Jundishapur Journal of Microbiology
Volume:15 Issue: 2, Feb 2022

Pseudomonas aeruginosa (P. aeruginosa) is a nosocomial opportunistic bacterium especially in infection wards and among patients with burns. In this study, we dealt with molecular investigation of gene cassettes of Class I integron and its relationship with multiple drug resistances in clinical samples of P. aeruginosa isolated from Babol hospitals (north of Iran).

The aims of this study were detecting the frequency of int1 and gene cassettes in clinically isolates of P. aeruginosa.

In this study, from 75 clinical samples, 30 strains were identified via specific biochemical methods. After determining antibiotic susceptibility using disk diffusion and agar dilution, the frequency of Class I integron (intI) gene and its gene cassettes were determined via polymerase chain reaction (PCR) method.

The highest resistance rate was related to cefotaxime, ampicillin, and nitrofurantoin by disk diffusion and agar dilution. The molecular analysis showed that 60% of isolates had the intI genes. The frequency of aadB, dfrA1 and bla-OXA30 genes were 61%, 66% and 33%, respectively.

The high resistance of Pseudomonas isolates is due to the presence of intI and its gene cassettes. Thus, considering their high resistance to the antibiotics of cefotaxime, gentamicin, ampicillin, and imipenem in hospitals, selecting suitable drugs or generally changing the treatment course of patients is possible to prevent the spread of resistance developing genes and development of nosocomial infections. Keywords: Pseudomonas aeruginosa, Class 1 integron, Gene Cassette, Antibiotic resistance.

Urinary Tract Infections (UTI) can depend on many factors such as bacteria, Escherichia coli and Klebsiella pneumoniae in particular. The high rate of carbapenem resistance in Enterobacteriaceae has become a global therapeutic problem.

The aim of this study was the investigation of OXA-23, OXA-24, OXA-40, OXA-51 and OXA-58 genes in uropathogenic isolates of E. coli and K. pneumoniae.

All 500 uropathogenic isolates of E. coli and K. pneumoniae have been segregated from patients at Milad Hospital, Tehran, Iran. Antibiotic susceptibility testing was performed using a strip-test method and the confirmation of carbapenem-resistant isolates were performed using an automated antimicrobial susceptibility testing system. OXA genes were determined by multiplex PCR assay. Moreover, molecular typing of isolates was performed by MLVA.

Out of 500 isolates, 40 (8%) isolates were detected as carbapenem-resistant, including 13 E. coli and 27 K. pneumoniae. All carbapenem-resistant isolates were ESBL-producing and resistant to ceftriaxone, ciprofloxacin, meropenem, ceftazidime and amoxicillin-clavulanate. Moreover, 46.1% and 26% of carbapenem-resistant E. coli and K. pneumoniae isolates had a gene encoding β-lactamase associated with the OXA-23-like group. E.coli and K. pneumoniae isolates were divided into 2 and 3 MLVA patterns, respectively.

This is the first report of OXA-51, 58 and 24 carbapenemases in clinical isolates of E. coli and K. pneumoniae isolated from urinary tract infections in Iran. Significant differences in OXA-51, 58 and 24 genes were found in carbapenem-resistant and carbapenem-susceptible E. coli and K. pneumoniae isolates. Molecular typing of isolates has suggested vertical transmission of resistant genes.

Brucellosis is an inflammatory disease that may affect any organs or systems, and may present with various nonspecific clinical manifestations. Because of the obstacles in the clinical and laboratory diagnosis of brucellosis, there is a need to identify specific, practical and reliable diagnostic markers.

The aim of this study was to investigate the predictive value of novel and traditional inflammatory markers for the diagnosis of brucellosis.

The demographic characteristics and laboratory results of 55 patients with confirmed brucellosis and 60 healthy controls were analyzed and compared. Blood culture was performed using BacT/ALERT 3D (bioMérieux, France) automated system. The presence of Brucella antibodies was detected by both Brucellacapt test (Vircell, Granada, Spain) and Brucella Coombs gel test (Across Gel, Dia Pro, Turkey). Complete blood count, erythrocyte sedimentation rate (ESR) and biochemical analyzes were also performed.

Compared with healthy controls, the patients with brucellosis had significantly higher high sensitive C-reactive protein (hsCRP), hsCRP to albumin ratio (CAR), ESR, monocyte, monocyte to high-density lipoprotein cholesterol ratio (MHR), aspartate aminotransferase, creatinine levels, and significantly lower mean platelet volume, lymphocyte to monocyte ratio, albumin, total cholesterol, high-density lipoprotein cholesterol levels (p<0.05). There was no significant difference between two groups in terms of leukocyte, neutrophil, lymphocyte, hemoglobin, red blood cell distribution width, platelet, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, glucose, alanine aminotransaminase, blood urea nitrogen, triglyceride, low-density lipoprotein cholesterol levels (p>0.05). Positive correlations were observed between CAR, hsCRP, ESR and MHR levels (p<0.05).

This is the first study evaluating the predictive role of CAR and MHR in the diagnosis of brucellosis. The data revealed that CAR and MHR can be used as markers of systemic inflammation in patients with brucellosis. More comprehensive studies are required to support our findings.

The worldwide prevalence of Helicobacter pylori is about 50%. This bacterium needs a number of virulence factors for pathogenesis. This study aimed to determine the prevalence of virulence genes (ureB, cytotoxin-associated gene A [cagA], and vacuolating cytotoxin [vacA]), as well as the antigenic profile in H. pylori strains.

Eighty-five patients with abdominal pain, including 46 H. pylori-positive (Hp+) and 39 H. pylori-negative (Hp-) cases, were enrolled in this study. The serum levels of interleukin (IL)-17F, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ) cytokines were measured by multiplex kits and flow cytometry. After molecular identification by the ureC gene, vacA, cagA, and ureB genes were detected by polymerase chain reaction (PCR). Finally, after antigenic extraction, the whole-cell protein was exhibited by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE).

The prevalence of vacA, ureB, and cagA genes were 91.3%, 67.39%, and 50%, respectively. The frequency of genes and cell surface antigens were not significantly different based on the gastritis severity (p > 0.05). IL-17F significantly (p = 0.046) increased in the presence of 19.5 kDa (outer membrane protein [OMP]). Moreover, the OMP antigen significantly enhanced immunoglobulin A (IgA; p = 0.013). In the presence of the 66-kDa (ureB) antigen, the serum level of IFN-γ increased (p = 0.041). Finally, the CagA protein led to increased IgG antibody levels (p = 0.027).

Early detection of H. pylori infection can play a crucial role in managing it. Our results suggest that IL-17F, TNF-α, and IFN-γ cytokines could be diagnostic markers. However, further studies are required to fully investigate this suggestion.

Streptococcus agalactiae or group B streptococcus (GBS) is a prominent cause of severe neonatal infections. GBS is a part of the intestinal and vaginal normal flora. Maternal colonization is recognized as the main path of GBS transmission. GBS is a pathobiont that changes from a non-symptomatic mucosal carriage state to a significant bacterial pathogen, causing major infections.

This study aimed to investigate the concomitant presence of major colonization genes, including ftsA, ftsB, lmb, and sfbA, and to determine the genetic relatedness of clinical GBS isolates.

The GBS isolates were obtained from urinary and placental samples of pregnant women with a urinary tract infection, who were admitted to a hospital in Tehran, Iran. The presence of some major colonization factors was investigated via multiplex PCR assay. Genotyping of the isolates was performed using the BOX-PCR fingerprint technique with a BOX-A1R primer. Next, the data were analyzed using the UPGMA method and the coefficient of Jaccard in NTSYS software.

A total of 60 GBS isolates were examined in this study. The concomitant presence of target colonization genes was observed in all isolates. The BOX-PCR discriminated GBS isolates into six different genetic clusters at a 60% cutoff point. The majority of isolates (80%) from both clinical samples were clustered into genotypes 2, 6, and 4, while the rest (20%) were distributed equally into three different genotypes.

Determining the colonization associated genes and genetic polymorphism in a different geographical area provides the epidemiological basis for the prevention of GBS infections in pregnant women and infants.

Mycoplasma genitalium is a sexually transmitted human pathogen, causing numerous reproductive tract diseases in both genders. MG428 is a positive regulator of surface exposure protein gene recombination and an alternative sigma factor of M. genitalium.

We extracted and cloned the MG428 gene and bioinformatics analyzed its protein structure in this study.

We designed specific primers based on the MG428 gene sequence of M. genitalium. The MG428 gene was amplified using PCR techniques and ligated into the pGEM-T easy vector. The positive clones were verified by DNA sequencing. The MG428 protein biological characteristics and structure was analysed by biological characteristics.

The MG428 gene of M. genitalium has a length of 513 bp and encodes 171 amino acids. No coiled-coil conformation, possible transmembrane helices, or signal peptide was found in the MG428 protein. The MG428 protein was located in the nucleoid of bacteria, and its 3D structure was similar to that of the sigma-H factor of Pseudomonas aeruginosa. A total of 14 B cell epitopes in MG428 were predicted.

We successfully cloned the MG428 protein of M. genitalium and predicted its structure and function. The results of this study could provide a research direction for medicine screening against M. genitalium.