faramarz masjedian jazi

 The healthy people’s fecal flora in the community represents a large potential reservoir. Therefore, the current study aimed to detect antibiotic resistance patterns and virulence factors in Klebsiella pneumoniae isolated from healthy volunteers’ feces.

 Three hundred and fifty stool specimens were collected from sales rep healthy individuals referring to the Northwest Tehran Health Centers to get a health card. Bacterial isolation, identification, and antimicrobial susceptibility testing were conducted according to the routine instructions. In addition, polymerase chain reaction (PCR) was used to detect the genetic factors responsible for producing extended-spectrum β-lactamases (ESBLs: SHV, TEM, and CTX-M) blaKPC and other virulence genes.

 Among fecal samples analyzed, 60 (17.1%) K. pneumoniae were isolated. The results demonstrated that the highest resistance rate was related to piperacillin-tazobactam (n=25, 41.6%), followed by and meropenem (n=17, 28.8%) and co-trimoxazole (n=11, 18.3%), respectively. Also, all strains were susceptible to amikacin, gentamicin, and imipenem. The PCR results of the virulence gene showed that 95% (n=57) of isolates were positive for fimH gene, 93.33% (n=56) for BssS gene, 27 (45%) for rmpA gene. The PCR results for antibiotic resistance genes showed that 41.66% (n=25) had blaTEM gene, 38.33% (n=23) blaCTX-M gene, 35% (n=21) blaSHV gene and 3.33% (n=2) isolates had blaKPC gene, and none of these isolates carried magA gene.

 Antibiotic resistance was common among K. pneumoniae isolated from healthy volunteers’ feces who participated in this study. Transmission of resistant bacteria and plasmids through oral-fecal sources threats to the public, which could complicate treatment options for community-acquired infections caused by K. pneumoniae.

Human gastrointestinal tract harbors a variety of bacteria with vital roles in human health. Bacteroides fragilis is considered one of the dominant constituents of gut microflora which can act as an opportunistic pathogen leading to various diseases, including colon cancer, diarrhea, uterine and intrathecal abscesses, septicemia, and pelvic inflammation. In this study, multiple locus variable number of tandem repeats analysis (MLVA) was performed to genetically differentiate 50 B. fragilis isolates. Eight suitable tandem repeats (TRs) were selected by bioinformatics tools and were then subjected to PCR amplification using specific primers. Finally, MLVA profiles were clustered using BioNumerics 7.6 software package. All VNTR loci were detected in all isolates using the PCR method. Overall, B. fragilis isolates were differentiated into 27 distinct MLVA types. The highest diversity index was allocated to TR1, TR2, TR5, TR6, and TR8; with this taken into account, strain type 14 was the most prevalent with 12 strains belonging to this type. Clustering revealed three major clusters of A, B, and C. With regards to the pathogenicity of B. fragilis and the outcomes of infections related to this microorganism, it is imperative to study this microorganism isolated from both patients and healthy individuals. This study aimed at evaluating the efficiency of MLVA for the genetic differentiation of B. fragilis. The results of this study indicate the promising efficiency of MLVA typing for cluster detection of this bacterium.

Recurrent vulvovaginal candidiasis (RVVC) is one of the most common gynecological conditions in healthy and diabetic women, as well as antibiotic users. The present study was conducted to determine the relationship between TUP1 gene expression patterns and symptomatic recurrent C. albicans infections.

This research was performed on C. albicans samples isolated from the vaginal specimens obtained from 31 individuals with RVVC in 2016. The reference strain C. albicans ATCC 10231, 10 C. albicans strains isolated from minimally symptomatic patients, and 10 isolates from asymptomatic patients were also used as control strains. The relative mRNA expression of the TUP1 gene was quantified using quantitative real-time polymerase chain reaction (QRT-PCR).

The QRT-PCR results revealed that TUP1 mRNA expression was significantly decreased (0.001-0.930 fold) in the C. albicans isolates obtained from RVVC patients (P<0.001). However, no TUP1 expression was detectable in the isolates collected from asymptomatic patients. The results also indicated a significant correlation between TUP1 mRNA expression level and the severity of itching and discharge (P<0.001).

The present results were suggestive of the probable contribution of TUP1, as a part of the transcriptional repressor, to the severity of the symptoms related to C. albicans infections in the vagina. Regarding this, it is required to perform more in vivo studies using a larger sample size to characterize the regulatory or stimulatory function of TUP1 in the severity of RVVC symptoms. Furthermore, the study and identification of the genes involved in the severity of the symptomatic manifestations of C. albicans, especially in resistant strains, may lead to the recognition of an alternative antifungal target to enable the development of an effective agent.

Persister cells are defined as a subpopulation of bacteria that are capable of reducing their metabolism and switching to dormancy in stress conditions. Persister cells formation has been attributed to numerous mechanisms, including stringent response and Toxin-Antitoxin (TA) systems. This study aimed to investigate the hypothetical role of TA systems in persister cells formation of Brucella strains by evaluating toxins of type II TA systems (RelE, Fic, Brn T, cogT) expression.

Brucella strains treated with a lethal dose of gentamicin and ampicillin and to determine the number of surviving cells, bacterial colonies were counted at different time intervals. The role of TA systems in persister cell formation was then determined by toxin expression levels using qRT- PCR method.

Our results showed the viability of persister cells after 7 h. The results of relative qRT- PCR showed higher levels of toxin gene expression due to stress conditions, suggesting the possible role of TA systems in persister cells formation and antibiotics tolerance.

The results of this study showed that considering the importance of persistence and the tolerance to antibiotics, further studies on persister cells formation and related genes such as the TA system genes in Brucella strains might help us to identify the precise mechanisms leading to persister cells formation.

Listeriosis can be fatal for vulnerable groups of society. The disease has been widespread in recent years due to the large consumption of dairy and meat products. There is little information about the susceptibility of antibiotics and the pattern of Listeria monostigenesis gene resistance in Iranian society. Accordingly, the present study was conducted to investigate the antibiotic susceptibility and genetic resistance pattern of Listeria monosteogenesis strains isolated from different clinical and environmental sources.

In this study, 55 isolates were tested for antibiotic susceptibility by disk diffusion in agar and genetic pattern by polymerase chain reaction (PCR).

91% and 83% of the strains were resistant to streptomycin and Trimethoprim/sulfamethoxazole respectively. The result of PCR of antibiotic resistance genes showed that the prevalence of ermA, ermB, strA, tetA, tetS and ermC genes in isolates of Listeria monocytogenes was 50.90% (28/55), 21.81% (12/55), 89.9% (49/55), 0% (0/55), 21.81% (12/55) and 0% (0/55), respectively.

Due to the presence of 1/2a and 1/2c serotypes in isolated isolates and the presence of marker virulence genes in these strains, these isolates have potential for biological risks and listeriosis disease. Existence of this genetic pattern and resistance pattern can be partly due to the use of antibiotics during the production of dairy products. Regarding results of this study, the manner and rate of using animal antibiotics can be managed.

Klebsiella pneumoniae is an opportunistic microorganism causing nosocomial infection all over the world .This study aimed to investigate the prevalence of biofilm formation in K. pneumoniae isolated from patients and its correlation with the virulence factors. Biochemical tests were used for the identification of K. pneumonia isolated from patients referred to Motahari and Milad hospitals in Tehran, Iran, from October 2015 to June 2016. Kirby-bauer test was performed and biofilm formation was assessed phenotypically. Finally, virulence genes were detected by the PCR method. The highest resistance rate was against ceftazidime and cefotaxime (67%) and the least resistance rate was against imipenem and meropenem (39%). In addition, 81% of the isolates were biofilm producers according to the results of biofilm formation assay. Also, the results of PCR showed that all 57 biofilm producer isolates harbored fimA, mrkA, ecpA, and fimD virulence genes and 92% of these isolates harbored fimH virulence gene. Among non-biofilm producer isolates, 36% had fimA gene, 29% had ecpA gene, and none of these isolates carried mrkA and fimH genes. It seems that antibacterial resistance has a significant association with biofilm formation in K. pneumoniae isolates. Therefore, understanding resistance pattern and mechanisms leading to biofilm formation can facilitate efficient treatment of infections caused by this bacterium.

Salmonella and Shigella infections are important public health concerns among children. The emergence of antibiotic resistance amongst Salmonella and particularly Shigella isolates has posed serious problems in antimicrobial treatment worldwide. Data on local antibiotic resistance patterns are essential to design suitable antibiotic treatment guidelines.

The aim of the present study was to determine the prevalence and drug susceptibility patterns of Shigella and Salmonella species in addition to the detection of extended-spectrum β-lactamase producing isolates among diarrhea samples of pediatric patients.

A total of 5300 diarrheic samples from children were examined for the presence of Salmonella and Shigella species. Biochemical and microbial tests, as well as specific polyvalent antisera, were used for the identification of the bacterial species. Antibiotic susceptibility tests and extended-spectrum β-lactamase detection were conducted by disc diffusion and combination disc methods, respectively.

A total of 371 (7%) and 472 (8.9%) samples were positive for Salmonella and Shigella species, respectively. The most prevalent Salmonella isolate was serogroup D (n: 176, 47.5%). Of the Shigella isolates, 60.8% were found as Shigella sonnei and 39.2% as Shigella flexneri. The highest level of antibiotic resistance was noted among Shigella flexneri isolates. Overall, 35.7% of the Shigella flexneri isolates and 31% of the Shigella sonnei isolates produced extended-spectrum β-lactamases.

This study provided information on the prevalence and antimicrobial susceptibility patterns of Salmonella and Shigella isolates in Iran. It also indicated a high-level resistance among Shigella isolates to co-trimoxazole and ampicillin and among Salmonella isolates to nalidixic acid

Brucellosis is a zoonotic disease that causes major economic and public health problems. It is one of the most important diseases in humans and domestic animals. Hence, the exact identification of Brucella spp. is important for strategies of treatment and control. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is one of the molecular techniques characterized by amplification of deoxyribonucleic acid (DNA) sequence and restriction enzyme digestion.
This study aimed at identifying genetic polymorphisms of omp2a genes among 90 Brucella isolated from humans and animals, using the PCR-RFLP method.
Ninety Brucella spp. isolated from humans and animals in two different regions of Iran were used in this study. Biochemical tests and the Brucella omp2a (1100 bp) gene-PCR was used for identification of Brucella isolates. Polymerase Chain Reaction products were digested by restriction endonuclease enzyme pstI and gene sequencing analysis was carried out for molecular typing of Brucella strains. Therefore, genetic relatedness was revealed by a dendrogram.
Analysis of the 90 Brucella strains by biochemical tests, PCR, and PCR-RFLP methods with PstI enzyme and omp2a sequencing showed four unique RFLP Profiles (P1-P4). Seventy-nine (87.8%) of the Brucella isolates belonged to B. melitensis strain 20236. From 30 animal isolates, nine (30%) belonged to B. melitensis biovare1 and two (6.6%) to B. abortus strain. According to the RFLP dendrogram, group 1 and 2 had higher genetic relatedness similarity.
The results showed B. melitensis strain 20236 was the predominant strain among human and animal Brucella isolates. Likewise, according to dendrogram results, the PCR-RFLP technique was not able to separate human and animal species of B. melitensis from B. abortus.

Human brucellosis is a zoonotic disease caused by Brucella melitensis, Brucella abortus, and Brucella suis. Brucella causes a chronic disease, which subverts the immune defense system of their hosts. In this study, the prevalence of an important Brucella virulence determinant, PrpA, which can modulate immune response, was determined in human isolates.
Polymerase chain reaction (PCR) assay was standardized and applied to 37 isolates obtained from patient’s specimens. Primers for prpA gene were designed and evaluated using bioinformatic tools. DNA sequencing was performed for further verification.
In the 37 Brucella isolates (31 Brucella melitensis and 6 Brucella abortus), 32 (86.4%) carried prpA gene.
Presence of prpA gene in most isolates indicates the high prevalence of this gene among Iranian isolates and emphasizes its role in pathogenicity of this organism.

Brucellosis is an endemic zoonotic disease in the Middle East. This study intended to design a uniplex PCR assay for the detection and differentiation of Brucella at the species level and determining the antibiotic susceptibility pattern of Brucella in Iran.
Sixty-eight Brucella specimens (38 animal and 30 human specimens) were analyzed using PCR (using one pair of primers). Antibiotic susceptibility patterns were evaluated and compared using the E-Test and disk diffusion susceptibility test. Tigecycline susceptibility pattern was compared with other antibiotics.
Thirty six isolates of B. melitensis, 2 isolates of B. abortus and 1 isolate of B. suis from the 38 animal specimens, 24 isolates of B. melitensis and 6 isolates of B. abortus from the 30 human specimens were differentiated. The MIC50 values of doxycycline for human and animal specimens were 125 and 10 μg/ml, respectively, tigecycline 0.064 μg/ml for human specimens and 0.125μg/ml for animal specimens, and trimethoprim/ sulfamethoxazole and ciprofloxacin 0.065 and 0.125μg/ml, respectively, for both human and animal specimens. The highest MIC50 value of streptomycin in the human specimens was 0.5μg/ml and 1μg/ml for the animal specimens. The greatest resistance shown was to tetracycline and gentamicin, respectively.
Uniplex PCR for the detection and differentiation of Brucella at the strain level is faster and less expensive than multiplex PCR, and the antibiotics doxycycline, rifampin, trimethoprim-sulfamethoxazole, ciprofloxacin, and ofloxacin are the most effective antibiotics for treating brucellosis. Resistance to tigecycline is increasing, and we recommend that it be used in a combination regimen.

Infection with genital Mycoplasmas may have harm effects on the reproductive health of men, thus leading to male infertility. This study was performed to detect the prevalence of these bacteria and to study the sperm parameters in infertile men who referred to Royan Institute during 009. Semen samples were collected from 0 infertile men and divided into three sections. The first section was used for semen analysis, the second section for polymerase chain reaction (PCR) in which U4 and U5 primers were used for the amplification of the urease gene of U. urealyticum, and RNAH and RNAH primers were used for amplification of the 6S rRNA gene of M. hominis. From a total of 0 semen samples cultured, 5.5% of M. hominis and 40.5% of U. urealyticum were isolated. Evaluation of semen parameters showed a lower pH in the U. urealyticum positive group and the group which was positive for both bacteria, rather than the group which contained no bacteria (p=0.007 and p=0.000, respectively). Also, the mean sperm motility was lower in the group which was positive for both bacteria when compared with the U. urealyticum positive group (p=0.009). The results of this study show that a high percent of infertile men are infected with these bacteria which may lead to pelvic inflammatory disease (PID) and infertility, thus isolation of these bacteria in infertile couples with no clinical symptoms is necessary and can be a part of a sexual transmitted disease (STD) control program.