistance E. faecalis isolates was determined in comparison with antibiotic-sensitive isolates selected as a control sample. The isolate 21 from root canal (multi drug resistance) showed increasing in expression in comparison with antibiotic sensitive isolates of E. faecalis. The relative expression of ebpC gene in multidrug resistance E. faecalis isolates was determined in comparison with antibiotic sensitive isolates which were selected as control samples. The isolate 21 from root canal and the isolates 19 from urine (multi drug resistance) showed high expression in comparison with antibiotic sensitive isolates of E. faecalis. The expression of ebpA and ebpC genes in multi drug resistance isolates in relation to their sources showed that urine group gave a high rate of expression of ebpC followed by root canal in comparison with ebpA expression. In contrast, the vagina group gave a higher expression of ebpA than ebpC. The findings of the present investigation revealed a significant correlation (P=0.05) between the multi-drug resistance and gene expression of ebpA gene, while there is no significant (P=0.05) correlation with ebpC.

Faecal microbiota and cytokine profiles of rural Cambodian infants linked to diet and diarrhoeal episodes

The gut microbiota of infants in low- to middle-income countries is underrepresented in microbiome research. This study explored the faecal microbiota composition and faecal cytokine profiles in a cohort of infants in a rural province of Cambodia and investigated the impact of sample storage conditions and infant environment on microbiota composition. Faecal samples collected at three time points from 32 infants were analysed for microbiota composition using 16S rRNA amplicon sequencing and concentrations of faecal cytokines. Faecal bacterial isolates were subjected to whole genome sequencing and genomic analysis. We compared the effects of two sample collection methods due to the challenges of faecal sample collection in a rural location. Storage of faecal samples in a DNA preservation solution preserved Bacteroides abundance. Microbiota analysis of preserved samples showed that Bifidobacterium was the most abundant genus with Bifidobacterium longum the most abundant species, with higher abundance in breast-fed infants. Most infants had detectable pathogenic taxa, with Shigella and Klebsiella more abundant in infants with recent diarrhoeal illness. Neither antibiotics nor infant growth were associated with gut microbiota composition. Genomic analysis of isolates showed gene clusters encoding the ability to digest human milk oligosaccharides in B. longum and B. breve isolates. Antibiotic-resistant genes were present in both potentially pathogenic species and in Bifidobacterium. Faecal concentrations of Interlukin-1alpha and vascular endothelial growth factor were higher in breast-fed infants. This study provides insights into an underrepresented population of rural Cambodian infants, showing pathogen exposure and breastfeeding impact gut microbiota composition and faecal immune profiles.

Genomics of Staphylococcus aureus and Enterococcus faecalis isolated from the ocular surface of dry eye disease sufferers

Ocular surface inflammatory disorders, such as dry eye, are becoming increasingly prevalent. Developing new treatment strategies targeting harmful bacteria could provide significant therapeutic benefits. The purpose of this study was to characterize the common ocular pathogen Staphylococcus aureus and the rarer endophthalmitis-associated species Enterococcus faecalis isolated from the ocular surface of dry eye disease patients in Norway. Together the 7 isolates (5 S. aureus and 2 E. faecalis) comprise the complete set of members of each species isolated in our previous study of the ocular microbiome of 61 dry eye sufferers. We aimed to investigate the pathogenic potential of these isolates in relation to ocular surface health. To this end, we used whole genome sequencing, multiplex PCR directed at virulence genes and antibiotic susceptibility tests encompassing clinically relevant agents. The E. faecalis isolates showed resistance to only gentamicin. S. aureus isolates displayed susceptibility to most of the tested antibiotics, except for two isolates which showed resistance to trimethoprim/sulfamethoxazole and three isolates which were resistant to ampicillin. Susceptibilities included sensitivity to several first-line antibiotics for treatment of ocular infections by these species. Thus, treatment options would be available if required. However, spontaneous resistance development to gentamicin and rifampicin occurred in some S. aureus which could be a cause for concern. Whole genome sequencing of the isolates showed genome sizes ranging from 2.74 to 2.83 Mbp for S. aureus and 2.86 Mbp for E. faecalis, which is typical for these species. Multilocus sequence typing and phylogenetic comparisons with previously published genomes, did not suggest the presence of eye-specific clusters for either species. Genomic analysis indicated a high probability of pathogenicity among all isolates included in the study. Resistome analysis revealed the presence of the beta-lactamase blaZ gene in all S. aureus isolates and the dfrG gene in two of them; while E. faecalis isolates carried the lsa(A) gene which confers intrinsic resistance to lincosamides and streptogramin A in this species. Screening for virulence factors revealed the presence of various pathogenicity associated genes in both S. aureus and E. faecalis isolates. These included genes coding for toxin production and factors associated with evading the host immune system. Some of the identified genes (tst, hylA &hylB) are suggested to be linked to the pathophysiology of dry eye disease. Lastly, the presence of specific S. aureus virulence genes was confirmed through multiplex PCR analysis.

Virulence Factors and Susceptibility to Ciprofloxacin, Vancomycin, Triclosan, and Chlorhexidine among Enterococci from Clinical Specimens, Food, and Wastewater.

Enterococcus faecalis and E. faecium are opportunistic pathogens commonly found in the microbiota of humans and other animals as well as in the environment. This article presents the results of antimicrobial susceptibility testing using phenotypic methods (broth microdilution and standardized disk diffusion) on selected clinical, food, and wastewater isolates of E. faecalis and E. faecium. The isolates were divided into subgroups based on their sensitivity to the following antibiotics: vancomycin (VAN) and ciprofloxacin (CIP), and biocides triclosan (TCL) and chlorhexidine (CHX). The study also investigated in vitro virulence factors, including biofilm formation ability, cell surface hydrophobicity (CSH) and β-hemolysis, to explore aspects of pathogenesis. In our study, regardless of the isolation source, VAN-resistant (VAN-R) and CIP-resistant (CIP-R) E. faecalis and E. faecium were detected. The highest proportion of CIP-R strains was found among clinical isolates of E. faecalis and E. faecium, with clinical E. faecium also showing the highest proportion of VAN-R strains. But the highest proportion of VAN-R E. faecalis strains was found in wastewater samples. The highest TCL MIC90 values for E. faecalis were found in wastewater isolates, while for E. faecium, the highest TCL MIC90 values were observed in food isolates. The highest CHX MIC90 values for both E. faecalis and E. faecium were identified in clinical specimens. The results obtained for E. faecalis did not indicate differences in TCL MIC and CHX MIC values with respect to sensitivity to VAN and CIP. Higher CHX MIC50 and CHX MIC90 values were obtained for CIP-R and VAN-R E. faecium. Among the tested isolates, 97.75% of the E. faecalis isolates produced biofilm, while 72.22% of the E. faecium isolates did so as well. In biofilm-forming strength categories III and IV, statistically significantly higher proportions of CIP-susceptible (CIP-S) and VAN-susceptible (VAN-S) E. faecalis were determined. In category III, there is no statistically significant difference in E. faecium CIP sensitivity. In category IV, we had a significantly higher proportion of CIP-R strains. On the other hand, the association between the moderate or strong category of biofilm formation and E. faecium VAN susceptibility was not significant. E. faecalis isolated from wastewater had a CSH index (HI) ≥ 50%, categorizing them as "moderate", while all the other strains were categorized as "low" based on the CSH index. Among the E. faecalis isolates, cell surface hydrophobicity indices differed significantly across isolation sources. In contrast, E. faecium isolates showed similar hydrophobicity indices across isolation sources, with no significant difference found. Moreover, no correlation was found between the enterococcal cell surface hydrophobicity and biofilm formation in vitro. After anaerobic incubation, β-hemolytic activity was confirmed in 19.10% of the E. faecalis and 3.33% of the E. faecium strains.