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The carbapenem-resistant Enterobacterales (CRE) pose a pressing public health concern. Here, we investigated the frequency of CRE bacteria, carbapenemase-encoding genes, and the molecular epidemiology of carbapenemase-resistant Escherichia coli in wastewater resources and healthy carriers in Iran. Out of 617 Enterobacterales bacteria, 24% were carbapenem-resistant. The prevalence of CRE bacteria in livestock and poultry wastewater at 34% and hospital wastewater at 33% was significantly higher (P ≤ 0.05) than those in healthy carriers and municipal wastewater at 22 and 17%, respectively. The overall colonization rate of CRE in healthy individuals was 22%. Regarding individual Enterobacterales species, the following percentages of isolates were found to be CRE: E. coli (18%), Citrobacter spp. (24%), Klebsiella pneumoniae (28%), Proteus spp. (40%), Enterobacter spp. (25%), Yersinia spp. (17%), Hafnia spp. (31%), Providencia spp. (21%), and Serratia spp. (36%). The blaOXA-48 gene was detected in 97% of CRE isolates, while the blaNDM and blaVIM genes were detected in 24 and 3% of isolates, respectively. The B2 phylogroup was the most prominent group identified in carbapenem-resistant E. coli isolates, accounting for 80% of isolates. High prevalence of CRE with transmissible carbapenemase genes among healthy people and wastewater in Iran underscores the need for assertive measures to prevent further dissemination. HIGHLIGHTS Twenty-four percent of isolates, including nine species, were carbapenem-resistant.; CRE bacteria were widely distributed in various wastewater resources and healthy individuals.; CRE bacteria were more prevalent in hospital, livestock, and poultry wastewater.; The blaOXA-48 gene was detected in 97% of CRE isolates, followed by blaNDM, 24%, and blaVIM, 3%.; Carbapenem-resistant E. coli isolates mainly belonged to the B2 phylogroup.;

Abstract Background Pseudomonas aeruginosa is a common cause of nosocomial infections. However, the emergence of multidrug-resistant strains has complicated the treatment of P. aeruginosa infections. While polymyxins have been the mainstay for treatment, there is a global increase in resistance to these antibiotics. Therefore, our study aimed to determine the prevalence and molecular details of colistin resistance in P. aeruginosa clinical isolates collected between June 2019 and May 2023, as well as the genetic linkage of colistin-resistant P. aeruginosa isolates. Results The resistance rate to colistin was 9% (n = 18) among P. aeruginosa isolates. All 18 colistin-resistant isolates were biofilm producers and carried genes associated with biofilm formation. Furthermore, the presence of genes encoding efflux pumps, TCSs, and outer membrane porin was observed in all colistin-resistant P. aeruginosa strains, while the mcr-1 gene was not detected. Amino acid substitutions were identified only in the PmrB protein of multidrug- and colistin-resistant strains. The expression levels of mexA, mexC, mexE, mexY, phoP, and pmrA genes in the 18 colistin-resistant P. aeruginosa strains were as follows: 88.8%, 94.4%, 11.1%, 83.3%, 83.3%, and 38.8%, respectively. Additionally, down-regulation of the oprD gene was observed in 44.4% of colistin-resistant P. aeruginosa strains. Conclusion This study reports the emergence of colistin resistance with various mechanisms among P. aeruginosa strains in Ardabil hospitals. We recommend avoiding unnecessary use of colistin to prevent potential future increases in colistin resistance.

Background: Antibiotic resistance represents a critical global concern within the medical community, posing significant challenges in the treatment of infections caused by drug-resistant pathogens. Over the years, broad-spectrum fluoroquinolones have been extensively used to treat infections caused by both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa. In this study, we decided to assess the prevalence of plasmid-mediated quinolone resistance mechanisms among clinical isolates of P. aeruginosa in Ardabil hospitals. Methods: We analyzed a total of 200 clinical isolates of P. aeruginosa, collected between June 2019 and May 2023. The antibiotic resistance profiles of these strains against various fluoroquinolone antibiotics were determined using the disk diffusion method. Additionally, we investigated the presence of qnrA, qnrB, qnrC, qnrD, and qnrS genes through polymerase chain reaction (PCR) analysis. Furthermore, we assessed the expression levels of efflux pump genes and outer membrane porin genes using the quantitative reverse transcription PCR (qRT-PCR) in fluoroquinolone-resistant P. aeruginosa strains. Results: Our findings revealed that 69% of P. aeruginosa strains were resistant to fluoroquinolones. The resistance rates for different fluoroquinolones were as follows: ciprofloxacin 55.5%, ofloxacin 62%, norfloxacin 53.5%, lomefloxacin 55.3%, and levofloxacin 55.5%. Notably, 78.9% of these strains exhibited multidrug resistance (MDR). Among the qnr genes, qnrB was the most prevalent (2.9%). No other qnr genes were identified. Interestingly, 75% of P. aeruginosa strains carrying the qnrB gene showed overexpression of efflux pump genes, while 100% exhibited down-regulation of the oprD gene. Conclusion: Given the high prevalence of fluoroquinolone-resistant P. aeruginosa clinical isolates in Ardabil hospitals and the multifactorial nature of resistance, continuous monitoring of antibiotic resistance trends and understanding the underlying resistance mechanisms are crucial for selecting appropriate treatment strategies.

Hospital wastewater can contaminate the environment with antibiotic-resistant and virulent bacteria. We analyzed wastewater samples from four hospitals in Ardabil province, Iran for Enterococcus faecium and Enterococcus faecalis using culture and molecular methods. We also performed antimicrobial susceptibility testing and polymerase chain reaction testing for resistance and virulence genes. Out of 141 enterococci isolates, 68.8% were E. faecium and 23.4% were E. faecalis. Ciprofloxacin and rifampicin showed the highest level of resistance against E. faecalis and E. faecium isolates at 65%. High-level gentamicin resistance (HLGR), high-level streptomycin resistance (HLSR), ampicillin, and vancomycin resistance were observed in 25, 5, 10, and 5.15% of E. faecium, and 15, 6, 15, and 3.03% of E. faecalis isolates, respectively. The ant(6′)-Ia and ant(3′)-Ia genes that were responsible for streptomycin resistance were observed in HLSR isolates and aph(3′)-IIIa and aac(6′) Ie-aph(2″)-Ia genes accounting for gentamicin resistance were detected in HLGR isolates. vanA was the predominant gene detected in vancomycin-resistant isolates. The majority of isolates were positive for gelE, asa1, esp, cylA, and hyl virulence genes. We found that drug-resistant and virulent E. faecalis and E. faecium isolates were prevalent in hospital wastewater. Proper treatment strategies are required to prevent their dissemination into the environment. HIGHLIGHTS The prevalence of E. faecium isolates in hospital wastewater was three times higher than that of E. faecalis isolates.; Five percent of E. faecium and 3% of E. faecalis isolates were vancomycin-resistant.; The rate of HLSR was almost four times the rate of HLGR among Enterococcus spp.; Almost all of the isolates were multidrug-resistant.; The majority of E. faecalis and E. faecium isolates contained multiple virulence genes simultaneously.;

Abstract Background This study was aimed to evaluate the prevalence and molecular characteristics of ciprofloxacin resistance among 346 Escherichia coli isolates collected from clinical specimens (n = 82), healthy children (n = 176), municipal wastewater (n = 34), hospital wastewater (n = 33), poultry slaughterhouse wastewater (n = 12) and livestock (n = 9) slaughterhouse wastewater in Iran. Methods Ciprofloxacin minimum inhibitory concentration (MIC) was determined by agar dilution assay. Phylogroups and plasmid-mediated quinolone resistance (PMQR) genes were identified using PCR. Mutations in gyrA, gyrB, parC, and parE genes and amino acid alterations were screened through sequencing assay. The effect of efflux pump inhibitor (PAβN) on ciprofloxacin MICs in ciprofloxacin-resistant isolates was investigated using the microdilution method. Results In total, 28.03% of E. coli isolates were phenotypically resistant to ciprofloxacin. Based on sources of isolation, 64.63%, 51.51%, 33.33%, 14.70%, 10.22% and 8.33% of isolates from clinical specimens, hospital wastewater, livestock wastewater, municipal wastewater, healthy children and poultry wastewater were ciprofloxacin-resistant, respectively. Eighty-one point eighty-one percent (Ser-83 → Leu + Asp-87 → Asn; 78.78% and Ser-83 → Leu only; 3.03% (of ciprofloxacin-resistant E. coli isolates showed missense mutation in GyrA subunit of DNA gyrase, while no amino-acid substitution was noted in the GyrB subunit. DNA sequence analyses of the ParC and ParE subunits of topoisomerase IV exhibited amino-acid changes in 30.30% (Ser-80 → Ile + Glu-84 → Val; 18.18%, Ser-80 → Ile only; 9.10% and Glu-84 → Val only; 3.03%0 (and 15.38% (Ser-458 → Ala) of ciprofloxacin-resistant E. coli isolates, respectively. The PMQR genes, aac(6')-Ib-cr, qnrS, qnrB, oqxA, oqxB, and qepA were detected in 43.29%, 74.22%, 9.27%, 14.43%, 30.92% and 1.03% of ciprofloxacin-resistant isolates, respectively. No isolate was found to be positive for qnrA and qnrD genes. In isolates harboring the OqxA/B efflux pump, the MIC of ciprofloxacin was reduced twofold in the presence of PAβN, as an efflux pump inhibitor. The phylogroups B2 (48.45%) and A (20.65%) were the most predominant groups identified in ciprofloxacin-resistant isolates. Conclusions This study proved the high incidence of ciprofloxacin-resistant E. coli isolates in both clinical and non-clinical settings in Iran. Chromosomal gene mutations and PMQR genes were identified in ciprofloxacin resistance among E. coli population.

Background and purpose: Antibacterial properties of restorative materials are of great advantage as they control the progression of tooth decay. The use of self-adhesive composite materials has some benefits such as easier application and reduced treatment time. Because the antibacterial properties of restorative materials can play an important role in preventing secondary decay, especially in cervical restorations, this study was designed to evaluate the in vitro antibacterial activity of self-adhesive flowable composite against Streptococcus mutans. Materials and methods: An in vitro study was performed using 9 discs for each composite and glass ionomer group. The discs were prepared in three groups: micro-hybrid flowable composite samples, self-adhesive flowable composite samples, and self-curing glass ionomer samples. Direct contact test was used to compare the antibacterial properties of the discs. Data collection was done by direct contact test and visual counting of grown bacterial colonies. Data were recorded in a checklist developed according to the objectives of the study and analyzed using One-way ANOVA and Independent T-test in SPSS V22. Results: Findings showed that the antibacterial effect of glass ionomer was greater than that of flowable micro-hybrid composite and self-adhesive flowable composite. Also, a significant difference was observed between the antimicrobial activity of flowable microhybrid composite and self-adhesive flowable composite against Streptococcus mutans (P

The prevalence, antibiotic resistance, and virulence characteristics of Staphylococci from hospitals, livestock, municipals, and poultry wastewaters were investigated in Ardabil, Iran. From 155 staphylococcal isolates, 44.5% were coagulase-positive Staphylococcus (CoPS) and 55.5% were coagulase-negative Staphylococcus (CoNS) spp. Both CoPS and CoNS species were mainly found in hospital and poultry wastewater samples. The most prominent CoPS and CoNS species were Staphylococcus aureus at 80% and Staphylococcus xylosus at 37%. Methicillin resistance was found in 2% of S. aureus isolates. Overall, 49.2% of CoPS and 47.6% of CoNS isolates exhibited multidrug resistance phenotypes. CoPS isolates were the most resistant to penicillin (89%) and erythromycin (62%) and CoNS isolates exhibited the highest resistance to erythromycin (55%) and tetracycline (49%). Inducible clindamycin resistance was detected in 11% of S. aureus isolates. The ermC and aac genes were detected as the most common macrolide–lincosamide–streptogramin B and aminoglycoside-resistance encoding genes in 82.5 and 22.5% of S. aureus isolates, respectively. Most of the S. aureus isolates were positive for multiple virulence factors. The methicillin-resistant S. aureus isolates belonged to SCCmec type V. A new spa type t19215 was also identified. The occurrence of multidrug-resistant S. aureus with diverse genetic resistance and virulence background in wastewater is of great health concern. HIGHLIGHTS Ten coagulase-negative and four coagulase-positive Staphylococcus spp. were identified in wastewaters in Iran.; 50% of both coagulase-negative and coagulase-positive Staphylococcus spp. isolates were multidrug-resistant.; Occurrence of methicillin-resistant S. aureus was rare in wastewater samples in Iran.; S. aureus isolates with high virulence potentials were common.; A new spa type t19215 was identified in S. aureus isolates.;

Abstract Background and Aims Klebsiella pneumoniae is a Gram‐negative bacterium that colonized various organs. This bacterium is associated with different community‐acquired and hospital‐acquired infections. The present study aims to assess the capsular serotypes and frequency of virulence‐associated genes in K. pneumoniae isolates from teaching hospitals in Ardabil, Iran. Methods From October 1, 2019, to November 31, 2021, different clinical samples were collected and K. pneumoniae isolates were diagnosed using conventional biochemical tests. The final identification of K. pneumoniae was performed through the polymerase chain reaction (PCR) method using a specific primer targeting the khe gene. The PCR method was employed to confirm the presence of virulence‐associated genes and aerobactin, and the main capsular serotypes based on the specific primers. Results Of all 100 K. pneumoniae isolates, 4% and 2% were typeable with K5 and K2 primers, respectively. In addition, entB (94%), fimH (91%), and wcaG (87%) had the highest frequency among the virulence‐associated genes. 24% of K. pneumoniae isolates harbored the entB‐wcaG‐fimH genes simultaneously. Moreover, 50% of capsular serotype 5 harbored the ybts‐mrkD‐entB‐wcaG‐fimH genes simultaneously. Conclusion The findings revealed that 6% of all K. pneumoniae isolates were typeable, distributed in the two serotypes K5 and K2. Most K. pneumoniae isolates were positive for multiple types of virulence genes. Identifying bacterial virulence genes aids in molecular detection, assay development, and therapeutic pathways.

Background and Objectives: he occurrence and characteristics of Extended Spectrum- and AmpC-β-lactamase producing Enterobacterales (ESBL-PE and AmpC-PE) in an urban wastewater treatment plant (WWTP) were investigated. Materials and Methods: A total of 30 wastewater samples were collected from all sections of WWTP. Enterobacterales were isolated and identified using standard microbiological tests. The antibiotic resistance profile was determined by the Kirby–Bauer disk diffusion method. Phenotypic screening for ESBL-PE and AmpC-PE isolates was performed by double-disk synergy and boronic acid disk potentiation tests, respectively. The isolates were examined for AmpC- and ESBL-encoding genes by PCR and sequencing methods. Results: Among 146 Enterobacterales isolates, 8.9% (n=13) [ESBL-only; 5.48% (n=8) and ESBL + AmpC; 3.42% (n=5)] were ESBL-producers and 15.75% (n=23) [AmpC-only; 12.33% (n=18) and ESBL + AmpC; 3.42% (n=5)] AmpC-producers. Hafnia spp. with 33.33% (n=1/3) and E. coli with 20.58% (n=7/34) [ESBL-only; 17.64% (n=6/34) and ESBL + AmpC; 2.94% (n=1/34)] were the most common ESBL-producing bacteria. Enterobacter spp. with 37.50% (n=6/16) of isolates were the most common AmpC-producing organisms. ESBL- and/or AmpC-producing isolates were identified in all parts of the WWTP including 80% (n=8/10) of samples taken from effluent. Among ESBL-producing isolates, blaCTX-M, blaTEM, and blaSHV ESBL-encoding genes were found in 61.5% (n=8), 15.3% (n=2), and 7.7% (n=1) of isolates, respectively. All CTX-M-type enzymes belonged to the CTX-M-1 group and CTX-M-15 subgroup. blaTEM and blaSHV type genes belonged to blaTEM-20 and blaHSV-12 subtypes, respectively. blaDHA with 73.9% (n=17/23), and blaCIT and blaFOX with 30.4% (n=7/23) each, were the most common AmpC-encoding genes among AmpC-producing isolates. Overall, 75% of ESBL-producing and 55.5% of AmpC-producing isolates exhibited multi-drug resistance phenotypes. The organisms were most resistant against ampicillin (82.2%) nalidixic acid (43.8%) and cephalexin (41.1%). Conclusion: ESBL- and AmpC-producing Enterobacterales spp. with diverse genetic resistance backgrounds in WWTP effluent poses a significant risk to public health.

Background and Objective: Integrons play an essential role in disseminating drug resistance genes among bacteria. The aim of this study was to determine the prevalence of integrons, and Extended-Spectrum β-Lactamase (ESBL) genes in Escherichia coli (E. coli) isolates collected from patients with urinary tract infection (UTI) referred to teaching hospitals in Ardabil, Iran. Materials and Methods: In this descriptive, cross-sectional study (2017-2018), 163 isolates of E.coli were collected from patients with UTI. The drug susceptibility pattern of these isolates to 12 common antibiotics was investigated using the disk diffusion method based on CLSI guidelines. The prevalence of class 1, 2 ,3 integrons and ESBL genes was verified by the PCR method. Finally, the genetic variation of isolates was analyzed using the ERIC-PCR method. Results: Of 163 isolates, 138 (84.7%) isolates were multidrug-resistance (MDR) strains. The lowest and highest antibiotic resistance was reported to nitrofurantoin and ampicillin, with a resistance rate of 1.2% and 89.6%, respectively. The incidence of class 1 and 2 integrons was obtained in 39.9% and 14.1% of the isolates, respectively. Class 3 integron was not found in any of the isolates. Based on the ERIC-PCR fingerprinting method, 4 ERIC types were detected. Conclusion: Our study showed that E. coli isolates taken from patients mainly were MDR strain and resistant to many of the common antibiotics used to treat urinary tract infections. Using the correct dose of medication and multidrug therapy would be effective in reducing the incidence of antibiotic resistance.

Background & Aims: Acinetobacter baumannii is one of the most important pathogenic bacteria causing nosocomial and opportunistic infection with the high rate of antibiotic resistance. The aim of the present work was to study the antimicrobial resistance pattern of Acinetobacter isolates recovered from patients admitted to Imam Khomeini Hospital and identifying the related risk factors. Also, in this study, the efficacy of different combined antimicrobial therapy against A. baumannii was evaluated. Materials & Methods: In this retrospective study, a total of 108 medical records related to patients admitted to Imam Khomeini Hospital in Ardabil province from 2011 to 2013 was entered into the study. For each patient, demographic, bacterial culture, and antibiogram data were obtained and analyzed. Results: Results indicated that pulmonary infections were the most common clinical source of Acinetobacter infection. The highest rate of resistance (100%) was related to ceftizoxime, chloramphenicol, furazolidone, nitrofurantoin, cephalothin, cephalexin, ticarcillin, piperacillin, amoxicillin, and aztreonam followed by ceftazidime, imipenem, co-trimoxazole, ceftriaxone, cefotaxime, and cefixime (80%). The lowest rate of resistance was seen against polymyxin B, ampicillin/sulbactam and meropenem. Our results indicated that 86.9 % and 91.7% of isolates were resistant to ceftriaxone and imipenem, respectively. Since carbapenems are the drug of choice and the last-resort agent for the treatment of MDR strain of A. baumannii , this high resistance level would be a serious concern. Conclusion: The epidemiological survey will be helpful in controlling infections in hospital environment and prescribing proper antimicrobial agents.

Objectives: High-level aminoglycoside, ampicillin and vancomycin resistance and virulence genes among enterococcal isolates collected from healthy middle-school children in Ardabil, Iran, during 2016 were investigated. Methods: Totally, 305 faecal specimens were collected. Isolates underwent antimicrobial susceptibility testing, virulence gene detection and molecular typing. Results: Totally, 409 enterococcal isolates were collected, comprising Enterococcus faecium (235; 57.5%), Enterococcus faecalis (56; 13.7%) and other Enterococcus spp. (118; 28.9%). Overall, 71 (17.4%), 11 (2.7%) and 10 (2.4%) isolates were identified as high-level streptomycin-resistant (HLSR), high-level gentamicin-resistant (HLGR) and ampicillin-resistant (AR), respectively. Among HLSR isolates, 40 (56.3%), 5 (7.0%) and 26 (36.6%) were E. faecium, E. faecalis and other Enterococcus spp., respectively. Among HLGR isolates 4 (36.4%) and 7 (63.6%) and among AR isolates 7 (70.0%) and 3 (30.0%) were E. faecium and other Enterococcus spp., respectively. Accordingly, 21.6%, 3.6% and 3.3% of subjects were colonised with HLSR, HLGR and AR Enterococcus spp. Carriage of HLGR, HLSR and AR isolates was associated with prior antibiotic consumption (P ≤ 0.05). Additionally, male sex and antacid consumption were associated with AR enterococcal carriage. Moreover, 69 (97.2%), 10 (90.9%) and 9 (90.0%) of HLSR, HLGR and AR isolates were multidrug-resistant, respectively. No vancomycin-resistant enterococci were detected. ERIC-PCR revealed high genetic diversity among isolates. gelE and asa1 were major virulence genes both in E. faecalis and E. faecium. Presence of gelE was associated with HLSR and HLGR phenotypes (P ≤ 0.05). Conclusion: Community intestinal carriage of HLSR enterococci was high; however, carriage of HLGR and AR enterococci was low.

Background and Aim: One of the major purposes of pediatric dentistry is to maintain deciduous teeth in anatomical and functional conditions up to their physiological exfoliation and eruption of permanent teeth. Whenever pulp gets involved or exposed to mouth area and microorganisms penetrate into pulp, deciduous teeth needs pulp therapy. In the sterile environment, the exposed pulp tissue is able to repair itself and also to create a dentin bridge, but in the presence of bacteria, development of disease and ultimately death of the pulp will be inevitable. The ideal pulpotomy cement should have good physical and biological properties such as sealing of the remaining pulp tissue, being biocompatible and possessing antibacterial activity. The aim of this study was to compare the antibacterial effect of some usual materials used for pulpotomy in deciduous teeth. Materials and Methods: In this study, we evaluated the antibacterial activity of materials used in deciduous teeth pulpotomy including Zoliran, Sina Zonalin, Kemdent Zonalin, MTA (OrthoMTA) and CEM Cement against Streptococcus mutans and Lactobacillus acidophilus. Well diffusion test and disk diffusion test and time kill curve were used for antibacterial activity assay. Also, we evaluated stability of antibacterial activity of the materials. The antibacterial activity in disk diffusion and well diffusion test was measured based on the diameter of the zone of inhibition, whereas in time kill curve the optical density of the bacterial suspension was measured. We used analysis of variance (ANOVA) and Tukey’s test at the significance level of 5% . Results: In well diffussion and disk diffussion tests all of the materials except CEM Cement showed antibacterial activity against Streptococcus mutans and Lactobacillus acidophilus. The largest and smallest zones of inhibition belonged to zoliran and MTA respectively. The results of time kill curve revealed a similar pattern, so that during the experiment period Zoliran, Sina Zonalin, Kemdent Zonalin, MTA and CEM Cement showed the greatest effects in both groups of bacteria respectively. Conclusion: Reinforced ZOE groups had the greatest effect in inhibition of growth of S.mutans and L.acidophilus compared to MTA and CEM Cement. Thus, use of Zoliran, Sina and Kemdent Zonalin cements in pulpotomy of deciduous teeth can be useful in controlling bacterial growth and achieving success in pulpotomy.

Background and Objectives: Nowadays, high-level aminoglycosides and ampicillin resistant Enterococcus species are among the most common causes of nosocomial infections. The present study was conducted to determine the prevalence of high-level resistance to aminoglycosides and ampicillin among clinical isolates of Enterococcus species in Ardabil, Iran. Materials and Methods: In this cross–sectional study, a total of 111 Enterococcus species were collected from different clinical specimens between 2013 and 2015. Enterococcus species were identified using standard phenotypic and genotypic methods. BHI agar screen and agar dilution methods were used for detection of high-level gentamicin and streptomycin resistance (HLGR and HLSR) and minimal inhibitory concentration (MIC) of ampicillin, respectively. Results: Of 111 clinical isolates, 59 (53.2%) and 25 (22.5%) isolates were E. faecalis and E. faecium, respectively, based on the PCR results. Totally, 60.3% and 56.7% of isolates were HLGR and HLSR, respectively, as well as 51.35% were HLGR plus HLSR. Among HLGR isolates, 36 (61.01%), 18 (72%) and 13 (48.14%) were E. faecium, E. faecalis and non-faecalis non-faecium species, respectively. Among HLSR isolates, 33 (55.93%), 16 (64%) and 14 (51.85%) were E. faecalis, E. faecium and non-faecalis non-faecium species, respectively. All HLGR isolates contained aac(6´)Ie-aph(2″)Ia gene. Overall, the prevalence of high-level ampicillin resistance among Enterococcus species was 17.1%. For E. faecalis, E. faecium and non-faecalis non-faecium species, ampicillin resistance rates were as follows: 11 (40.74%), 7 (28%) and 1 (1.69%), respectively. For aminoglycoside antibiotics, the resistance rate was significantly higher in E. faecium isolates and for ampicillin it was higher in E. faecalis isolates. Conclusion: The frequency of high-level aminoglycoside resistant enterococcal isolates in our hospital was high and significant ampicillin resistance was noticed. This would require routine testing of enterococcal isolates for HLAR and ampicillin susceptibility.

Background and Objectives: Shigella is an etiological agent of shigellosis. Antibiotic therapy has a critical role in decreasing serious complications of shigellosis. The present study aimed to determine the multi-drug resistance strains and to detect fluoroquinolone related mutations. Materials and Methods: In this descriptive, cross sectional study, a total of 113 Shigella isolates were collected from 1280 patients admitted to Bu-Ali hospital in Ardabil province during 2015-17. Antibiotic resistance pattern of isolates was evaluated using Kirby Bauer method and finally, the MICs of ciprofloxacin were determined. In order to determine any mutations in QRDR region, parC and gyrA genes of resistant strains were amplified and sequenced. Results: Shigella spp. isolates were identified using ipaH amplification and rfc and wbgz genes were used for molecular detection of S. flexneri and S. soneii, respectively. Our results showed that the predominant species in Ardabil province was S. sonnei (69.91%). Most of isolates (82%) were resistant to trimethoprim/sulfamethoxazole (TMP/SMX); 51% were nalidixic acid resistant and 4.4% were floroquinolones resistant. All examined isolates were susceptible to imipenem (100%). Mutation in gyrA and parC genes were detected in all fluoroquinolone resistant isolates (5 isolates). Although, in this study the rate of resistance to ciprofloxacin was low, but in the lack of preventive strategy it will be a major challenge of public health in future. Conclusion: This study provided information on the prevalence and antimicrobial susceptibility patterns of Shigella isolates in Ardabil province, Iran. Also this study showed a high-level of resistance to commonly used antibiotics among Shigella isolates.

Background & objective: Pneumocystis pneumonia (PCP) is responsible for pulmonary infection in immunocompromised patients. This study aimed to investigating the frequency of Pneumocystis colonization in patients hospitalized in the intensive care unit (ICU) and evaluating the relationship between PCP and Pneumocystis coloniza­tion. Methods: In the current cross sectional study bronchoalveolar lavage (BAL)fluids of 100 patients were collected from surgery and neurosurgery ICUs with different underlying corticosteroid therapy conditions. Patients were divided into 2 groups (patients who received corticosteroids and not received corticosteroids). Direct examination on BAL fluids was performed by the Gomori methenamine silver andGiemsa staining techniques. Additionally, 2 filtered air samples of the 2 above mentioned units were collected. A nested-PCR targeted mtLSUrRNA gene and sequencing were used to identify Pneumocystis spp. Results: In direct microscopy, 31 out of 100 hospitalized patients (31%) showed positive results. Twenty-three (46%) of smear positive patients were from the group of patients who received corticosteroid, the other 8(16%) were from the group of patients who didn’t receive corticosteroids (P= 0.001). Pneumocystis jirovecii DNA was detected in 77 out of 100 BAL samples by nested-PCR (77%) in which 40(52%) and 37(48%) samples were obtained from the patients who received and not received corticosteroids, respectively. Pneumocystis genome was found in 1 of the 2 filtered air samples. Conclusion: A significant number of patients who received corticosteroids were also colonized by P. jirovecii that may predispose to PCP or be transmitted to susceptible patients. A significant relationship was observed between the mean hospital stay and detection rate.

Breast carcinoma is a common cause of cancer death in women worldwide. CD44± cells were isolated from MCF7 cell line by magnetic-activated cell sorting (MACS) and treated with methylsulfonylmethane (MSM), allicin, and the combination of them. The cytotoxicity and cell cycle arrest were measured using MTT assay and flow cytometry. Moreover, mRNA levels of apoptosis regulators Bax, p53, and caspase-3 were measured using reverse transcriptase-polymerase chain reaction (RT-PCR). The combination treatment inhibited CD44− and CD44+ cells in the G2/M and S phases of the cell cycle, respectively. Importantly, Bax expression was significantly higher in the MSM/allicin-treated CD44+ cells than in the MSM- or allicin-treated cells (P

Historically, tuberculosis has been the leading cause of death throughout human history. Tuberculosis infection (TB) causes by Mycobacterium tuberculosis that is very dangerous and can affect any parts of the body, especially lungs. Tuberculosis infection still remains a serious threat to human public health due to its contagious nature, capability to stay latent form in host for indefinite time and then appear as active disease. It is estimated that one third of world’s population, nearly 2 billion persons are infected with Mycobacterium tuberculosis. Transmission occurs among people through inhalation of infected droplets. Lungs and especially alveolar macrophage are primary sites of infection. Mycobacterium tuberculosis bacilli by preventing fusion of phagosome with lysosome can remain alive inside the macrophages. Such situation defined as latent infection. In fact, persons with latent tuberculosis infection (LTBI) are only infected with M. tuberculosis without any sign of infectious. Latent infection in compared with active infection is not contagious, but in about 10-5 percent of people will develop active tuberculosis especially in elderly and people who use immunosuppressive drugs. Pulmonary TB is an active form of tuberculosis infection in which bacteria can spread among people by infected droplets. So identifying and treating people with latent TB infection can significantly reduce the progression of latent form to active infection. The tuberculin skin test (TST) is the most widely used test in worldwide that is applied to determine a person who is infected with M. tuberculosis. TST provide valubale information for diagnosis LTBI however its specificity can be reduced by bacillus Calmette-Guérin (BCG) vaccination and infected with non-tuberculous mycobacteria (NTM). In TST test host hypersensitivity responses to Purified protein derivative (PPD) from mycobacterium are evaluated. TST positive reaction indicates the presence of high risk for acquiring TB infection or progression of latent tuberculosis to active form. Previous studies indicated that there is correlation between TST response and subsequent risk of active TB. Experimental evidence has shown that treatment of latent infection in the basis of positive TST reduces the risk of active TB. Although TST is far from gold standard but it's low cost and simplicity make it a suitable laboratory test especially in developing country.

Objective(s): Tuberculosis (TB) has still remained a global health issue. One third of the world's population is infected with tuberculosis and the current BCG vaccine has low efficiency; hence, it is necessary to develop a new vaccine against TB. The aim of the current study was to evaluate the efficiency of a novel DNA vaccine encoding Mtb32C-HBHA antigen in inducing specific immune responses against Mycobacterium tuberculosis. Materials and Methods: A DNA plasmid vaccine expressing Mtb32C-HBHA fusion protein was constructed and its ability in protein expression was examined by RT-PCR and Western blot methods. Female BALB/c mice were vaccinated with 100 μg of purified recombinant vector in an attempt to assess its immunogenicity and protective efficacy. Further, the cytokines, IFN-γ, IL-12, IL-4, IL-10, and TGF-β were assessed. Results: The levels of all the studied cytokines were significantly increased (P

Abstract Background Nano-scale dendrimers are synthetic macromolecules that frequently used in medical and health field. Traditional anibiotics are induce bacterial resistence so there is an urgent need for novel antibacterial drug invention. In the present study seventh generation poly (amidoamine) (PAMAM-G7) dendrimer was synthesized and its antibacterial activities were evaluated against representative Gram- negative and Gram-positive bacteria. Methods PAMAM-G7 was synthesized with divergent growth method. The structural and surface of PAMAM-G7 were investigated by transmission electron microscopy, scanning electron microscope and fourier transform infrared. Pseudomonas. aeruginosa (n = 15), E. coli (n = 15), Acinetobacter baumanni (n = 15), Shigella dysenteriae (n = 15), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Staphylococcus aureus (n = 15) and Bacillus subtilis (n = 10) have been used for antibacterial activity assay. Additionally, representative standard strains for each bacterium were included. Minimum Inhibitory Concentration (MIC) was determined using microdilution method. Subsequently, Minimum Bactericidal Concentration (MBC) was determined by sub-culturing each of the no growth wells onto Mueller Hinton agar medium. The cytotoxicity of PAMAM-G7 dendrimer were evaluated in HCT116 and NIH 3 T3 cells by MTT assay. Results The average size of each particle was approximately 20 nm. PAMAM-G7 was potentially to inhibit both Gram positive and gram negative growth. The MIC50 and MIC90 values were determined to be 2–4 μg/ml and 4–8 μg/ml, respectively. The MBC50 and MBC90 values were found to be 64–256 μg/ml and 128–256 μg/ml, respectively. The cytotoxity effect of dendrimer on HCT116 and NIH 3 T3 cells is dependent upon exposure time to and concentration of dendrimers. The most reduction (44.63 and 43%) in cell viability for HCT116 and NIH 3 T3 cells was observed at the highest concentration, 0.85 μM after 72 h treatmentm, respectively. Conclusions This study we conclude that PAMAM-G7 dendrimer could be a potential candidate as a novel antibacterial agent.

Minimum Inhibitory Concentration (MIC) of allicin were determined for 11 bacterial strains using 6 culture media including Todd Hewitt Broth (THB), Brain Heart Infusion (BHI) Broth, Tryptic Soy Broth (TSB), Mueller Hinton Broth (MHB), Luria Bertani (LB) Broth, and Brucella Broth (BB) at 37 °C. The chemical stability of allicin as a function of media was measured by HPLC. The MICs for most individual isolates grown at the same temperature varied with the media used. Higher MICs were obtained in BB, THB, BHI, TSB/MHB and LB with geometric mean values of 272.7, 145.2, 90.5, 77.3/72.6 and 46.7 μg ml−1 respectively. In media with higher MICs a big percent of allicin disappeared within the first 4 h of incubation and apparently allicin had shorter half-life compared to those with lower MIC values. The results showed that temperature directly influences the stability of allicin and shorter half-life was found at 37 °C.We conclude that the type of culture media, markedly influences the chemical stability of allicin and accordingly its MIC in a given bacterial species.

Background and Objectives: After live attenuated and subunit vaccines, DNA vaccines were introduced as a third generation vaccine in the field of vaccinology. This type of vaccine is a promising approach to deal with infectious agents in the future. Although, many aspects of this type of vaccine has not yet been identified, its use has been initiated in humans and clinical trials, and several DNA vaccines have been developed against veterinary infectious diseases. This generation of vaccine has provided new approaches to deal with and control existing diseases. In addition to infectious diseases, this type of vaccine can also be used against different types of tumors. Despite numerous attempts, only one type of DNA vaccine has been approved for use in human. The present study focuses on biology, advantages, and disadvantages of DNA vaccine and investigates its capacity in stimulating different types of immune responses.

Background & objectives: Candidiasis is a fungal infection which is caused by Candida spp. Candida albicans is the most common agent of candidiasis. This infection may cause various side effects during pregnancy including prematurity, chorioamnionitis, candidal pneumonia, and systemic candidiasis of infants. This research was conducted for determining the prevalence and antibiotic resistance pattern of Candida spp, collected from pregnant women admitted to health centers in Ardabil, Iran. Methods: Totally, 408 subjects were included in this study. Demographic data and risk factors were recorded using a questionnaire. Two swab samples were taken from vulvovaginal mucus. One swab was used for preparing smear and direct microscopic examination and the second one used for cultivating the specimen. After identification of Candida spp., antimicrobial resistance pattern was determined by disk diffusion method against Fluconazole, Ketoconazole, Clotrimazole, Nystatin and Amphotericin B. Results were interpreted according to CLSI guidelines. The data were analyzed by χ2 and t-test using SPSS-19. Results: Out of 408 subjects, 143 cases (35%) were positive for candida spp. The Candida albicans with 119 (83.2%) cases was the most prevalent species followed by Candida glabrata, Candida krusei, Candida parpsilosis and Candida tropicalis.According to disk diffusion test, overall 116 (81.1%) isolates were resistant to Fluconazole, 100 (69.9%) to Ketoconazole, 67 (46.9%) to Clotrimazole and 25 (17.5%) to Amphotericin B. Candida spp. had a highest sensitivity (118, 82.5%) to Nystatin. For Candida albicans 97(81.5%) isolates were resistant to Fluconazole and 99(83.2%) isolates to Nystatin. For Candida glabrata 10 (90.9%) isolates were resistant to Fluconazole, and 9(81.8%) sensitive to Nystatin. Conclusion: According to the results of this study, vulvovaginal candidiasis is prevalent among pregnant women in Ardabil and isolates were significantly resistant against commonly used antifungal drugs. Nystatin was the most effective against Candida spp. As antibiogram for fungal agents is not routinely performed, the similar periodical studies could be useful for choosing appropriate antibiotics in treatment of vulvovaginal candidiasis.

Background: Despite advances in the vaccinology and chemotherapy in the past century, tuberculosis is still responsible for two million deaths every year. Emergence of multi-drug resistant strain and coinfection of TB-HIV make it a serious concern. Treatment and control of tuberculosis is a great health burden in every community. Active tuberculosis in children has very severe consequences especially those who are under 5-years-old, therefore vaccine indication should be taken. Bacille Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis that has been used for providing immunity or protection against tuberculosis (TB). In addition, BCG provides relative protection against leprosy and Buruli ulcer, it also can be used for treatment of bladder cancer. BCG is the most widely administered vaccine around the world. It has been given to over three billion individuals over the past decades. At first it was developed in 1908 at the Pasteur Institute in Lille by Albert Calmette and Camille Guérin. In fact BCG is a strain of Mycobacterium bovis that bear deletion in its genome following too long subculture in special media. Deletion in region of deletion 1 (RD1), a specific region of Mycobacterium bovis genome, has decreased pathogenicity of BCG strain. Following culture of BCG on different media since 1921 make genetic variation in the BCG strains that have specific characteristics. BCG should begin given to only immune-competent individuals and should not be administered to immunocompromised people. This vaccine is not effective in people formerly infected or sensitized with environmental mycobacteria. Previous meta-analysis studies indicate that BCG has variable range of protection from 0 to 80 percent against pulmonary TB, but is very effective against severe disseminated forms such as meningitis and miliary form of TB. Despite many research and develop new generation vaccine against TB, BCG vaccine still remains as the only effective vaccine because many efforts to replace it with better ones were unsuccessful.

Background: Tuberculosis is a life threatening disease that is partially prevented by BCG vaccine. Development of more effective vaccines is an urgent priority in TB control. Ag85a and Tb10.4 are the members of culture filter protein (CFP) of M. tuberculosis that have high immunogenicity. Objective: To analyze the immunogenicity of Ag85a-Tb10.4 DNA vaccine by enzyme-linked immunosorbent assay (ELISA). Methods: In this study a previously described plasmid DNA vaccine encoding Ag85a-Tb10.4 was used to examine its capability in the stimulation of immune responses in an animal model. Female BALB/c mice were vaccinated with 100 μg of purified recombinant vector intramuscularly 3 times at two-week intervals and the levels of five cytokines including IFN-γ, IL-12, IL-4, IL-10 and TGF-β were measured. Results: The levels of IFN-γ and IL-12 for the mice following immunization with Ag85A-Tb10.4 was significantly greater than that of the BCG and control group (p

Background & objectives: Streptococcus pneumoniae is one of the major causes of vaccine - preventable diseases worldwide. Current pneumococcal vaccines consist of serotype specific capsular polysaccharide antigen and do not offer full clinical protection against pneumococcal diseases. Due to such limitations, a new generation of protein-based pneumococcal vaccines is being developed. The objective of this study was to determine the distribution of gens encoding five protein antigens including pneumococcal histidine triad D and E (phtD, phtE), rlr- regulated gene A (rrgA), Autolysin (lytA) and Pneumococcal surface protein C (pcpC) among pneumococcal isolates collected from nasopharyngeal specimens in healthy children. Methods: A total of 43 pneumococcal isolates were collected from nasopharyngeal specimens of healthy children attending the kindergartens in Ardabil province. The strains were identified using optochin susceptibility and bile solubility testes and further confirmed by amplification of capsular polysaccharide A gene (cpsA). PCR was used for screening the presence of pcpC, phtD, phtE, rrgA and lytA genes. Results: 81.4 % of isolates were found to contain at least one of the tested genes. lytA, pcpC, phtE, phtD and rrgA were detected in 70, 60, 39.5, 35 and 25.5 percent of isolates, respectively. The results showed that the genes were not distributed consistently among the isolates and for obtaining a full coverage pneumococcal vaccine, multiple choices of these antigens should be included.

Background and Objectives: Group B streptococci (GBS) are the major cause of neonatal and maternal infections. They are susceptible to penicillin, ampicillin and first-generation cephalosporins. However, resistance to other antibiotics such as erythromycin and clindamycin is common among GBS strains. The aim of this study was to evaluate the antimicrobial activity of allicin against colonizing GBS strains in vitro. Methods: Garlic extract was prepared and allicin was purified using semi-preparative HPLC procedure. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of allicin were determined for 52 GBS strains using microdilution method in Todd Hewitt broth medium. Results: MIC of allicin was 64-128 µg/mL (MIC90 = 128) and MBC of allicin was 128 to 512µg/mL (MBC90 = 256) for GBS strains. Conclusion: The results of this study showed that allicin can inhibit growth of GBS in vitro. Further studies on allicin might be worthy of evaluation as a therapeutic agent in treatment of GBS infections.

Background and Objective: Reports on MRSA strains are increasing worldwide. The aim of this study was to find the prevalence of MRSA strains isolated from clinical specimens and to evaluate their resistance profile. Additionally we compared the phenotypic and genotypic methods for detection of methicillin resistance. Materials and Methods: In this cross-sectional study, a total of 41 isolates of S. aureus were collected from clinical specimens at two teaching hospitals in Ardabil, Iran. All isolates were identified at the species level by standard biochemical tests. The methicillin resistance were evaluated using three methods: PCR for mecA gene, agar dilution for determination of oxacillin MIC and disk diffusion test to detect methicillin, oxacillin and cefoxitin resistance. Antimicrobial resistance patterns were determined by disk diffusion method. Results: The results identified 19 (46.3 %) out of 41 isolates as MRSA. Most of the MRSA strains (68.4%) were isolated from patients hospitalized in ICU. All isolates were susceptible to vancomycin, mupirocin and linezolid. Among other antibiotics co-trimoxazole was more active against MRSA isolates. Using PCR as reference method all the phenotypic tests showed 100% specificity. The sensitivity for MIC test and cefoxitin was 100% and for methicillin and oxacillin disks was 77.7% and 89.5%, respectively. Conclusion: The prevalence of MRSA strains in our hospitals especially in ICU ward was high and disk diffusion testing using cefoxitin or oxacillin MIC test as an alternative to PCR for detection of MRSA is recommended.