Jundishapur Journal of Microbiology最新文献

{"title":"Expression of Biofilm-Related Genes in Extensively Drug-Resistant Acinetobacter baumannii","authors":"Maryam Khosravy, F. Hosseini, M. Razavi, Ramazan Ali Khavari","doi":"10.5812/jjm-133999","DOIUrl":"https://doi.org/10.5812/jjm-133999","url":null,"abstract":"Background: Acinetobacter baumannii is an important cause of nosocomial pneumonia in patients requiring long-term mechanical ventilation. Besides, extensively drug-resistant (XDR) strains cause infection in intensive care unit (ICU) patients. Chronic infections of A. baumannii and antimicrobial resistance are associated with biofilm formation. Several virulence genes, such as blaPER-1, pgaA, and bap, are involved in biofilm formation. Objectives: The current study examines the expression levels of biofilm formation-related genes in pneumonia patients. Methods: The sputum samples were collected from patients hospitalized in the ICU, and A. baumannii ATCC 19606, the reference strain, was isolated and cultured on blood agar, eosin methylene blue agar, and chocolate agar medium. The media were then incubated at 37°C for 18 - 24 hours. Next, Gram-Thirty XDR A. baumannii isolates were collected from the sputum samples of ICU patients at Besat Hospital in Tehran, Iran. Bacterial isolates were characterized for antibiotic resistance patterns and biofilm-forming ability. Subsequently, RNA was extracted from the biofilm-forming isolates. A real-time polymerase chain reaction (PCR) assay was performed to evaluate the expression levels of the blaPER-1, pgaA, and bap genes. Transcripts were normalized to 16S rRNA as an internal control, and gene expression fold changes were calculated. Statistical analysis was performed using an unpaired two-tailed t-test (P < 0.05) with SPSS (V. 16). Results: The disk diffusion susceptibility test revealed that all 30 (100%) isolates were resistant to piperacillin-tazobactam, cefepime, ceftriaxone, ceftazidime, gentamicin, imipenem, meropenem, levofloxacin, and ciprofloxacin. All 30 isolates from ICU-admitted patients (100%) were classified as XDR, and 27 (90%) isolates demonstrated the ability to form biofilms. The obtained results indicated a significant difference in gene expression levels. The fold change in expression for blaPER-1, bap, and pgaA was 7.473, 11.964, and 5.277, respectively. Conclusions: In our study, XDR A. baumannii primarily caused ventilator-associated pneumonia, and an observed increase in the expression of biofilm-related genes was noted in these strains. Healthcare centers should implement appropriate infection control programs to manage nosocomial infections, particularly in the ICU.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41278852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epidemiological Analysis and Effective Control of COVID-19 Outbreaks Caused by the Omicron Subvariant BA.2 in a Medium-sized City in China, 2022","authors":"Zhu Yang, Jinhong Zhao, Shuzhi Zhong, Yikun Wu, Bingjie Ye, Yiming Wang, Minmin Xiao","doi":"10.5812/jjm-136649","DOIUrl":"https://doi.org/10.5812/jjm-136649","url":null,"abstract":"Background: More and more variants of concern (VOCs) of SARS-CoV-2 continued to emerge in different regions worldwide. Objectives: Studies on COVID-19 outbreaks caused by different VOCs are critical for understanding their infections in humans in different regions. Methods: In this descriptive study, the individual information of 64 confirmed COVID-19 cases reported between March 3 and April 26, 2022, was collected, and the epidemiological features were analyzed. Results: We found COVID-19 epidemic caused by Omicron subvariant BA.2 in 2022 had unique characteristics compared to the earliest COVID-19 outbreaks in 2020 in Wuhu city. First, the geographic distribution of COVID-19 cases was highly concentrated, and most infections (58/64, 90.62%) were identified in one district in this study. Second, the mean age of COVID-19 cases in this study was 39.57 ± 16.39 years old, which was younger than the COVID-19 cases identified in Wuhan and Wuhu cities in 2020. Third, the spanned period of the COVID-19 outbreak in this study was shorter than the COVID-19 outbreak in 2020 in Wuhu city (13 days vs. 34 days). Conclusions: This study illustrates the epidemic of COVID-19 in Wuhu city from March to April 2022, and our result provides valuable information about COVID-19 outbreak caused by omicron subvariant BA.2. It also provides insights into developing effective strategies, such as high coverage of COVID-19 vaccination, lockdown policies, Ankang code, and population-bases COVID-19 screening, for successfully controlling the potential outbreaks caused by Omicron or future novel variants of SARS-CoV-2 in the medium-sized city like Wuhu.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44229519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the Presence of Efflux Pump Genes adeI and adeJ in Clinical Antibiotic-Resistant Isolates of Acinetobacter baumannii","authors":"Samaneh Ghafari, R. Mirnejad, Fatemeh Sameni, Mohamad Hoseyn Dehghan-Tarazjani, Mansoor Khaledi, M. Niakan","doi":"10.5812/jjm-135795","DOIUrl":"https://doi.org/10.5812/jjm-135795","url":null,"abstract":"Background: Acinetobacter baumannii is one of the most important known causes of hospital infections worldwide that is resistant to many common antibiotics. Efflux pumps are among the main reasons behind resistance in this bacterium. Objectives: This study was conducted to investigate the presence of efflux pump genes (adeI, adeJ) in clinical antibiotic-resistant isolates of A. baumannii in Tehran hospitals. Methods: One hundred fifty clinical samples of wounds, urine, sputum, and blood were collected periodically (6 months) from Tehran hospitals. A. baumannii was identified using common biochemical methods. After conducting biochemical tests, the final confirmation of the samples was performed by examining the blaOXA-51-like gene by molecular polymerase chain reaction (PCR) method. The disk diffusion antimicrobial susceptibility testing was performed using Mueller Hinton agar growth medium according to Clinical and Laboratory Standards Institute (CLSI) guidelines on nine antibiotics. Then the samples were investigated for the presence of adeI and adeJ genes. Results: Examining the antibiotic resistance of the isolates showed that the resistance level varied from 48.1% to 98.2%, depending on the antibiotic type. In this study, isolates showed the highest and lowest resistance to tetracycline and gentamicin, respectively. Also, positive isolates for the presence of adeI and adeJ genes showed the highest resistance to tetracycline, amikamycin, ceftazidime, and ceftriaxone. Isolates that were negative for the presence of these two genes showed the highest sensitivity to imipenem, gentamicin, and ciprofloxacin. Conclusions: In this study, the correlation of antibiotic resistance test and PCR results showed that the presence of adeI and adeJ genes in the samples significantly increased the resistance to all investigated antibiotics. Therefore, evaluating efflux pumps proves to be useful in identifying antibiotic-resistant strains and appropriate drug treatment. Of course, the role of other factors in creating resistance should not be neglected.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46986248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution of Class A Extended-Spectrum β-Lactamases Among Pseudomonas aeruginosa Clinical Strains Isolated from Ardabil Hospitals","authors":"Fereshteh Hasanpour, Nima Ataei, A. Sahebkar, F. Khademi","doi":"10.5812/jjm-135726","DOIUrl":"https://doi.org/10.5812/jjm-135726","url":null,"abstract":"Background: Currently, the emergence of extended-spectrum β-lactamase (ESBL)-producing bacteria is becoming a major threat to patients in the hospital and community. Such enzymes have been recently detected in Pseudomonas aeruginosa, but there is no epidemiological data on the prevalence of ESBL-producing clinical isolates in the hospitals of Ardabil City (Iran). Objectives: This study aimed to determine the phenotypic and genotypic prevalence of class A ESBL-producing P. aeruginosa strains in Ardabil City. Methods: A total of 120 clinical isolates of P. aeruginosa collected from Ardabil hospitals were used in this study. Phenotypic detection of class A ESBL-producing P. aeruginosa isolates was performed using a double-disk synergy test. In addition, the detection of class A ESBL-encoding genes, including Pseudomonas extended resistant (PER), Vietnamese extended-spectrum β-lactamase (VEB), temoniera (TEM), sulfhydryl variable (SHV), cefotaximase (CTX-M), guyana extended-spectrum β-lactamase (GES), and Pseudomonas-specific enzyme (PSE), was performed using the polymerase chain reaction (PCR). Results: The prevalence of class A ESBL-producing P. aeruginosa strains was 8.3% (10 out of 120) based on the double-disk synergy test. However, 40% (48 out of 120) of these isolates were found to carry genes encoding class A ESBLs based on PCR. Among 48 class A ESBL-positive strains, the prevalence of PSE, TEM, VEB, CTX-M, and PER genes were 64.6% (31/48), 25% (12/48), 4.2% (2/48), 4.2% (2/48), and 2% (1/48), respectively. However, the frequency of other class A ESBL genes (SHV and GES genes) was 0%. Conclusions: Our results confirmed the presence of class A ESBL-producing P. aeruginosa strains in the hospital environment of Ardabil. On the other hand, the use of molecular tests can be a more precise and reliable method than phenotypic ones to identify these resistant strains and prevent the emergence of antibiotic resistance and ensuing treatment failure.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43703876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of In Vitro Activity of Ceftolozane/Tazobactam and Ceftazidime/Avibactam Against Carbapenem-Resistant Pseudomonas aeruginosa Strains and Mechanisms of Carbapenem Resistance: Data from Tertiary Care Hospital","authors":"G. Hazırolan, Ceren Özkul","doi":"10.5812/jjm-134090","DOIUrl":"https://doi.org/10.5812/jjm-134090","url":null,"abstract":"Background: Carbapenem-resistant Pseudomonas aeruginosa is an endemic problem in several countries, notably Turkey. Objectives: This study aimed to investigate the underlying mechanisms contributing to the carbapenem resistance phenotype and enhance the in-vitro activity of ceftolozane-tazobactam (C/T) and ceftazidime-avibactam (C/A) against carbapenem-resistant P. aeruginosa strains. Methods: A total of 114 carbapenem-resistant P. aeruginosa strains were isolated from different types of clinical specimens. The tested antibiotics were evaluated using the antibiotic disk diffusion method. Additionally, C/T and C/A were tested using the gradient test method. The efficacy of phenylalanine-arginine-β-naphthylamide (PAβN) as efflux pump inhibitors was assessed to determine their ability to reduce meropenem minimum inhibitory concentrations. Polymerase chain reaction (PCR) assays were conducted to identify blaIMP, blaVIM, and blaNDM-1. Results: Among 114 strains of carbapenem-resistant P. aeruginosa, overall resistance rates for C/T and C/A were 10.7% and 8.8%, respectively. Efflux pump inhibitor-based antibiotic susceptibility testing indicated that 35.08% of strains showed resistance modulated by PAβN. Among the strains, 27 (24.5%) were found to produce metallo-beta-lactamase (MBL), with blaVIM (17 strains, 14.91%) being the most common, followed by blaIMP (12 strains, 10.53%). Conclusions: Emerging carbapenem resistance in P. aeruginosa strains is a serious therapeutic challenge for clinicians. Carbapenem resistance can be influenced by various factors, some of which were not assessed in our study. Nonetheless, our results revealed that the main mechanism associated with carbapenem-resistant P. aeruginosa strains is a PAβN-sensitive efflux pump. Among acquired MBLs, VIM-type enzymes were found to be the most prevalent.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47592191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serological Profile of SARS-CoV-2 in Unvaccinated Blood Donors: A Nationwide Study During the Fifth Wave of the Pandemic in Iran","authors":"Fahimeh Ranjbar Kermani, Peyman Eshghi, Mahtab Maghsudlu, Sedigheh Amini-Kafiabad, Amir Teimourpour, Mahmoud Reza Pourkarim","doi":"10.5812/jjm-135768","DOIUrl":"https://doi.org/10.5812/jjm-135768","url":null,"abstract":"Background: Serological studies can demonstrate pathogen circulation in regional populations and reflect public health measures' effectiveness during different pandemic phases. By late November 2021, coinciding with the third pandemic wave, the seroprevalence of SARS-CoV-2 spike IgG antibodies among the Iranian population was 32.63%. Objectives: This study aimed to assess the Iranian population's seroprevalence during the fifth pandemic wave by analyzing donated blood samples. Methods: This population-based cross-sectional study was conducted on Iranian blood donors referred to all 31 main provincial capitals between August 2021 and September 2021. The participants selected through quota sampling were asked to complete a questionnaire on socio-demographics and coronavirus disease 2019 (COVID-19)-related information. Also, SARS-CoV-2 spike IgG antibodies were measured in serum samples using SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA) kits. The seroprevalence was weighted based on the gender and age groups of the population and then adjusted for test performance. Results: Totally 3,339 blood donors participated in this study. The overall population-weighted seroprevalence adjusted for test performance was 52.67% (95% confidence interval (CI): 50.14 - 55.21). Seroprevalence was higher among participants with a high school diploma (55.45%, 95% CI 50.61 - 60.29), a positive history of close contact with COVID-19 patients (65.23%, 95% CI 60.83 - 69.63), and previous positive COVID-19 PCR tests (86.51%, 95% CI 82.32 - 90.7). Conclusions: More than half of the study population was exposed to SARS-CoV-2, indicating a 1.7-fold increase in the seroprevalence between late November 2020 and mid-September 2021. Our finding illuminated the pattern of Iran's fifth wave of the pandemic.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135691304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High Prevalence of Antiseptic Resistance Encoding Genes and Reduced Phenotypic Antiseptic Susceptibility Among Antibiotic-Resistant Pseudomonas aeruginosa Isolates","authors":"Mohadeseh Radmehr, M. Moghbeli, H. Ghasemzadeh-moghaddam, A. Azimian, A. van Belkum","doi":"10.5812/jjm-135911","DOIUrl":"https://doi.org/10.5812/jjm-135911","url":null,"abstract":"Background: Multi-drug resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa isolates are of clinical concern. Objectives: To determine the distribution of antiseptic resistance genes and the associated level of phenotypic antiseptic resistance against quaternary ammonium compounds and biguanide compounds, we studied MDR and XDR P. aeruginosa isolates collected from different infections among patients from a single hospital. Methods: Pseudomonas aeruginosa isolates were investigated in 2020 for in vitro susceptibility to benzethonium chloride (BTC), benzalkonium chloride (BKC), and chlorhexidine digluconate (CHG). The minimum inhibitory concentrations (MICs) against these antiseptic agents were determined using broth microdilution. Also, polymerase chain reaction (PCR)-mediated detection of qacE, qacEΔ1, and blaOXA-23 genes was used. Results: Isolates were largely non-clonal according to their phenotypical and genotypical non-similarity (35 overall data-combination types detected). Most P. aeruginosa infections occurred in intensive care unit (ICU) patients (n = 43, 61.4%). Extensively drug-resistant and MDR phenotypes were detected in 20% and 12.6%, respectively. Among the 70 isolates retained, 53 (75.7%) harbored at least one resistance gene, comprising 11 (20.7%) isolates with solely the qacEΔ1 gene; seven (13.2%) isolates harbored the qacE gene. Both the qacE and qacEΔ1 genes were detected simultaneously in 35 (66%) isolates. The mean MICs for BTC (24.0 versus 10.56 µg/mL), BKC (46.1 versus 17.22 µg/mL), and CHG (107.7 versus 29.4 µg/mL) were statistically significantly higher among antiseptic resistance gene harboring isolates than in other isolates without such genes. Conclusions: The significantly increased MICs against antiseptic agents among antibiotic-resistant P. aeruginosa isolates highlight the importance of monitoring such increases and implementing effective infection control.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46966195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of COVID-19 Mortality and Morbidity in Women Who Had Cesarean Sections and Terminated Pregnancies","authors":"Seyed Mohammad Amin Alavi, Saman Bahrami, Elham Kavousi, N. Saadati, M. Najafian","doi":"10.5812/jjm-133839","DOIUrl":"https://doi.org/10.5812/jjm-133839","url":null,"abstract":"Background: COVID-19 infection is a contemporary global concern with serious ramifications. This disease is caused by a virus belonging to the Coronaviridae family named SARS-CoV-2. Immunologic and physiologic changes during pregnancy make pregnant women more susceptible to viral infection, especially COVID-19. Objectives: The present study aimed to identify the clinical manifestations, radiologic findings, indications for cesarean delivery, underlying conditions, and the critical outcome of mothers and newborns regarding COVID-19 women who had cesarean sections and terminated pregnancies. Methods: This cross-sectional study was conducted on the mortality and morbidity rates of 98 women with terminated pregnancies infected with COVID-19 at the time of their cesarean delivery. The demographic, clinical, and pregnancy data were collected from Razi Teaching Hospital between March 2020 and March 2021 and analyzed using SPSS version 24. Results: The mean age was 31.31 ± 7.16, and the mean gestational age was 36.45 ± 3.334 weeks. The most prevalent cause of cesarean section was fetal distress (28%), followed by preeclampsia and meconium aspiration. The most common symptoms were sore throat, cough, fever, nausea, diarrhea, and weakness; moreover, hypothyroidism and diabetes mellitus were the most predominant underlying diseases. The mean duration for hospitalization was 5.21 ± 4.584 days, the maternal death rate was 5.1%, and the neonatal death rate was 2%. Conclusions: The majority of women infected with COVID-19 had cesarean sections and terminated pregnancies in the third trimester. This highlights the need for better care and education for mothers in this period. The body mass index (BMI) level and obesity are strongly associated with COVID-19 severity. Furthermore, healthcare workers should pay more attention to underlying diseases during pregnancy.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45332731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frequency of Extended-spectrum Beta-Lactamases-Producing Escherichia coli Among Out- and In-patients in Rafsanjan City, Iran","authors":"Ebrahim Rezazadeh Zarandi, H. Hakimi, R. Bahramabadi, M. Zare-Bidaki, M. Ramezani, Ali Shojaei, A. Khodayari, Maryam Fatemipour, Morteza Khademalhosseini, S. Assar","doi":"10.5812/jjm-133216","DOIUrl":"https://doi.org/10.5812/jjm-133216","url":null,"abstract":"Background: The frequency of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains among clinical isolates has been steadily increasing, leading to limited treatment options. Objectives: This study aimed to assess the antibiotic sensitivity of E. coli and the frequency of ESBL isolates among both out-patients and in-patients. Methods: A total of 390 E. coli isolates were received at the Ali-Ebn-e-Abitaleb Hospital laboratory in Rafsanjan. The antibiogram, as well as the phenotypic and genotypic detection of ESBL isolates, were conducted using Kirby-Bauer, combination disk confirmatory, and polymerase chain reaction tests, respectively. Results: Of all the E. coli isolates, 45.6% exhibited ESBL production. Among these isolates, 46.1% were obtained from hospital wards, while 42.5% were from outpatients. Meropenem and imipenem displayed sensitivities of 97.2% and 93.3%, respectively, whereas amikacin and nitrofurantoin showed sensitivities of 89.7% and 85.6%, respectively, for all isolates. Notably, ceftriaxone, cefotaxime, cefixime, ampicillin, co-trimoxazole, and nalidixic acid demonstrated high resistance rates, surpassing 50%. ESBL-producing isolates were more frequently observed in blood samples (65%) and wounds (60%) compared to other tested isolates. Approximately 8.6% of isolates carried a single type of ESBL gene, while 38.5% carried multiple ESBL genes. Conclusions: The data indicate a prevalence of ESBL-producing E. coli isolates among both out-patients and in-patients, with some of them acquiring two or three types of ESBL enzymes. As a result, their ability to hydrolyze antibiotics has increased, leading to their higher occurrence in clinical samples.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46547822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Synergistic Effect of LL-37 and Oncorhyncin II Recombinant Proteins on Staphylococcus aureus Under In Vitro Conditions","authors":"Mozhdeh Safari, Robab Rafiei Tabatabaei, H. Abtahi, A. Alimoradian, S. Fahimirad","doi":"10.5812/jjm-133963","DOIUrl":"https://doi.org/10.5812/jjm-133963","url":null,"abstract":"Background: The treatment of Staphylococcus aureus infections has become a public health crisis due to the extensive development of antimicrobial resistance. Antimicrobial peptides (AMPs) have been introduced as promising naturally-derived antimicrobial alternatives to antibiotics. LL-37 and oncorhyncin II are 2 AMPs with notable proven antibacterial effects. Objectives: This study aimed to produce recombinant LL-37 and oncorhyncin II and investigate their synergistic effects on S. aureus (ATCC25923). Methods: The synthetic genes of LL-37 and oncorhyncin II were individually ligated into the pET32a expression vector. Transformed pET32a was introduced into Escherichia coli BL21 as an expression host. The protein expression and purification steps were optimized, and the biological effectiveness of the peptides was evaluated by assessing the minimum inhibitory concentration (MIC), time-kill, and growth kinetic tests against S. aureus. Results: The MIC assay confirmed the effective antibacterial performances of LL-37 and oncorhyncin II against S. aureus at 30.6 and 47.93 µg/mL, respectively. The peptides’ synergistic activity was validated by the checkerboard method. A combination of LL-37 and oncorhyncin II at 2 × MIC showed a sharp decline of the viable cells with over 3-time reductions in log 10 colony-forming units (CFU)/mL within the first 5 hours. The growth kinetic results confirmed the high effectiveness of the peptides’ combination in eliminating the bacterial inoculum turbidity by 50% reduction during the first hour of exposure. Conclusions: The produced recombinant LL-37 and oncorhyncin II showed effective antimicrobial function against S. aureus. The synergistic performance of the peptides was repeatedly confirmed through checkerboard, time-kill, and growth kinetic assays.","PeriodicalId":17803,"journal":{"name":"Jundishapur Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48649279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}