Molecular characterization of Staphylococcus aureus isolated from hospital-acquired infections in Ilam, Iran.

OBJECTIVE: This research study was undertaken to investigate antimicrobial resistance patterns and the prevalence of hospital-acquired infections (HAIs). The study focuses on common microorganisms responsible for HAIs and explores emerging challenges posed by antimicrobial drug-resistant isolates. METHODS: A comprehensive analysis of 123 patients with HAIs, hospitalized in surgical department and intensive care unit (ICU) at Imam Khomeini Hospital, Ilam, Iran, was conducted over a six-month period. Pathogenic bacterial isolates, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA), were isolated and subjected to antibiotic susceptibility testing. RESULTS: The study findings revealed a significant prevalence of multidrug-resistant (MDR) isolates, of which 73.3% were MRSA. Notably, 6.7% of S. aureus isolates exhibited resistance to vancomycin, indicating the emergence of VRSA. Respiratory infections were identified as the most prevalent HAI, constituting 34.67% of cases, often arising from extended ICU stays and invasive surgical procedures. Furthermore, patients aged 60 and above, particularly those associated with MDR, exhibited higher vulnerability to HAI. CONCLUSIONS: This research sheds light on the intricate interplay between drug resistance and HAI, highlighting the imperative role of rational antibiotic use and infection control in addressing this critical healthcare challenge.

Nanomagnetic CoFe2O4@SiO2-EA-H3PO4 as a zwitterionic catalyst for the synthesis of bioactive pyrazolopyranopyrimidines and dihydropyrano[2,3-c]pyrazoles.

This study presents the development of a phosphoric acid-based zwitterionic catalyst immobilized on CoFe2O4 nanoparticles [CoFe2O4@SiO2-EA-H3PO4]. The structure of the nanocatalyst CoFe2O4@SiO2-EA-H3PO4 was identified by applying several spectroscopic techniques, i.e. FT-IR, SEM, TEM, XRD, EDX, elemental Mapping, VSM, TGA, and BET techniques. The catalytic efficiency of CoFe2O4@SiO2-EA-H3PO4 was evaluated in the water-based multicomponent synthesis of pyrazolopyranopyrimidine and dihydropyrano[2,3-c]pyrazole derivatives. Subsequently, an exploration of the antibacterial properties of the compounds was conducted. The catalytic system offers several advantages, encompassing high efficiency, brief reaction duration, uncomplicated operation, and facile recycling of the catalyst.

GNAT toxin may have a potential role in Pseudomonas aeruginosa persistence: an in vitro and in silico study.

Aims: Persistent cells are primarily responsible for developing antibiotic resistance and the recurrence of Pseudomonas aeruginosa. This study investigated the possible role of GNAT toxin in persistence. Materials & methods: P. aeruginosa was exposed to five MIC concentrations of ciprofloxacin. The expression levels of target genes were assessed. The GNAT/HTH system was bioinformatically studied, and an inhibitory peptide was designed to disrupt this system. Results: Ciprofloxacin can induce bacterial persistence. There was a significant increase in the expression of the GNAT toxin during the persistence state. A structural study of the GNAT/HTH system determined that an inhibitory peptide could be designed to block this system effectively. Conclusion: The GNAT/HTH system shows promise as a novel therapeutic target for combating P. aeruginosa infections.

Antibiotics are used to treat infections caused by bacteria. Over time, some of these infections have become more difficult to treat. This is because the bacteria can slow their growth and tolerate the antibiotic, known as persistence. It is important to find new ways to treat infections caused by persistent bacteria. This study researched a toxin­antitoxin system, called GNAT/HTH, that may play a role in bacterial persistence. This system could be a target for new antibiotics.

Effect of ZnO nanoparticles on biofilm formation and gene expression of the toxin-antitoxin system in clinical isolates of Pseudomonas aeruginosa.

BACKGROUND: Biofilm formation by Pseudomonas aeruginosa (P. aeruginosa) is known to be characteristic of this organism. This bacterium is considered one of the most life-threatening bacteria and has been identified as a priority pathogen for research by WHO. Biofilm-producing P. aeruginosa is a concern in many parts of the world due to antibiotic resistance. Alginate also plays an important role in the biofilm formation of P. aeruginosa as well as the emergence of antibiotic resistance in biofilms. In addition, the systems of toxin-antitoxin( TA) play an important role in biofilm formation. Metal nanoparticle(NP) such as zinc oxide (ZnO) also have extensive biological properties, especially anti-biofilm properties. Therefore, this study was conducted in relation to the importance of zinc oxide nanoparticles (ZnO NPs) in biofilm formation and also the correlation of gene expression of TA systems in clinical isolates of P. aeruginosa. METHODS: A total of 52 P. aeruginosa isolates were collected from burns (n = 15), UTI (n = 31), and trachea (n = 6) in hospitals in Ilam between May 2020 and October 2020. Biofilm formation was assessed using a microtiter plate assay. MIC and sub-MIC concentrations of ZnO NPs (10-30 nm with purity greater than 99.8%) in P. aeruginosa were determined. Subsequently, biofilm formation was investigated using sub-MIC concentrations of ZnO NPs. Finally, total RNA was extracted and RT- qPCR was used to determine the expression levels of genes of mazEF, mqsRA, and higBA of TA systems. RESULTS: Six isolates of P. aeruginosa were found to form strong biofilms. The results showed that ZnO NPs were able to inhibit biofilm formation. In our experiments, we found that the sub-MIC concentration of ZnO NPs increased the gene expression of antitoxins mazE and mqsA and toxin higB of TA systems treated with ZnO NPs. CONCLUSIONS: In the present study, ZnO NPs were shown to effectively inhibit biofilm formation in P. aeruginosa. Our results support the relationship between TA systems and ZnO NPs in biofilm formation in P. aeruginosa. Importantly, the expression of antitoxins mazE and mqsA was high after treatment with ZnO NPs, but not that of antitoxin higA.

Global Estimate of Clarithromycin Resistance in Clinical Isolates of Helicobacter pylori: a Systematic Review and Meta-Analysis.

BACKGROUND: A high resistance rate to clarithromycin usually leads to failure to eradicate Helicobacter pylori. The aim of the present study was to review recent data on H. pylori resistance towards clarithromycin in clinical studies worldwide. METHODS: PubMed/Medline, Web of Science, and Embase were used for a systematic review from 1 January 2011 to 13 April 2021 to retrieve the clinical trial studies. Data were analyzed according to publication year, age, geographic area, and minimum inhibitory concentration (MIC). Statistical analysis was done by STATA version 14.0 (College Station, Texas). RESULTS: From a total of 4,304 articles, 89 articles related to clinical studies were selected for analysis. The overall H. pylori clarithromycin resistance rate was 34.95%. Based on continents, the highest and lowest pooled estimate of the bacterial resistance rates were observed in Asia (35.97%) and North America (7.02%), respectively. The highest and the lowest pooled estimate of H. pylori resistance rate to clarithromycin based on country were obtained in Australia (93.4%) and USA (7%), respectively. CONCLUSIONS: H. pylori resistance to clarithromycin in most parts of the world is more than 15%, so it is recommended that each country, after estimating the rate of resistance to clarithromycin, determine the treatment/eradication pattern for H. pylori infection.

Nosocomial infections and antimicrobial susceptibility patterns among patients admitted to intensive care unit of Imam Khomeini hospital in Ilam, Iran.

INTRODUCTION: Nosocomial infections (NIs) are a major challenge worldwide. Identification of antibiotic resistance pattern extended spectrum beta-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) were the objectives of this study. METHODS: In this cross-sectional study, the antimicrobial susceptibility pattern of bacterial isolates collected from patients with NIs in ICU was determined. Overall, 42 Escherichia coli and Klebsiella pneumoniae isolates from different infection sites were used to determine phenotypic tests of ESBLs, Metallo-ß-lactamases (MBLs) and CRE. Detection of ESBLs, MBLs and CRE genes were performed by the polymerase chain reaction (PCR) method. RESULTS: From 71 patients with NIs, 103 different bacterial strains were isolated. The most frequently isolated bacteria were E. coli (n = 29; 28.16%), Acinetobacter baumannii (n = 15; 14.56%), and K. pneumoniae (n = 13; 12.26%). Also, the rate of multidrug-resistant (MDR) isolates was 58.25% (60/103). Based on phenotypic confirmation tests, 32 (76.19%) isolates of E. coli and K. pneumoniae produced ESBLs, and 6 (14.28%) isolates were identified as CRE producers. PCR showed the high prevalence of the blaCTX-M (n = 29; 90.62%) in ESBL genes. In addition, blaNDM was detected in 4 (66.66%), blaOXA-23 in 3 (50%), and blaOXA-48 gene in 1 (16.66%) isolates. The blaVIM, blaKPC, and blaIMP genes were not detected in any of the isolates. CONCLUSION: The Gram-negative bacteria E. coli, A. baumannii, and K. pneumoniae with high resistance levels were the most common bacteria causing NIs in the ICU. This study for the first time identified blaOXA-11, blaOXA-23, and blaNDM-1 genes in E. coli and K. pneumoniae in Ilam city of Iran.

Potential Role of Lactobacillus and Bifidobacterium for Preventing Kidney Stones.

BACKGROUND: A probiotic is a living microorganism that promotes host health when grown under appropriate conditions. Kidney stones are one of the universal agonizing diseases that have increased dramatically in recent years. One of the causes of this disease is hyperoxaluria (HOU), which is known to be an important factor in the formation of oxalate stones and is manifested by high levels of oxalate in the urine. In addition, about 80% of kidney stones contain oxalate, and decomposition of this material by microbes is one way to dispose of it. METHODS: Therefore, we examined a bacterial mixture containing Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, and Bifidobacterium longum to prevent of oxalate production in Wistar rats with kidney stones. We divided the rats into 6 groups defined in the method. RESULTS: The results of this study clearly show a decrease in urinary oxalate levels by exogenous means by L. plantarum, L. casei, L. acidophilus, and B. longum at the beginning of the experiment. Therefore, these bacteria can be used to control and prevent the formation of kidney stones. CONCLUSIONS: However, further studies should be conducted on the effects of these bacteria, and it is recommended to identify the gene responsible for the degradation of oxalate in order to develop a new probiotic.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis.

Background: Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics. Method: A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance. Results: The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I2 = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05). Conclusion: Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Amoxicillin-docosahexaenoic acid encapsulated chitosan-alginate nanoparticles as a delivery system with enhanced biocidal activities against Helicobacter pylori and improved ulcer healing.

Encapsulation of amoxicillin (AMX) for drug delivery against Helicobacter pylori infection and aspirin-induced ulcers in rat's stomachs was performed using docosahexaenoic acid (DHA)-loaded chitosan/alginate (CA) nanoparticles (NPs) developed by ionotropic gelation method. The physicochemical analyses of the composite NPs were performed by scanning electron microscopy, Fourier transform infrared spectroscopy, zeta potential, X-ray diffraction, and atomic force microscopy. The encapsulation efficiency of AMX was increased to 76% by incorporating DHA, which resulted in a reduction in the particle size. The formed CA-DHA-AMX NPs effectively adhered to the bacteria and rat gastric mucosa. Their antibacterial properties were more potent than those of the single AMX and CA-DHA NPs as demonstrated by the in vivo assay. The composite NPs attained higher mucoadhesive potential during food intake than during fasting (p = 0.029). At 10 and 20 mg/kg AMX, the CA-AMX-DHA showed more potent activities against H. pylori than the CA-AMX, CA-DHA, and single AMX. The in vivo study showed that the effective dose of AMX was lower when DHA was included, indicating better drug delivery and stability of the encapsulated AMX. Both mucosal thickening and ulcer index were significantly higher in the groups receiving CA-DHA-AMX than in the groups receiving CA-AMX and single AMX. The presence of DHA declines the pro-inflammatory cytokines including IL-1ß, IL-6, and IL-17A. The synergistic effects of AMX and the CA-DHA formulation increased the biocidal activities against H. pylori infection and improved ulcer healing properties.

Antimicrobial resistance and biofilm formation capacity among Acinetobacter baumannii strains isolated from patients with burns and ventilator-associated pneumonia.

BACKGROUND: Acinetobacter baumannii is a pathogen responsible for nosocomial infections, especially in patients with burns and ventilator-associated pneumonia (VAP). The aims of this study was to compare the biofilm formation capacity, antimicrobial resistance patterns and molecular typing based on PFGE (Pulsed-Field Gel Electrophoresis) in A. baumannii isolated from burn and VAP patients. MATERIALS AND METHODS: A total of 50 A. baumannii isolates were obtained from burn and VAP patients. In this study, we assessed antimicrobial susceptibility, biofilm formation capacity, PFGE fingerprinting, and the distribution of biofilm-related genes (csuD, csuE, ptk, ataA, and ompA). RESULTS: Overall, 74% of the strains were multidrug resistant (MDR), and 26% were extensively drug-resistant (XDR). Regarding biofilm formation capacity, 52%, 36%, and 12% of the isolates were strong, moderate, and weak biofilm producers. Strong biofilm formation capacity significantly correlated with XDR phenotype (12/13, 92.3%). All the isolates harbored at least one biofilm-related gene. The most prevalent gene was csuD (98%), followed by ptk (90%), ataA (88%), ompA (86%), and csuE (86%). Harboring all the biofilm-related genes was significantly associated with XDR phenotype. Finally, PFGE clustering revealed 6 clusters, among which cluster No. 2 showed a significant correlation with strong biofilm formation and XDR phenotype. CONCLUSION: Our findings revealed the variable distribution of biofilm-related genes among MDR and XDR A. baumannii isolates from burn and VAP patients. A significant correlation was found between strong biofilm formation capacity and XDR phenotype. Finally, our results suggested that XDR phenotype was predominant among strong-biofilm producer A. baumannii in our region.

Molecular Epidemiology and Recycling of Staphylococcus aureus Resistant to Methicillin Among the Staff, Patients, and Surfaces in University Hospital in West Iran, Ilam.

BACKGROUND: Staphylococcus aureus is a human pathogen causing nosocomial infections and increased hospitalization and mortality among human communities. Methicillin-resistant S. aureus strains are considered a severe threat in nosocomial infections and cause complications in the remedy process of bacterial infections. In this study, 137 samples were collected from different departments, staff, and patients in Ilam hospital. METHODS: Eighty-eight samples of these strains were examined to test antibiotic resistance and diffusion. MIC (minimum inhibitory concentration) and PCR (polymerase chain reaction) were performed on the samples resistant to oxacillin. 36 (40.9%) strains were MRSA, and 52 (59.1%) isolates were MSSA. 44.4% of MRSA strains with IV SCCmec type. RESULTS: Fourteen different spa types were found using spa typing, of which the most abundant types were t037, t030, and t701, and three new types, including t15471, t15474, and t17470, were identified among the strains. The molecular analysis by MLST showed that the strains are classified into 11 different sequence types. Sequence type 239 and clonal complexes of 329 and 22 were dominant. ST239- spat037-SCCmec III was also identified as the most frequent clone of MRSA. The most identified clones were MRSA ST239-spa t037-SCCmec III. CONCLUSION: The results show the spa-type distribution between samples of patients, personnel, and surfaces, demonstrating MRSA circulation between patients and the environment. The results show the need to control environmental health.

In silico Study of the Proteins Involved in the Persistence of Brucella spp.

BACKGROUND: One of the major problems with Brucella infections is its tendency to become chronic and recurrent, providing a hindrance to the management of this infection. It has been proposed that chronicity is greatly affected by a phenomenon called persistence in bacteria. Several mechanisms are involved in bacterial persistence, including the type II toxin-antitoxin system, the SOS and oxidative and stringent responses. METHODS: In this in silico study, these persistence mechanisms in Brucella spp. were investigated. RESULTS: The structure and the interactions between modules involved in these systems were designed, and novel peptides that can interfere with some of these important mechanisms were developed. CONCLUSION: Since peptide-based therapeutics are a new and evolving field due to their ease of production, we hope that peptides developed in this study, as well as the information about the structure and interactions of modules of persistence mechanisms, can further be used to design drugs against Brucella persister cells in the hope of restraining the chronic nature of Brucellosis.

Development of innovative multi-epitope mRNA vaccine against Pseudomonas aeruginosa using in silico approaches.

The rising issue of antibiotic resistance has made treating Pseudomonas aeruginosa infections increasingly challenging. Therefore, vaccines have emerged as a viable alternative to antibiotics for preventing P. aeruginosa infections in susceptible individuals. With its superior accuracy, high efficiency in stimulating cellular and humoral immune responses, and low cost, mRNA vaccine technology is quickly replacing traditional methods. This study aimed to design a novel mRNA vaccine by using in silico approaches against P. aeruginosa. The research team identified five surface and antigenic proteins and selected their appropriate epitopes with immunoinformatic tools. These epitopes were then examined for toxicity, allergenicity and homology. The researchers also checked their presentation and identification by major histocompatibility complex cells and other immune cells through valuable tools like molecular docking. They subsequently modeled a multi-epitope protein and optimized it. The mRNA was analyzed in terms of structure and stability, after which the immune system's response against the new vaccine was simulated. The results indicated that the designed mRNA construct could be an effective and promising vaccine that requires laboratory and clinical trials.

Molecular typing and antibiotic resistance patterns among clinical isolates of Acinetobacter baumannii recovered from burn patients in Tehran, Iran.

Acinetobacter baumannii (A. baumannii) is now considered a highly resistant pathogen to various types of antibiotics. Therefore, tracking the source of its prevalence and continuous control is crucial. This study aimed to determine antibiotic resistance and perform various molecular typing methods on clinical isolates of A. baumannii isolated from hospitalized burn patients in Shahid Motahari Burn Hospital, Tehran, Iran. Hospital isolates were confirmed by phenotypic and molecular methods. Then the sensitivity to different antibiotics was determined using the minimum inhibitory concentration (MIC) method. In order to perform molecular typing, three-locus dual assay multiplex polymerase chain reaction (PCR), multiple-locus variable-number tandem repeat analysis (MLVA), and multilocus sequence typing (MLST) methods were used. Among the 60 isolates collected, the frequencies of multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were 90 and 10%, respectively. The most effective antibiotics were colistin with 100% and tigecycline with 83.33% sensitivity. Isolates were 100% resistant to piperacillin/tazobactam and cephalosporins, and 68.3% were resistant to carbapenem. The results of multiplex PCR showed five groups that international clone I (IC I) and IC II were the most common. The MLVA method identified 34 MLVA types (MTs), 5 clusters, and 25 singletons. Multilocus sequence typing results for tigecycline-resistant isolates showed seven different sequence types (STs). Increasing antibiotic resistance in A. baumannii isolates requires careful management to control and prevent the occurrence of the pre-antibiotic era. The results of this study confirm that the population structure of A. baumannii isolates has a high diversity. More extensive studies are needed in Iran to better understand the epidemiology of A. baumannii.

Viral vector and nucleic acid vaccines against COVID-19: A narrative review.

After about 2 years since the first detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Wuhan, China, in December 2019 that resulted in a worldwide pandemic, 6.2 million deaths have been recorded. As a result, there is an urgent need for the development of a safe and effective vaccine for coronavirus disease 2019 (COVID-19). Endeavors for the production of effective vaccines inexhaustibly are continuing. At present according to the World Health Organization (WHO) COVID-19 vaccine tracker and landscape, 153 vaccine candidates are developing in the clinical phase all over the world. Some new and exciting platforms are nucleic acid-based vaccines such as Pfizer Biontech and Moderna vaccines consisting of a messenger RNA (mRNA) encoding a viral spike protein in host cells. Another novel vaccine platform is viral vector vaccine candidates that could be replicating or nonreplicating. These types of vaccines that have a harmless viral vector like adenovirus contain a genome encoding the spike protein of SARS-CoV-2, which induces significant immune responses. This technology of vaccine manufacturing has previously been used in many human clinical trials conducted for adenoviral vector-based vaccines against different infectious agents, including Ebola virus, Zika virus, HIV, and malaria. In this paper, we have a review of nucleic acid-based vaccines that are passing their phase 3 and 4 clinical trials and discuss their efficiency and adverse effects.

Clinical Manifestations, Imaging Procedures and Laboratory Parameters among Hospitalized Patients with COVID-19 in Ilam Province, Western Iran.

Background: COVID-19 is the last global threat which WHO confirmed it as a pandemic on March 11, 2020. In the Middle East, Iran was the first country where the SARS-Cov-2 was detected. The epidemiological and economic challenges of Iran make this country a particularly relevant subject of study. In the current study, we aimed to evaluate the clinical, radiological and laboratory findings in hospitalized COVID-19 confirmed cases in Ilam province, western of Iran. Methods: Overall, 2204 hospitalized RT-PCR confirmed patients with COVID-19 were considered in this study. Electronic medical records, including clinical symptoms, radiological images, laboratory findings, and the comorbidities of patients with COVID-19 were collected and analyzed. In addition, the medication regimens used in these patients were evaluated. The patients were classified in discharged and died groups according to their outcomes. Then, clinical, radiological and laboratory findings as well as treatment regimens and underlying diseases were compared in these two groups. Results: Among the patients, 1209 (54.85%) were male and 995 (45.14%) were female. Pneumonia, dyspnea and cough, were the most common clinical data in both discharged and died groups. Among the comorbidities, COPD, and cancer were significantly more common in the dead patients than in the living. The results of laboratory tests showed that blood creatinine, BUN, ESR, Na+, WBC, and neutrophil count have increased in deceased group compared to the survivors. However, the lymphocyte count decreased in deceased patients. The evaluation of radiographs demonstrated that there were significant correlations between bilateral pneumonia, ground glass opacity, bilateral patchy shadowing, and pleural effusion with death. Conclusion: The current investigation indicated the special profile of COVID-19 in west of Iran. Discharged and dead patients with COVID-19 had distinct clinical, radiological and laboratory features, which were separated by principal component analysis. Identifying these characteristics of the disease would translate into the implementation of practical measures to improve results.

The prevalence of gonococcal and non-gonococcal infections in women referred to obstetrics and gynecology clinics.

Bacterial vaginosis is a condition caused by changes in the vaginal microbial ecosystem and increases the risk of preterm delivery, premature rupture of membranes, endometritis, and weight loss of the baby. This study aimed to evaluate the frequency of gonococcal and non-gonococcal genital infections in women referred to clinics in Ilam, Iran. Two swab samples were taken from each patient using a sterile swab, one swab was placed in a THB medium for the culture of Streptococcus agalactiae and the other in PBS buffer for PCR. PCR method was conducted for the identification of the other bacterial agents such as Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, and also S. agalactiae. Sampling was performed on 169 women with symptomatic vaginosis. The frequency of S. agalactiae by culture and PCR methods was 4.7% (8 samples) and 13.6% (23 samples) respectively. Also, 6.5% (11 samples), 3.5% (6 samples), 4.1% (7 samples), 1.2% (2 samples), and 0% of the samples were positive for N. gonorrhoeae, M. genitalium, M. hominis, U. urealyticum and C. trachomatis by PCR method. Except for a significant association between S. agalactiae colonization and abortion, there was no significant correlation between the prevalence of these bacteria and the patient's age, age of marriage, number of deliveries, and number of abortions. Overall, the prevalence of gonococcal and non-gonococcal infection in women referred to clinics in Ilam is similar to the other parts of Iran.

Inhibitory Effects of Carvacrol on Biofilm Formation and Expression of Biofilm Related Genes in Clinical Isolates of Enterococcus faecalis.

BACKGROUND: Nowadays, novel antimicrobial strategies are being developed which focus on debilitating, rather than killing the microorganisms. In this regard, anti-biofilm therapy is one of the important ways to combat bacterial infections. Therefore, the aim of the current study was to evaluate the anti-biofilm activity of Carvacrol against E. faecalis by means of its effects on biofilm formation as well as on the gene expression levels of the two biofilm related genes, Epa and Esp. METHODS: A total of 40 clinical strains of E. faecalis were collected from three hospitals in Tehran, Iran during 2020. These isolates were confirmed by biochemical and genotypic methods. Antibacterial and anti-biofilm activity of Carvacrol essence were determined according the standard protocol. Finally, expression level of the biofilm related genes (Epa and Esp) were evaluated before and after the treatment with Carvacrol. RESULTS: A total of 14 isolates were considered as strong biofilm producers and were used for analysis. Carvacrol essence showed the best antibacterial activity at 2,500 µg/mL concentration against all the isolates, the biofilm formation capacity was decreased by Carvacrol essence, and it was statistically significant (p < 0.05). Expression levels of the Esp gene were decreased in 5 isolates while increased in 3 isolates following the Carvacrol treatment. Ex-pression levels of the EpaI gene was significantly decreased (p < 0.05) in 4 isolates following the Carvacrol treatment. CONCLUSIONS: In conclusion, the results presented in this study suggest that carvacrol extract exhibits significant antimicrobial and anti-biofilm properties against E. faecalis, even against vancomycin resistant isolates.

Heteroresistance to clarithromycin and metronidazole in patients with a Helicobacter pylori infection: a systematic review and meta-analysis.

BACKGROUND: Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection. MATERIAL AND METHODS: A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent. RESULTS: A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I2 = 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I2 = 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype. CONCLUSION: The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.

relBE toxin-antitoxin system as a reliable anti-biofilm target in Pseudomonas aeruginosa.

AIMS: The ability of the pathogenic bacterium Pseudomonas aeruginosa to produce biofilms has made it more difficult to treat its infections with current antibiotics. Several genes are involved in biofilm production, and toxin-antitoxin (TA) loci have been reported to be responsible for the regulation of biofilm-associated genes. This study was aimed at evaluating various TA loci in P. aeruginosa to find a reliable target in order to disrupt biofilm formation. METHODS AND RESULTS: Thirty clinical isolates of P. aeruginosa were assessed for biofilm production as well as the presence of various TA loci in their genomes. The relBETA locus was present in all 30 P. aeruginosa isolates but its expression was not detectable in isolates that did not show biofilm production. Quantitative real-time -PCR (q-PCR) also demonstrated that the expression of relBE was higher in isolates with stronger biofilm-producing capability. Knocking out the relBE locus in one biofilm-producing P. aeruginosa isolate led to the cessation of biofilm-producing capacity in that isolate and eliminated the expression of ndvB, which is among the genes involved in biofilm production. CONCLUSIONS: These results inferred the involvement of relBE TA locus in the regulation of biofilm production in P. aeruginosa and indicated the possibility of relBE as an anti-biofilm target for this pathogen.