دو ماهنامه میکروب شناسی پزشکی ایران
سال شانزدهم شماره 1 (بهمن و اسفند 1400)

 Pseudomonas aeruginosa is an opportunistic pathogen, and alginate is its most important factor in pathogenicity. The objective of the study is the immunogenicity evaluation of P. Pseudomonas aeruginosa alginate conjugated to exotoxin A as a vaccine candidate in mice.

 The mucoid strain of Pseudomonas aeruginosa 6494 was used to prepare alginate, and the separation of exotoxin A was done with the standard strain of PAO1. Alginate was extracted by means of sedimentation with cold ethanol, dialysis, enzymatic digestion and chromatography. To improve immunogenicity, purified antigen was coupled to exotoxin A with ADH as a spacer and EDAC as a linker. Based on confirmation tests, the resulting conjugate was devoid of specific toxicity and pyrogenic effect. Four groups of BALB/c female mice (each group was included 15 mice) were selected in the next step. The first group with the ALG, the second group with the D-ALG-ETA, and the third one with the ETA were vaccinated. The fourth group (control group) was vaccinated with normal saline. Vaccination was performed in three injectable doses with two-week intervals. Subsequently, serum samples were collected, and antibody responses were measured by the ELISA method for total IgG, IgG1, IgG2a, IgG2b, IgG3.

 After the second and third doses with ALG-ETA showed a significant increase in antibody titer against ALG-ETA in comparison with pure ALG. The titers of IgG2a, IgG2b, IgG, IgG1, IgG3 antibodies that produced against alginate increased in the third injection compared to the first conjugate injection, which was 2.9, 3, 5.2, 10, and 9.2, respectively.

 These results show that ALG from Pseudomonas aeruginosa increases anti-alginate antibodies in conjugate form with exotoxin A and can be considered an appropriate, effective adjuvant.

 Many local dairy products in Iran contain lactic acid bacteria. The aim of this study was to isolate and identify Lactobacillus brevis from the cottage cheese made in Bazoft city using biochemical and molecular methods and investigate its antimicrobial properties in vitro.

 In this study, ten local Bazoft city cheese samples were collected. After transferring to the Lab, serial dilution was obtained at 10-6 CFU/mL and cultured in MRS medium. Then bacilli and gram-positive bacteria were isolated and identified by biochemical methods. The identified Lactobacillus brevis genome was extracted and then amplified using polymerase chain reaction (PCR) to confirm the isolated strain. Finally, the PCR product was sent to Sinaclon for sequencing. The antimicrobial properties of Lactobacillus brevis supernatant were evaluated using the disk and well diffusion method against Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium , Pseudomonas aeruginosa, and Enterococcus faecalis. Antibiotic susceptibility was also assessed by the CLSI standard method.

 Six species of Lactobacillus were identified from cottage cheese samples. Selected Lactobacillus brevis showed good antimicrobial potency against five pathogenic bacteria. It showed the highest inhibitory effect against Salmonella Typhimurium during the well diffusion method with a mean diameter of growth inhibition zone of 19 mm and the least inhibitory effect against Enterococcus faecalis during the disc method with a growth inhibition zone diameter of 9 mm. It was also resistant to the antibiotics Vancomycin and Gentamicin, intermediate susceptible to Kanamycin and Nalidixic acid, and susceptible to Erythromycin, Tetracycline, Ampicillin, and Chloramphenicol.

 Isolated Lactobacillus brevis strain from the local Bazoft cheese has a good antimicrobial ability. By performing extra in vitro and in vivo tests, this native strain can be used more in medicines and the food industry.

 Sexually infections transmitted by bacteria are one of thetherapeutic and social problemsworldwide. The Real-time PCR assay is one of the most sensitive diagnostic and screening methods for these infections. The purpose of this study wassimultaneous detection of Chlamydia trachomatis and Mycoplasma genitaliumusing the TaqMan duplex real-time polymerase chain reaction.

 In the present study, we used extracted DNA from women with vaginal infections available in the bank ofthe molecular and medicalresearch center, Arak University of Medical Sciences, Arak, Iran. The duplex real-time PCR was evaluated to detectChlamydia trachomatis and Mycoplasmagenitalium in 110 vaginal andendocervical samples. To validate the diagnostic performance of the designedmethod, the tests were compared with a commercial diagnostic kit.

 The size of the ampliconsOmpA, 135 bp and MgPa, 145bp,indicated the accuracy of the primers designing procedures. The analysis of a panel of human STI revealed no cross-reactivity in the method. The diagnostic sensitivity and specificity of developedTaqMan duplex real-time PCR were 97% and 75%, respectively,compared to a commercial diagnostic kit.

 The results indicated that the used TaqMan duplex real-time PCR technique is specific and cost-effective and can be an excellent alternative to commercial kits for simultaneously detecting C. trachomatis and M. genitalium. Although the disadvantage of this method is its high cost, this disadvantage has significantly been resolved by the multiplex method.

 Urinary tract infection (UTI) is one of the most common infections in children. Arbitrary use of antibiotics has increased the resistant strains and transmits these resistant factors to other pathogens. Therefore, this study was designed to follow the resistance trend in 9-years in children with urinary tract infections referred to the Amirkola Children's hospital (Northern Iran).

 In this cross-sectional study, all children who had Urinary tract infections between 1994 to1998 and 2013 to 2018 with one month to 18 years old were included. Data (covering 9 years), such as age, sex, antibiotic resistance profile, urine culture results, and history of UTI, were collected retrospectively from patients' records. Cases were selected based on clinical and microbiological criteria. Antimicrobial susceptibility was determined by the Kirby–Bauer disk diffusion method.

 Escherichia coli was the most predominant organism isolated from urine samples. The highest drug resistance was related to cefazolin (83.3%). Resistance to nitrofurantoin was higher in children older than 5 years (P≤0.001). Moreover, the resistance pattern to gentamicin, amikacin, ceftriaxone, cephalexin, and imipenem differed in females and males (P>0.05).

 A 9-year study showed that 91.4% of the strains are still sensitive against amikacin which is a suitable treatment option in the studied strains. The establishment of antimicrobial stewardship programs and regular monitoring of antimicrobial resistance could help to reduce inappropriate prescribing for UTIs.

 Health Information Technology helps individuals prevent COVID-19. Many information technology applications have been developed to prevent Coronavirus infection globally; however, the quality level of these applications is uncertain. This study aims to evaluate the usability of the Mask mobile application, which is designed to fight COVID-19.

 The Mask mobile application is evaluated in two phases in this study. In the first phase, five experts performed the evaluation by Jacob Nielsen's 10 general principles, and in the second phase, 124 participants evaluated the Mask mobile application. Data collection tools were the System Usability Scale (SUS) questionnaire.

 Mask mobile application was poor in experts evaluating it in terms of error prevention, flexibility, and efficiency. In the user-based test method, the user score of this application was 89 out of 100, which was equal to an excellent ranking and grade A.

 The results have indicated that the usability of the Mask mobile application to prevent COVID-19 has been excellent. As a result of the study, mobile application developers might improve or modify their existing mobile health application designs to achieve optimal outcomes.

 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.

 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.

 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.

 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.

 The drug resistance mutations are key elements in the failure of long-term treatment of Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections. The mutation in the YMDD motif in the P gene of HBV is the most critical factor in antiviral drug (especially lamivudine) resistance. This study aimed to assess the YMDD motif and other polymerase gene mutations in individuals with HBV/HIV coinfection.

 All enrolled patients were under lamivudine treatment. Blood samples were collected from 37 HBV/HIV-positive patients, and DNA was extracted. The P gene was amplified by the PCR method with appropriate primers. The PCR products for detecting mutations in the P gene were sent to the Macrogen. To investigate the P gene mutations, the obtained sequences were compared with the polymerase gene of the HBV standard sequence in the GeneBank (accession number AB033559).

 The mean age of the patients was 34.1±5.7 years, of which 59.5% were male, and 40.5% were female. Of all patients, 56% were drug abusers, 35% had risky sexual behavior, 56% had prison history, and 33% had addicted wives. The 37 extracted samples were sequenced successfully. Among the studied samples (n =37), 28 patients had simultaneous mutations of YIDD and FLMAQ, 1 patient had YINN and FLIPH and 1 patient had YIDD and FSLAQ.

 In summary, drug-resistant variants were detectable in most coinfected patients with chronic Hepatitis B (CHB) and HIV. As a result of mutations, therapeutic strategies sometimes are not effective. Therefore, recognition and monitoring of drug resistance mutations are critical.

 Acinetobacter has been considered an important nosocomial pathogen since 1970. This study aims to investigate the prevalence of Acinetobacter infection during 2017-2021, study the antibiogram of these bacteria, and study the impact of gender on infection.

 This is a retrospective study in which data of the clinical samples received in Al-Kafeel Hospital, Kerbala, Iraq, between April 2017 and February 2021 were searched for Acinetobacter infection and their antibiotic susceptibility testing.

 The prevalence of Acinetobacter infection was 9.2% of cases. Male to Female ratio was 3:1, and there was a significant difference in Acinetobacter infection regarding gender. There were high resistance rates to major antibiotic classes. Maximum resistance was recorded for Amoxicillin (100%), followed by 3rd generation cephalosporins, including Cefotaxime (92.3%), Ceftriaxone (91.6%), Ceftazidime (91.3%), Cefixime (80%); in addition to growing resistance to carbapenems, Imipenem (42.8%) and Meropenem (62.2%). The lowest resistance rates were found to colistin sulfate (10%). There 80.7% of the isolates were multidrug-resistant MDR.

 Acinetobacter spp., is considered as fast emerging opportunistic agents with evolving drug resistance. Rationale use of antibiotics is important and necessary to prevent microbial resistance. Gender is considered a risk factor for Acinetobacter infection.