Escherichia coli is one of the most important pathogens causing bloodstream infections (BSIs) throughout the world. We sought to characterize the phylogroup classification, major human sequence types ...(STs), antimicrobial resistance, presence of selected antimicrobial resistance and virulence genes, and genetic diversity of E. coli isolated from patients with BSIs at the University Hospital in Iran. A total of 100 E. coli bloodstream isolates were collected between December 2020 and June 2022. This study used PCR to investigate phylogenetic groups (A, B1, B2, C, D, E, and F), four major STs (ST69, ST73, ST95, and ST131), antibiotic resistance genes (ARGs), virulence-associated genes (VAGs), and pathogenicity islands (PAIs). Antimicrobial susceptibility testing was done by disk diffusion method. Genetic diversity was analyzed by repetitive element sequence-based PCR (REP-PCR). The phylogenetic group B2 (32%) predominated, followed by phylogenetic group E (25%). ST131 (28%) was the most prevalent ST and the majority of these isolates (89.3%) were of serotype O25b. Most of E. coli isolates (75%) were categorized as multidrug resistant (MDR) with high rates of resistance (>55%) to ampicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, cefazolin, and ceftriaxone. The most frequent ARGs were bla TEM (66%), sul1 (57%), and sul2 (51%). The most prevalent VAGs and PAIs were fimH (type 1 fimbriae adhesin; 85%), aer ( iucC ) (aerobactin; 79%), traT (serum resistance; 77%), iutA (aerobactin siderophore receptor; 69%), and PAI IV 536 (75%), respectively. The highest rate of ARGs and VAGs was observed in the ST131 isolates. REP-PCR analysis showed high diversity among the studied isolates. The high prevalence of MDR septicemic E. coli with different types of ARGs, VAGs and genotypes is an extremely worrisome sign of BSIs treatment and poses a major threat for hospitalized patients. Active surveillance, stringent prescribing policies, increasing the awareness of ARGs among clinicians and re-defining the infection control measures are essential to curb the dissemination of these strains.
ABSTRACT
The probiotic potential of Lactobacillus species isolated from infant feces was investigated. For this study, the antibiotic susceptibility, tolerance in gut‐related conditions, ...antimicrobial activity, and ability to adhere to a human colorectal adenocarcinoma cell line (Caco‐2 cells) of four common Lactobacillus species (Lactobacillus paracasei n = 15, Lactobacillus rhamnosus n = 45, Lactobacillus gasseri n = 20 and Lactobacillus fermentum n = 18) were assessed. Most isolates that which were sensitive to imipenem, ampicillin, gentamycin, erythromycin and tetracycline were selected for other tests. L. gasseri isolates had the greatest sensitivity to gastric and intestinal fluids (<10% viability). L. fermentum (FH5, FH13 and FH18) had the highest adhesion to Caco‐2 cells. The lowest antibacterial activity against pathogenic bacteria was shown by L. gasseri strains in spot tests. Furthermore, non‐adjusted cell‐free culture supernatants with low pH had greater antimicrobial activity, which was related to organic acid. The results showed that some isolates of L. rhamnosus and L. fermentum are suitable for use as a probiotic.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Hospital infections such as ventilator-associated pneumonia (VAP) due to multidrug-resistant Klebsiella pneumoniae (MDR-KP) strains have increased worldwide. In addition, biofilm production by these ...resistant isolates has confronted clinicians with higher treatment failure and infection recurrence. Given the paucity of new agents and limited data on combination therapy for MDR-KPs, the present study sought to evaluate the in vitro activity of several antibiotic combinations against planktonic and biofilm MDR-KPs isolated from patients with VAP. All 10 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates demonstrated multidrug resistance against the tested antibiotics. At planktonic mode, combinations of colistin-meropenem and amoxicillin/clavulanate in combination with meropenem, colistin, or amikacin showed synergism against 60-70% isolates. On the other hand, in the biofilm state, colistin-based combinations exhibited synergism against 50-70% isolates and the most effective combination was colistin-amikacin with 70% synergy. The results revealed that combinations of amoxicillin/clavulanate with colistin, meropenem, or amikacin in the planktonic mode and colistin with amoxicillin/clavulanate, meropenem, or amikacin in the biofilm mode could effectively inhibit CRKP isolates, and thus could be further explored for the treatment of CRKPs.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Biofilms play a role in recalcitrance and treatability of bacterial infections, but majority of known antibiotic resistance mechanisms are biofilm-independent. Biofilms of Pseudomonas aeruginosa, ...especially in cystic fibrosis patients infected with the alginate producing strains in their lungs, are hard to treat. Changes in growth-related bacterial metabolism in biofilm affect their antibiotic recalcitrance which could be considered for new therapies designed based on these changes. In this study, effects of nitrate, arginine, and ferrous were investigated on antibiotic recalcitrance in alginate-encapsulated P. aeruginosa strains isolated from cystic fibrosis patients in the presence of amikacin, tobramycin, and ciprofloxacin. Also, expression of an efflux pump gene, mexY, was analyzed in selected strains in the presence of amikacin and ferrous.
Clinical P. aeruginosa strains were isolated from cystic fibrosis patients and minimum inhibitory concentration of amikacin, tobramycin, and ciprofloxacin was determined against all the strains. For each antibiotic, a susceptible and a resistant or an intermediate-resistant strain were selected, encapsulated into alginate beads, and subjected to minimal biofilm eradication concentration (MBEC) test. After determining MBECs, sub-MBEC concentrations (antibiotics at concentrations one level below the determined MBEC) for each antibiotic were selected and used to study the effects of nitrate, arginine, and ferrous on antibiotic recalcitrance of encapsulated strains. Effects of ferrous and amikacin on expression of the efflux pump gene, mexY, was studied on amikacin sensitive and intermediate-resistant strains. One-way ANOVA and t test were used as the statistical tests.
According to the results, the supplements had a dose-related effect on decreasing the number of viable cells; maximal effect was noted with ferrous, as ferrous supplementation significantly increased biofilm susceptibility to both ciprofloxacin and amikacin in all strains, and to tobramycin in a resistant strain. Also, treating an amikacin-intermediate strain with amikacin increased the expression of mexY gene, which has a role in P. aeruginosa antibiotic recalcitrance, while treating the same strain with ferrous and amikacin significantly decreased the expression of mexY gene, which was a promising result.
Our results support the possibility of using ferrous and arginine as an adjuvant to enhance the efficacy of conventional antimicrobial therapy of P. aeruginosa infections.
The diagnosis of urinary tract infections (UTIs) is usually based on the results of urine culture, but it is time-consuming, labor-intensive and has a low sensitivity. The aim of this study was to ...develop multiplex high-resolution melting assay (MHRM) for the simultaneous detection of five common bacterial pathogens (
,
,
,
, and group B streptococci (GBS)) directly from urine samples. A total of 287 urine specimens were evaluated by HRM assay and the results were compared with the conventional culture method. Five different melt curves generated and differentiated five bacterial pathogens. The detection limit of the MHRM assay was 1.5 × 10
CFU/ml for
and
and 1.5 × 10
CFU/ml for
,
and GBS. Compared to culture, the specificity of the MHRM assay ranged from 99.3 to 100%, and sensitivity 100% for all test pathogens. The MHRM assay developed in the current study might be functional tool for the diagnosis of UTIs and has the potential for direct detection of the organism in the clinical samples. Additionally, it creates results in less than 5 h, helping clinicians to start treatment with appropriate antimicrobial agents. This method could be a useful supplement to urine culture.
Background/significance Salmonella gastroenteritis causes significant morbidity among pediatric patients, mainly in developing world, such as the Middle East and North Africa (MENA) region. ...Concurrently, data from MENA countries like Iran, regarding prevalence of Salmonella serotypes, antimicrobial susceptibility, and biofilm production is scarce. Material & methods Slide agglutination was used to determine the serogroup of 140 Salmonella isolates recovered from 4477 stool specimens collected from children with gastroenteritis, and isolates were serotyped by PCR assay. The antimicrobial susceptibility of isolates to five first line drugs was assessed by disk diffusion assay using CLSI guidelines. Semi-quantitative evaluation of biofilm production was done by microtiter plate assay followed by PCR detection of biofilm-associated virulence genes csgD, pefA, and bcsA for each isolate. Results Nearly 94% of Salmonella isolates were recovered from less than or equai to 5-year-old patients, and 99% of isolates were non-typhoidal. While we found extensive diversity among Salmonella isolates, serogroup D (46%) predominated, and Salmonella Enteritidis (41%) was the most common serotype that showed the highest antimicrobial susceptibility rate (> 96%). For the first time in Iran, S. Newport serotype from human specimens was isolated. Most isolates were sensitive to all test antimicrobials, but 35% of isolates were not-typed (NT) that showed the highest resistance with 48% being resistant to greater than or equal to 1 test antimicrobial. Majority of isolates made weak (or no) biofilm, and we found a weak association between antimicrobial susceptibility, biofilm production, or virulence genes csgD, pefA, and bcsA. Conclusions The most effective measure that may control pediatric salmonellosis outbreaks is raising awareness of parents of preschoolers about food safety. Isolation of highly diverse Salmonella serotypes, including many commonly isolated from animals, indicates widespread contamination of the food chain. Majority of serotypes were sensitive to first-line antimicrobials, thus presently, pediatric Salmonella infections in this region may be controlled by conventional antimicrobials. However, despite the current trend, an imminent emergence of resistant Salmonella strains is foreseen, since various serotypes resistant to > 1 antimicrobial agent are typically associated with animals. Our results warrant further investigation that includes correlation analysis of clinical data regarding treatment outcomes, and serotype attributes like virulence genes. Keywords: Salmonella serogroups, Serotypes, Antimicrobial susceptibility, Biofilm, Virulence genes
Background and Objective: In light of the pivotal role played by personal protective equipment (PPE) in mitigating the transmission of the novel coronavirus, this study aimed to investigate the ...utilization of personal protective equipment in the context of the COVID-19 pandemic among medical personnel and students affiliated with Lorestan University of Medical Sciences in the year 2019.
Methods: This cross-sectional, descriptive research study collected essential data, encompassing personal characteristics and inquiries concerning the use of personal protective equipment, the extent of their utilization, training regarding proper equipment use, and adherence to health guidelines, including hand hygiene and disinfectant usage. Data were gathered through a questionnaire developed in accordance with international standards, specifically the PPE Safe Survey. The questionnaire was administered to medical staff, including physicians, nurses, and medical students, working in healthcare facilities that admitted COVID-19 patients within the Lorestan University of Medical Sciences, situated in Khorramabad.
Results: Our investigation involved a total of 201 participants, comprising 82 (40.8%) males and 119 (59.2%) females. The average age of the participants was 32 years, with an average daily duration of personal protective equipment utilization amounting to 8.9 hours. Notably, 44 (21.9%) participants worked in emergency wards, 63 (31.3%) in general medical wards, 12 (6.0%) in administrative departments, 14 (7.0%) in surgical units, 11 (5.5%) in anesthesiology, 17 (8.5%) in intensive care units, and 40 (19.9%) in miscellaneous contexts.
Conclusion: The study findings underscore the imperative need for healthcare professionals to consistently employ suitable personal protective equipment, encompassing face masks, eye protection, gowns, and eye shields. Furthermore, our study highlights the significance of appropriate training and rigorous adherence to equipment utilization protocols during healthcare tasks, coupled with consistent hand hygiene practices in healthcare facilities.
One of the most prevalent drug-resistant bacteria is methicillin-resistant
(MRSE) causing healthcare infections. Previously, a meta-analysis study on the frequency of MRSE was conducted from Mar 2006 ...to Jan 2016 in Iran. The present study aimed to evaluate the changes in this prevalence in the last 5 years in different cities in Iran.
Published articles on the frequency of MRSE were collected from the Web of Science, PubMed, Scopus, Google Scholar, Cochrane Library, and Iranian databases from the beginning of 2016 to the end of 2020. Of the 503 records identified, 17 studies met the inclusion criteria, and their extracted data were analyzed using comprehensive meta-analysis version 2.0 (Biostat).
The analysis showed that the frequency of MRSE has decreased significantly in the last five years and reached 60.8 95% confidence interval (95% CI) 54.2-66.9 among culture-positive cases of
in Iran.
The noticeable reduction in the prevalence of MRSE in Iran could be due to the improvement of infection control programs and interruption of the pathogen transmission cycle. Another influential reason is the significant reduction in methicillin prescriptions by physicians for infections caused by staphylococci.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background. Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies and is considered the third major cause of mortality globally. Probiotics have been shown to protect ...against the CRC cascade in numerous studies. Aims. The goal of this systematic review was to gather the preclinical studies that examined the impact of probiotics on the alteration of gut microbiota profiles (bacterial communities) and their link to colorectal carcinogenesis as well as the potential processes involved. Methods. The search was performed using Scopus, Web of Science, and PubMed databases. Five parameters were used to develop search filters: “probiotics,” “prebiotics,” “synbiotics,” “colorectal cancer,” and “animal model.” Results. Of the 399 full texts that were screened, 33 original articles met the inclusion criteria. According to the current findings, probiotics/synbiotics could significantly attenuate aberrant crypt foci (ACF) formation, restore beneficial bacteria in the microbiota population, increase short-chain fatty acids (SCFAs), and change inflammatory marker expression. Conclusions. The present systematic review results indicate that probiotics could modulate the gut microbial composition and immune regulation to combat/inhibit CRC in preclinical models. However, where the evidence is more limited, it is critical to transfer preclinical research into clinical data.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
•Resistome analysis of 321 Lactobacillus genomic sequences derived from the human gut.•Identification of four high-frequency resistance genes, three of which were associated with acquired resistance, ...including poxtA (17.4%), lmrB (12%), and BJP-1 (7.7%).•The first report of BJP-1 in lactobacilli suggests that it is transferred from soil microbiota to humans.•Highlighting the ‘One Health’ perspective, early detection of a new reservoir would control the global spread of antibiotic resistance to other environments.
The gut is a complex environment inhabited by a wide range of bacterial species. Lactobacillus species constitute a significant proportion of this environment and, due to their mobile genetic elements such as plasmids and transposons, are more likely to acquire and transfer antibiotic resistance genes through horizontal gene transfer (HGT).
The current study obtained and analysed 321 genome assemblies to determine the prevalence of intrinsic and acquired antibiotic resistance genes (ARGs) among Lactobacillus species colonizing the human gastrointestinal tract.
A total of four high-frequency resistance genes were identified, including dfra42 (42%), poxtA (17.4%), lmrB (12%), and BJP-1 (7.7%); aside from dfra42, which is an intrinsic resistance gene, the other genes are acquired resistance genes. PoxtA was found in several different species, mainly in L. paracasei, whereas BJP-1 and lmrB were found in only one species, L. rhamnosus. IS5-like elements family transposase flanked 11% and 8% of detected lmrB and BJP-1, respectively, while a variety of insertion sequences surrounded 22% of identified poxtA. Furthermore, to the best of our knowledge, this is the first report of BJP-1 in lactobacilli that would suggest it has transferred from soil microbiota to humans.
According to the ‘One Health’ perspective, early detection of a new reservoir would control the global spread of the antibiotic-resistant bacterial species among the three environments, which include humans, the environment, and animals. Finally, the study's findings may then highlight the possibility of lactobacilli acquiring or transmitting resistance to other species within or outside the human intestine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP