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Noormohamad Mansoori,1 Farzam Vaziri,2,3 Sirus Amini,4 Sharareh Khanipour,2,3 Shahin Pourazar Dizaji,2,3 Masoumeh Douraghi1,5 1Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; 2Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; 3Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran; 4Regional Tuberculosis Reference Laboratory, Tehran University of Medical Sciences, Tehran, Iran; 5Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, IranCorrespondence: Masoumeh DouraghiDivision of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, PO Box: 14155-6446, Tehran, IranTel +98 21 42933152Fax +98 21 88954913Email mdouraghi@tums.ac.irIntroduction: Despite the moderate incidence of tuberculosis (TB) in many parts of Iran, Golestan province had a permanently higher TB incidence rate than the national average. Moreover, Golestan province receives immigrants, mainly from TB-endemic areas of Iran and neighbor countries. Here, we aimed to characterize the circulating Mycobacterium tuberculosis complex (MTBC) isolates in terms of the spoligotype and drug resistance patterns, across Golestan province.Materials and Methods: A set of 166 MTBC isolates was collected during July 2014 to July 2015 and subjected to drug susceptibility testing for first- and second-line anti-TB drugs and spoligotyping.Results: Of 166 MTBC isolates, 139 (83.7%) isolates were assigned to 28 spoligotype international types (SITs). The most frequent SITs were SIT127/Ural-2 (n=25, 15.1%), followed by SIT1/Beijing (n=21, 12.7%) and SIT3427/Ural-2 (n=18, 10.8%). The set of 18 isolates (10.8%) showed resistance to at least one drug, which mainly belonged to SIT1/Beijing (n=7, 38.9%), orphan patterns (n=4, 22.2%) and SIT357/CAS1-Delhi (n=3, 16.7%). In addition, four isolates (2.4%) were resistant to pyrazinamide. The analysis of mutation corresponded to resistance to rifampin and isoniazid showed that two isolates had Ser531Leu substitution in rpoB, four isolates had Ser315Thr substitution in katG and one isolate had [C(− 15)T] in inhA locus.Conclusion: High diversity in spoligotypes of the MTBC isolates and lack of dominant genotype might be due to residence of immigrants in this region and consequent reactivation of latent infection. In addition, due to the presence of extensively drug-resistant (XDR) isolates in Golestan province, it is important to conduct future studies to determine transmission pattern of drug-resistant isolates in this region.Keywords: Mycobacterium tuberculosis, tuberculosis, spoligotyping, genotyping, transmission

Stenotrophomonas maltophilia isolates are responsible for various hospitalacquired infections and are particularly increasing in the immunocompromised patients. The aim of this study was to determine the clonal relatedness between S. maltophilia isolates originating from the clinic and environment. A total of 150 S. maltophilia isolates from patients and 1108 environmental samples obtained in three hospitals from Tehran. Following molecular identification targeting 23S rRNA gene, the clonal relatedness of the environmental and clinical isolates was determined using pulsed field gel electrophoresis (PFGE). Of the 150 clinical and 18 environmental isolates identified using phenotypic tests, the speciation of 120 and 15 was confirmed by targeting the 23S rRNA gene. The 24 common pulsotypes (PTs) and 32 single PTs were identified by PFGE. Only a small cluster was shared among the clinic and environment within a hospital; therefore, the intra-hospital dissemination of certain isolates of S. maltophilia among the clinic and environment was demonstrated. [ABSTRACT FROM AUTHOR]

Aims: Little is known about the resistance rate and susceptibility profile of Clostridium difficile isolates in Iran. Therefore, the aim of present study is to assess the rate of drug‐resistant C. difficile. Methods and Results: During a 6‐year period, four hospitals submitted 735 stool specimens from patients suspected for C. difficile infections to the anaerobic bacteriology laboratory. The 46 C. difficile isolates were subjected to disc diffusion and minimum inhibitory concentration (MIC) Test Strips. All isolates were susceptible to vancomycin (VAN) while the highly resistant phenotypes of metronidazole (MTZ) (67·4%), moxifloxacin (78·3%), ciprofloxacin (69·5%) and tetracycline (82·6%) were observed. Of more concern, 67·3% of C. difficile isolates displayed multidrug‐resistant phenotypes. More than half of the isolates (n = 27, 58·6%) were coresistant to ciprofloxacin and moxifloxacin. The MIC90 of VAN was ≤2 mg l−1, whereas this value for MTZ, ciprofloxacin, moxifloxacin and tetracycline was higher than the resistance breakpoints. According to the comparison of interpretive categories for two tests, the categorical agreement was less than 90% for VAN, ciprofloxacin and tetracycline. Conclusions: The disc diffusion method can be used to detect the isolates with reduced susceptibility to MTZ or moxifloxacin. The high rate of resistance to fluoroquinolones highlights the possibility of the emergence of hypervirulent strains in our settings. Significance and Impact of the Study: This study provides data regarding the high level of resistance against multiple antibiotics except VAN. [ABSTRACT FROM AUTHOR]

Background: Bacillus cereus is one of the important agents of the food-borne diseases worldwide. In the present study, the dried vegetable samples distributed in Tehran, Iran were evaluated in order to isolation, identification and enumeration of B. cereus. Methods: A total of 140 samples containing open and packed dried vegetables were randomly purchased from different areas of Tehran, Iran from March to August 2015. Dried vegetable samples were equally divided into seven groups, including dill, parsley, coriander, tarragon, mint, his, and pot roast. After culturing of samples, isolated B. cereus colonies were enumerated and identified using biochemical tests. The statistical tests were done by SPSS 16 (Chicago, IL, USA) software. Results: Totally, 44 out of 140 (31.4%) dried vegetable samples were contaminated with B. cereus. The B. cereus contamination were found in 25 out of 70 (35.7%) and 19 out of 70 (27.1%) open and packed dried vegetable samples, respectively. There was no statistically significant difference (p>0.05) between contamination rate of B. cereus in open and packed dried vegetable samples. Also, contamination rate of B. cereus was not significantly different (p>0.05) among various kinds of vegetable samples. Conclusion: Our study showed that dried vegetables sampled from Tehran, capital of Iran were contaminated with B. cereus. More researches are required in order to evaluate the prevalence of B. cereus contamination in raw and fresh vegetable samples consumed in the country. [ABSTRACT FROM AUTHOR]

The Acinetobacter baumannii virulence protein Bap is encoded by a large gene and contains both variable sequence and repetitive modules. To date, four primer sets targeting different regions of bap have been designed, but no study has evaluated all these primers simultaneously for detection of bap. Here, we assessed the effect of primer sets Bap I-IV, on detection of bap both in silico and in vitro. Using the primer set Bap II, all 143 tested strains yielded an amplicon corresponding to the bap gene. This primer set showed the highest sensitivity (100, 95% CI: 97·9-100%) compared to the other primer sets. This study demonstrates that primer set Bap II performs with optimal efficiency for detection of the bap gene among different strains. Significance and Impact of the Study This study investigated the effect of nucleotide variation on PCR detection of the bap gene in various Acinetobacter baumannii strains. Since bap is the target gene for many detection assays, this variation can affect the detection efficiency. Here we present a primer set Bap II with optimal detection efficiency amongst 143 different strains, as shown by in silico and in vitro evidence. [ABSTRACT FROM AUTHOR]

Comprehensive data on drug-resistant patterns of Acinetobacter baumannii isolates in developing countries is limited. We conducted a multihospital study to assess the rate and trend of drug-resistant phenotypes in Ac. baumannii using standardized definitions and to determine the remaining therapeutic options against resistant phenotypes. The 401 nonduplicate isolates were collected from six hospitals which are geographically distributed across Tehran, Iran over a 3-year period. Following PCR of bla OXA-51-like gene, susceptibility testing was performed against nine antimicrobial agent categories. Three hundred and ninety (97%) isolates were resistant to least two carbapenems; carbapenem-resistant Ac. baumannii. The majority of isolates (366, 91·3%) were extensively drug resistant ( XDR) and the rest of the isolates were classified as multidrug resistant (26, 6·8%) and susceptible (9, 2·2%). The rate of XDR- AB slightly decreased from 93·8% in 2011 to 89·8% in 2013. A considerable decrease in resistance to doxycycline, minocycline and tigecycline was demonstrated. The XDR- AB isolates showed susceptibility to gentamicin (10·4%), tobramycin (23%), ampicilin-sulbactam (30·1%), minocycline (32·8%), tigecycline (10·7%), doxycycline (21·6%), colistin (100%) and polymixin B (100%). We demonstrated the rising trend of resistance to all antibiotic categories except tetracyclines and folate pathway inhibitors. We found that the treatment options against XDR- AB are extremely limited and each treatment alternative including even old, but safe, antibiotics might be considered. Significance and Impact of the Study The high frequency of drug-resistant phenotypes including carbapenem-resistant Acinetobacter baumannii, multidrug-resistant, and extensively resistant has been demonstrated in Ac. baumannii isolates tested here. As the antibiotic resistance pattern of isolates varies in different geographical regions, this study can provide comprehensive information about the antibiotic resistance profile of Ac. baumannii isolates in Tehran. In addition, the resistance profiles could be effectively considered by clinicians to manage antibiotic therapy. This work also emphasizes on the prudent use of antibiotics and the monitoring of antibiotic susceptibility trend and rate. [ABSTRACT FROM AUTHOR]

Background and Objective: Stenotrphomonas maltophilia is an opportunistic nosocomial pathogen with high mortality in immunocompromised cases. The aim of this study was to isolate and identify Stenotrphomonas maltophilia in the hospitals' environment and wards. Material and Methods: In this cross-sectional study, a total of 1108 samples were collected from environment of two hospitals during 12 months. Identification of isolates was performed using biochemical, phenotypic (intrinsic resistance to carbapenems) and molecular methods (amplification of 23S rRNA gene). Results: Of the studied samples, 186 (16.78%) nonfermentative gram negative bacilli (NFGNB) were identified. Amongst NFGNB, 18 (1.62%) isolates were identified as S. maltophilia by using biochemical tests. Of 18 biochemically identified isolates, 15 (83.3%) were confirmed via PCR. Sinks (40%) and men surgery ward ( 33.3 %( were the most contaminated sites and wards of hospitals, respectively. Conclusion: S. maltophilia is repeatedly isolated from sink which shows that the moist hospital environments need to be considered as a source for dissemination of bacteria. [ABSTRACT FROM AUTHOR]

Background and Objectives: Of the genes conferring resistance to carbapenems in Acinetobacter baumannii, the bla OXA-23 gene is the most widely found across the world. The gene carrying bla OXA-23 transposons in A. baumannii isolates of global clones GC1 and GC2 is found worldwide. Here, we examined whether transposons play a role in the dissemination of the bla OXA-23 in globally distributed clones, GC1 and GC2 A. baumannii isolates from Iraq., Materials and Methods: The 119 non-repetitive A. baumannii isolates including 94 recovered from clinical specimens and 25 isolates from hospital environment between September 2021 and April 2022 from different medical centers located at various regions in Baghdad, Iraq. The global clones (GC) and the genes encoding carbapenem resistance, including bla OXA-23 , bla OXA-24 , and bla OXA-58 were identified using multiplex PCR assays. Antibiotic susceptibility testing was performed by the Kirby-Bauer disk diffusion susceptibility method. The transposons carrying bla OXA-23 were examined using PCR mapping. In cases when carbapenem susceptible A. baumannii isolates were found, they were subjected to E test, full length sequencing of bla OXA-Ab (bla OXA-51-like ) and Institut Pasteur multi-locus sequence typing scheme., Results: All but two isolates (92 clinical and 25 environmental) were identified carbapenem-resistant A. baumannii (CRAB). Of 117 CRAB isolates, 20 belong to GC1, 19 contained bla OXA-23 ; of them, 17 isolates harbored the bla OXA-23 located on Tn2006. Among the 46 CRAB belonging to GC2, 39 contained bla OXA-23 ; of them, 34 carried the bla OXA-23 located on Tn2006. The remaining GC1 and GC2 isolates, one GC1 as well as one GC2 isolate, were susceptible to imipenem, doripenem, and meropenem and considered carbapenem-susceptible A. baumannii (CSAB). Full-length sequencing of the bla OXA-Ab and MLST for the two CSAB isolates belonging to GC1 and GC2 confirmed that the GC1 isolate belongs to ST 623 and contained an allele that encodes an bla OXA-69 variant of the bla OXA-Ab while the GC2 belong to ST2 and carried an bla OXA-66 variant., Conclusion: This study provides evidence for the dissemination of bla OXA-23 on the Tn2006 in CRAB isolates in Baghdad, Iraq. It appears that this transposon is widespread in GC1 and 2 isolates as in the other parts of the world. Interestingly, one GC1 and one GC2 isolate from Iraq were found to be susceptible to carbapenem while the isolates belonging to GC1 and GC2 have so far rarely been found to be susceptible to carbapenem globally., (© 2024. The Author(s).)

Filamentous hemagglutinin (FHA) is a critical adhesion molecule produced by Bordetella pertussis (BP), the causative agent of highly contagious respiratory infection known as whooping cough. FHA plays a pivotal role in the pathogenesis of whooping cough and is a key component of acellular pertussis vaccines (aPV). However, conventional purification methods for FHA often involve labor-intensive processes and result in low purity and recovery rates. Therefore, this study explores the use of monoclonal and polyclonal antibodies as specific tools to achieve highly pure and efficient FHA purification. To generate FHA-specific antibodies, polyclonal antibodies were produced by immunizing sheep and monoclonal antibodies (MAbs) were generated by immunizing mice with recombinant and native FHA. The MAbs were selected based on affinity, isotypes, and specificity, which were assessed through ELISA and Western blot assays. Two immunoaffinity columns, one monoclonal and one polyclonal, were prepared for FHA antigen purification. The purity and recovery rates of these purifications were determined using ELISA, SDS-PAGE, and immunoblotting. Furthermore, the MAbs were employed to develop an ELISA assay for FHA antigen concentration determination. The study's findings revealed that immunoaffinity column-based purification of FHA resulted in a highly pure antigen with recovery rates of approximately 57% ± 6.5% and 59% ± 7.9% for monoclonal and polyclonal columns, respectively. Additionally, the developed ELISA exhibited appropriate reactivity for determining FHA antigen concentration. This research demonstrates that affinity chromatography is a viable and advantageous method for purifying FHA, offering superior purity and recovery rates compared to traditional techniques. This approach provides a practical alternative for FHA purification in the context of aPV development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background & Objective: Cerebrospinal fluid (CSF) analysis is helpful in the diagnosis of infections of the central nervous system (CNS), especially after neurosurgical procedures. This study aimed to evaluate the diagnostic value of CSF markers for diagnosis of post-neurosurgical meningitis (PNM)., Methods: Patients with neurosurgical procedures whose CSF was obtained for any reason (meningitis and non-meningitis) during 2020 and 2022, at Imam Khomeini Hospital Complex, Tehran, Iran, were included. Serum and CSF lactate dehydrogenase (LDH), glucose, protein, white blood cells (WBC), red blood cells (RBC), and CSF/serum glucose and LDH ratio were compared between the patients who were diagnosed with PNM and those without meningitis., Results: A total of 115 patients were included, of whom 23 patients were diagnosed with PNM and 92 with non-meningitis. No significant differences were observed in patients' age, gender, and underlying diseases between the two groups. Findings showed a significantly ( P =0.029) lower level of the mean CSF glucose (59.5 mg/dL ±33.9) in patients with meningitis than in patients without meningitis (76.8 mg/dL ± 37.5). The mean CSF/serum glucose ratio was 43.7% in the meningitis group and 56.3% in the non-meningitis group ( P =0.008). The mean WBC count and neutrophil dominance were significantly higher in the meningitis group. No significant differences were observed in CSF LDH, Protein, and RBC between the two groups., Conclusion: A CSF glucose level of less than 60 mg/dL, a CSF/serum glucose ratio of less than 0.44, and a higher CSF WBC and neutrophil count can help diagnose PNM., Competing Interests: The authors report there are no competing interests to declare., (© 2024.)

Purpose: Prior studies have demonstrated that both dietary components and bariatric surgery modify the gut microbiota's composition. However, there is a scarcity of research that has examined the relationship between post-surgical dietary intake and changes in the gut microbiota. The aim of this study was to assess changes in gut microbiota following bariatric surgery and examine their association with postoperative dietary intake., Materials and Methods: The present study involved a sample of 42 adult women who were potential candidates for bariatric surgery, i.e., laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG). The assessment of dietary intake was conducted through the use of three-day food records, both at baseline and six months following the surgical procedure. The gut microbiota was determined through the detection of 16S ribosomal RNA (16S rRNA) gene sequencing., Results: After six months, a significant increase in abundance of Firmicutes (P = 0.01), Bifidobacterium (P = 0.01), and Ruminococcus (P = 0.04) in the LSG group was found. In contrast to the observed rise in Enterobacteria (P = 0.02) levels in the LRYGB group, no significant changes were detected in the composition of other gut microbiota over the 6-month monitoring period subsequent to LRYGB. The results of our study indicate that there is not a statistically significant relationship between dietary consumption and changes in the composition of the gut microbiota in individuals who have undergone LRYGB and LSG., Conclusion: Our findings suggest that there may not be a significant correlation between dietary intake following LRYGB and LSG, and the observed alterations in the gut microbiota during a six-month period of observation. Nevertheless, it is important to acknowledge that the sample size utilized in our study was limited, potentially leading to reduced statistical power and the possibility of yielding findings that do not accurately reflect reality., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Acinetobacter baumannii strains belonging to global clone 2 (GC2) contain resistance islands (AbGRIs), which are composed of genes conferring resistance to older and newer antibiotics. Here, to locate these genes in AbGRIs, the GC2 strains from Tehran, Iran were examined. Among the 170 A . baumannii , 90 isolates were identified as GC2. Of the genes that confer resistance to older antibiotics, tetA(B ), tetR(B) (tetracyclines), strA , and strB (aminoglycosides) were located in AbGRI1 of 65 GC2 isolates (72.2%). Of the other aminoglycosides, the aphA1b was located in AbGRI2-12b (63.6%), AbGRI2-12a (21.2%), or AbGRI2-1 (15.1%). The aacC1 and aadA1 genes were co-located within AbGRI2-1 (5.5%). The armA was located in AbGRI3-4 (77.7%) and AbGRI3 ABI221 (22.2%). Of sulfonamides, the sul1 was located within AbGRI2-1 (5.5%). Of beta-lactams, the bla TEM was located in AbGRI2-12b (42%), AbGRI2-12a (14%), AbGRI2-1 (10%), or AbGRI2 ABI257 (34%). The oxa23 gene conferring resistance to newer antibiotics (carbapenems) was located in AbaR4 (81.1%); of them, the AbaR4 was located within AbGRI1 in 45.2% of the isolates. This study showed that the GC2 isolates, which contained at least one AbGRI, disseminate in the hospital. Hence, it is likely that the AbGRIs play a significant role in conferring resistance to older and newer antibiotics in GC2 isolates from Iran. IMPORTANCE The majority of Acinetobacter baumannii isolates that are resistant to multiple antibiotics belong to one of the two major global clones, namely global clone 1 (GC1) and global clone 2 (GC2). The resistance islands, which contain variable assortments of transposons, integrons, and specific resistance genes, have been characterized in the genome of these GCs. In GC2 A. baumannii, the chromosomally located A. baumannii genomic resistance islands (AbGRIs) carry the genes conferring resistance to older and newer antibiotics. In this context, we tested whether GC2 isolates collected from a referral hospital carry the AbGRIs containing these genes. This study provided evidence for the circulation of the GC2 A. baumannii strains harboring AbGRI resistance islands between different wards of a referral hospital.

Aim: The Acinetobacter baumannii genomic resistance islands (AbGRIs), which were characterized in the genome of the global clone 2 (GC2) A. baumannii contain resistance genes. Here, we aimed to determine the occurrence of AbGRIs in GC2 A. baumannii obtained from COVID-19 patients in a referral hospital in Tehran, Iran., Methods: A total of 19 carbapenem-resistant A. baumannii (CRAB) isolates belonging to GC2 and sequence type 2 (ST2), including 17 from COVID-19 patients and two from the devices used in the ICU that the COVID-19 patients were admitted, were examined in this study. Antibiotic susceptibility testing was performed by the disk diffusion method. PCR and PCR mapping, followed by sequencing, were performed to characterize the structure of AbGRI resistance islands in the isolates tested., Results: The AbGRI3 was the most frequent resistance island (RI) detected, present in all the 19 isolates, followed by AbGRI1 (15 isolates; 78.9%) and AbGRI2 (three isolates; 15.8%). Notably, AbGRIs were identified in one of the A. baumannii strains, which was isolated from a medical device used in the ICU where COVID-19 patients were admitted. Furthermore, new structures of AbGRI1 and AbGRI3 resistance islands were found in this study, which was the first report of these structures., Conclusions: The present study provided evidence for the circulation of the GC2 A. baumannii strains harboring AbGRI resistance islands in a referral hospital in Tehran, Iran. It was found that resistance to several classes of antibiotics in the isolates collected from COVID-19 patients is associated with the resistance genes located within AbGRIs., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Pertussis, or whooping cough, is a highly contagious respiratory disease caused by Bordetella pertussis (BP). Pertactin (PRN) is one of the main immunogenic components of BP and is employed in many commercialized acellular pertussis vaccines (aPVs). Purification of this protein by conventional chromatography methods is challenging and commonly requires multiple laborious processes with low recovery. Using specific monoclonal antibodies (mAbs) for the purification of PRN antigen is expected to yield high purity and recovery of the target molecule., Methods: Recombinant PRN antigen was used to produce mouse mAbs using hybridoma technology. Structural and functional characteristics of the mAbs were assessed by ELISA, immunoblotting, and flow cytometry. Selected mAbs were employed to purify PRN by affinity chromatography, and the purity and recovery of the purified protein were analyzed by ELISA, SDS-PAGE, and immunoblotting. Moreover, ELISA and flow cytometry techniques were designed using these mAbs to detect PRN in different strains of BP., Results: Five mAbs were produced and selected based on their reactivity with native PRN. Our results demonstrate that purification of PRN by affinity chromatography resulted in a highly pure antigen with 75-85 percent recovery. In addition, ELISA and flow cytometry results indicated that these mAbs could recognize PRN in the bacterial cell walls of different BP strains., Conclusion: We successfully produced PRN-specific mAbs and designed an affinity chromatography method to purify PRN antigen with higher purity and recovery than conventional methods. These mAbs could be employed as valuable tools for the detection and purification of PRN for vaccine manufacturing., Competing Interests: Declaration of Competing Interest The authors reported no declarations of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Immigration is considered as a risk factor of tuberculosis (TB). Qom province receives millions of pilgrims and significant numbers of immigrants each year. Most of the immigrants to Qom, arrive from neighboring TB-endemic countries. This study aimed to identify the current circulating Mycobacterium tuberculosis genotypes in Qom province using 24-locus MIRU-VNTR genotyping., Methods: Eighty six M. tuberculosis isolates were collected during 2018-2022 from patients referring to Qom TB reference laboratory. The DNA of isolates was extracted and followed by 24 loci MIRU-VNTR genotyping which performed using the web tools available on MIRU-VNTRplus., Results: Of 86 isolates, 39 (45.3%) were of Delhi/CAS genotype, 24 (27.9%) of NEW-1, 6 (7%) of LAM, 6 (7%) of Beijing, 2 (2.3%) of UgandaII, 2 (2.3%) of EAI, 1 of S (1.2%) and 6 (7%) did not match with profiles present in MIRUVNTRplus database., Conclusions: About half of the isolates belong to Afghan immigrants; which warns health policy makers about the future situation of TB in Qom. Also, the similarity of Afghan and Iranian genotypes provides evidence that immigrants partake in the circulation of M. tuberculosis. This study underpin the studies about the circulating M. tuberculosis genotypes, their geographical distribution, the association of TB risk factors with these genotypes and the impact of immigration on the situation of TB in Qom province., (© 2023. The Author(s).)

Aminoglycosides are used to treat infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) strains. However, resistance to aminoglycosides has increased remarkably in the last few years. Here, we aimed to determine the mobile genetic elements (MGEs) associated with resistance to aminoglycosides in the global clone 2 (GC2) A. baumannii . Among the 315 A. baumannii isolates, 97 isolates were identified as GC2, and 52 of GC2 isolates (53.6%) were resistant to all the aminoglycosides tested. The AbGRI3s carrying armA were detected in 88 GC2 isolates (90.7%), and of them, 17 isolates (19.3%) carried a new variant of AbGRI3 (AbGRI3 ABI221 ). aphA6 was located in Tn aphA6 of 30 isolates out of 55 aphA6 -harboring isolates, and 20 isolates were found to harbor Tn aphA6 on a RepAci6 plasmid. Tn 6020 carrying aphA1b was detected in 51 isolates (52.5%), which was located within AbGRI2 resistance islands. The pRAY * carrying the aadB gene was detected in 43 isolates (44.3%), and no isolate was found to contain a class 1 integron harboring this gene. The GC2 A. baumannii isolates contained at least one MGE carrying the aminoglycoside resistance gene, located mostly either in the chromosome within AbGRIs or on the plasmids. Thus, it is likely that these MGEs play a role in the dissemination of aminoglycoside resistance genes in GC2 isolates from Iran., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Naderi, Talebi, Gheybizadeh, Seifi, Ghourchian, Rahbar, Abdollahi, Naseri, Eslami and Douraghi.)

Since the introduction of the Bacillus Calmette-Guérin (BCG) vaccine, the genomes of vaccine strains have undergone variations due to repeated passages in different laboratories and vaccine production facilities. Genetic variations have been considered as one of the effective factors in the BCG variable protective efficacy. Consecutive subcultures have been shown to play an essential role in causing genetic variations in several microorganisms, including Mycobacterium bovis BCG. Therefore, the world health organization (WHO) recommendation to limit the passages of master seed lot in the BCG vaccine production should be considered. Besides, the role of other external variables such as quality of the raw ingredients of the culture media, the type of the culture medium and the cultivation methods in the vaccine production has been poorly studied. Here, the effect of passages and culture medium on genetic variations in a BCG seed lot was investigated during a year. The findings of this study revealed a total of 19 variants compared to seed lot while the passages were more than the number recommended by WHO. The first culture of seed lot in the Sauton broth and Middlebrook 7H9 media, and the last subculture in Sauton broth had the least and the most variants, respectively. The observation of the higher number of variants in the last cultures on Sauton broth and Middlebrook 7H9 in comparison to the first and the middle cultures may indicate the effect of passages on the genetic variations in BCG. Additionally, more variants in BCG grown in the Sauton broth do not necessarily represent the greater ability of this medium to cause genetic mutations. For a better conclusion, it is required to examine the medium components as independent variables., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Asadian et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Immunotoxins are regarded as a type of targeted therapy for killing cells by highly potent bacterial, fungal or plant toxins. Shiga like toxins (SLTs) are a group of bacterial AB5 protein toxins that inhibit host cell protein synthesis through the removal of a single adenine residue from the 28S rRNA and lead to apoptosis. Here, we described the design and usage of a Stx-based immunotoxin that can induce the selective cytotoxicity and apoptosis in Fn-14-positive cells related to the colon and lung cancer. In the present study, the Stx2a-PE15-P4A8 fusion protein was expressed efficiently in E. coli (DE3) system when driven from inclusion bodies by 8 M urea. The Stx2a-PE15-P4A8 fusion protein was expressed efficiently in E. coli (DE3) system and then purified. The purified fusion protein could specifically target Fn-14 receptor existed on colon and lung cancer cell lines and suppress these cells in a dose-dependent manner. In addition, the protein was able to nearly 50 % of apoptotic cell death and maintains about 54 % of its stability after 24 h of incubation in mouse serum at 37 °C. Compared to PE38-P4A8 construct in our previous study, these results showed that the Stx2a-PE15-P4A8 construct can be an efficient therapeutic candidate for cancer immunotherapy., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Bacillus Calmette-Guérin (BCG) refers to a group of vaccine strains with unique genetic characteristics. BCG is the only available vaccine for preventing tuberculosis (TB). Genetic and biochemical variations among the BCG vaccine strains have been considered as one of the significant parameters affecting the variable protective efficacy of the vaccine against pulmonary tuberculosis. To track genetic variations, here two vaccine strains (Danish 1331 and Pasteur 1173P2) popularly used according to the BCG World Atlas were subjected to a comparative analysis against the Mycobacterium tuberculosis H37Rv, Mycobacterium bovis AF2122/97, and Mycobacterium tuberculosis variant bovis BCG str. Pasteur 1173P2 reference genomes. Besides, the presence or absence of the experimentally verified human T cell epitopes was examined., Results: Only two variants were identified in BCG Danish 1331 that have not been reported previously in any BCG strains with the complete submitted genome yet. Furthermore, we identified a DU1-like 14,577 bp region in BCG Danish 1331; The duplication which was previously seemed to be exclusive to the BCG Pasteur. We also found that 35% of the T cell epitopes are absent from both strains, and epitope sequences are more conserved than the rest of the genome., Conclusions: We provided a comprehensive catalog of single nucleotide polymorphisms (SNPs) and short insertions and deletions (indels) in BCG Danish 1331 and BCG Pasteur 1173P2. These findings may help determine the effect of genetic variations on the variable protective efficacy of BCG vaccine strains., (© 2022. The Author(s).)

Objectives: We aimed to identify the enterotoxigenic Bacteroides fragilis (ETBF) and bft subtypes among patients with diarrhea. In addition, we assessed whether DNA gyrase subunit B (gyrB) and neuraminidase (nanH) genes are useful determinants for identification of B. fragilis compared to 16S rRNA sequencing as a reference method., Methods: The 530 fecal specimens were cultured on BBE agar. The colonies which supposed to be a member of B. fragilis group were subjected to 16S rRNA gene sequencing and PCR assays targeting the Bacteroides fragilis group (BFG), gyrB and nanH. The B. fragilis toxin (bft) gene and its subtype was detected by PCR. The specificity of PCR assays was calculated considering the 16S rRNA gene sequencing as the reference method., Results: A total of 111 Gram-negative anaerobic coccobacilli were isolated from 530 fecal specimens using BBE agar. Of the 111 isolates, 100 (90.09%) were assumed to be a member of Bacteroides fragilis group as they yielded an amplicon through PCR using the group-specific primers (Bfra-F/g-Bfra-R). However, only 28 isolates out of 100 were definitively identified as species of Bacteroides using16S rRNA gene sequencing; of which 15 isolates were B. fragilis and the remaining 13 isolates were identified as B. thetaiotaomicron (n = 6), Parabacteroides distasonis (n = 3), B. vulgatus (Phocaeicola vulgatus) (n = 1), B. ovatus (n = 1), B. congonensis (n = 1) and B. nordii (n = 1). Among the 15 isolates of B. fragilis, 4 were found to be ETBF. Compared to the reference method, the specificity and accuracy of the PCR targeting gyrB gene (64.7% and 65%) was higher than of nanH (36.4% and 46%, respectively., Conclusions: This study demonstrated that more than one-fourth of B. fragilis isolates harbored bft gene and less than 1% of patients with diarrhea harbored ETBF. The slight agreement between the PCR assays -already used for identification of B. fragilis which targeting gyrB or nanH - and 16S rRNA gene sequencing as the reference method was noted., Competing Interests: Declaration of Competing interest The authors declare that they have no conflict of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)