Infection, Epidemiology And Medicine
Volume:8 Issue: 4, Autumn 2022

The ever-increasing incidence of multidrug resistance in ESBL-producing Pseudomonas aeruginosa is one of the most serious public health threats. This study aimed to investigate the antibiotic resistance profile and molecular characteristics of ESBL-producing P. aeruginosa isolates.

Antimicrobial susceptibility testing was performed for 120 P. aeruginosa clinical isolates using the Kirby-Bauer disk diffusion and broth microdilution assays. Combined disk test (CDT) was applied to screen for ESBL production among P. aeruginosa isolates. PCR assays determined the presence of blaGES, blaPER, and blaVEB genes in all isolates.

The clinical isolates of P. aeruginosa showed the highest resistance to cefotaxime (86.7%) and gentamicin (65.8%). Of 120 P. aeruginosa isolates, 60.8% were MDR, and 53.3% were XDR. The prevalence of these strains was significantly higher in hospitalized patients than in out-patients (p<.001). Also, 58 P. aeruginosa strains (48.3%) were considered as phenotypic ESBL producers. Furthermore, 15, 35, and 24.2% of P. aeruginosa isolates harbored blaGES, blaVEB, and blaPER, respectively. The incidence of MDR (71.4% vs. 41.9%, p= .001) and XDR (63.6% vs. 34.9%, p= .002) was significantly higher in ESBL-producing P. aeruginosa isolates compared to non-ESBL producers. The highest incidence rate of MDR was reported in blaVEB gene-positive P. aeruginosa isolates (95.2%), followed by isolates harboring blaPER (79.3%) and blaGES (55.6%) genes.

This study findings show a high prevalence of MDR ESBL-producing P. aeruginosa isolates, indicating the importance of correct identification of these superbugs and judicious use of various antibiotics to prevent their spread.

Helicobacter pylori infections vary in severity and virulence in different populations for various reasons. There are different H. pylori strains with varying degrees of virulence. The genetic diversity of H. pylori strains in gastritis patients in different areas has not been well understood. This study aimed to evaluate the prevalence rate and different genotypes of H. pylori strains in clinical specimens of patients with gastritis in Ilam, Iran.

Saliva and gastric biopsy samples were collected from 81 patients (55 males and 26 females in the age range of 20 to 90 years) referring to Ilam medical centers. After DNA extraction, the prevalence of H. pylori as well as vacA, cagA, and ureC genes was evaluated using PCR, and then each vacA-positive sample was further evaluated for m1m2 and s1s2 variants.

The cagA and vacA genes were found in 27 (71%) and 36 (94.7%) H. pylori-positive samples, respectively. The cagA gene was detected in patients with gastric pain (44.4%) and anorexia (18.51%). Also, the results showed that the vacA s2m2 genotype and m2 allele were present in 32.9% of H. pylori isolates. Moreover, s2m2 and s1m2 genotypes were detected in 42.1 and 26.3% of vacA-positive samples, respectively. The lowest frequency was related to the m1 allele (17.18%).

This study results indicate a plausible relationship between the presence of some genotypes of H. pylori and the progression of gastritis, suggesting these markers as promising biomarkers to predict the disease severity.

This study was done to evaluate the distribution of virulence-associated genes and antibiotic resistance in avian colibacillosis-causing Escherichia coli (E. coli) isolates.

In this study, 122 E. coli strains isolated from colibacillosis-suspected chickens in commercial broiler poultry farms (Guilan province, Iran) were examined for the presence of 12 virulence genes (hlyF, iroN, iss, iutA, ompT, astA, tra, sfa-foc, papC, fimH, cvi/cva, and Tia) using polymerase chain reaction (PCR). Antimicrobial susceptibility assessment was performed for the isolates using disc diffusion method against 19 antibiotics.

The fimH, iut, tra, iss, iroN, hly, and ompT genes were detected as the most prevalent genes among colibacillosis-causing isolates (more than 70%), while sfa-foc (S fimbriae and F1C fimbriae subunits) had the lowest frequency among colibacillosis-causing E. coli isolates (3.28%).

Virulence-associated genes were frequently detected in avian pathogenic E. coli strains. These findings could help better understand the pathogenicity potential of E. coli in poultry. Preventative measures are necessary to reduce food and environmental contamination with avian E. coli strains.

Blastocystis is a common intestinal parasite among humans and various animals, including birds. The parasite has at least 28 known subtypes, of which nine subtypes have been reported in humans and livestock. The aim of this study was to determine the prevalence rate and common subtypes of Blastocystis hominis in pigeons and their owners in Tafresh city.

The present study was designed and conducted as a case control in Tafresh city (Markazi province) during 2020-2021. For this purpose, fecal samples were collected from pigeons (300 samples) and their owners (100 samples). Stool samples were studied by microscopic methods (direct and trichrome staining examinations). Then positive stool samples were examined by PCR method through amplification of 18 SrRNA gene and sequencing.

In direct stool examination, 39 (13%) out of 300 pigeon samples and 18 (18%) out of 100 human fecal samples were found to be positive for Blastocystis. In trichrome staining method, 18% of human samples and 15% of pigeon samples were positive, while in PCR test, only 2.5% of pigeon samples and 4.5% of human samples were Blastocystis positive. The alignment results showed that all Blastocystis strains isolated in this study (100%) were similar to subtype 3.

Due to the low prevalence rate of this parasite in pigeons in Tafresh city, their owners are less likely to be infected with this parasite. Therefore, the relative transmission risk of this parasite from pigeons to humans is low.

Nowadays, excessive use of fungal drugs has led to the development of drug-resistant fungi, making it necessary to find natural and herbal antifungal agents. This in-vitro study aimed to evaluate the interactions of Satureja hortensis and Carum carvi essential oils together and each essential oil with fluconazole against Candida albicans ATCC-10231.

In this study, antifungal properties of different concentrations of S. hortensis (0.0244-1.56 μL/mL) and C. carvi (0.39-25 μL/mL) were investigated by broth-microdilution method based on CLSI M27-A3 and M27-S4 standard documents. The interactions of essential oils together and each essential oil with fluconazole were evaluated by checkerboard assay. Then using the ΣFIC index, the interaction results were interpreted.

S. hortensis essential oil showed higher antifungal activity than C. carvi essential oil. (MIC/MFC: S. hortensis: 1.56/3.12 μL/mL and C. carvi: 12.5/25 μL/mL). The interaction between S. hortensis essential oil and fluconazole was on the synergic and additive borderline (FICI=0.508), the interaction between C. carvi essential oil and fluconazole was additive (FICI=0.62), and C. carvi and S. hortensis essential oils showed no interaction together (FICI=2.015).

The essential oils of S. hortensis and C. carvi separately exhibited powerful antifungal activities. The use of S. hortensis essential oil at a very low concentration along with fluconazole caused an interaction very close to synergy and increased fluconazole antifungal activity. Therefore, S. hortensis is a potential candidate for combined use with fluconazole to treat C. albicans related diseases.

In this research, an attempt was made to identify Candida isolates collected from women with suspected vulvovaginal candidiasis using single Multiplex PCR reaction as a swift and valid method. Beside, this method was compared with phenotypic methods.

In this study, 250 vaginal swabs were collected from patients referring to obstetrics and gynecology specialists. In addition to phenotypic methods, multiplex PCR designed by species-specific primers was performed to identify Candida isolates in a single reaction. Descriptive statistics were analyzed by t-test and Chi-square test in SPSS software (Ver. 22) (p< .05).

According to the results, 92 positive samples were diagnosed using the culture method. Four species were identified by culturing the specimens on CHROM agar. The most common Candida species isolated was C. albicans (54.3%), followed by C. parapsilosis (28.2%), C. glabrata (17.4%), and C. krusei (1.0%). The most common Candida spp. identified by Multiplex PCR method were C. albicans (50.0%), C. glabrata (33.7%), and C. parapsilosis (6.2%). Also, three mixed infections with C. albicans and C. glabrata as well as C. albicans and C. parapsilosis were identified

In comparison to phenotypic methods, considering the cost-effectiveness of PCR methods, the single multiplex PCR reaction was shown to be efficient in epidemiological studies on pathogenic species.

There is a remarkable similarity between Herpesvirus papio 2 (HVP2) infecting baboons and human simplex virus (HSV) in terms of molecular biology, protein functions, and resulting infections. However, no definitive therapy exists, and the available drugs only improve the clinical signs of recurrent or asymptomatic infections. This research results may be useful for studies on the quest for HVP2 curative and preventive drugs in baboon models. Later, a similar study could be done on HSV in humans.

A total of 60 baboons were sampled from six different counties in Kenya. Of these, 51 cases were wild caught from five counties, and nine cases were from the Institute of Primate Research (IPR) colonies designated as captive baboons. Oral and genital swabs were collected for analysis. The trigeminal ganglia of three study subjects were also aseptically sampled. Polymerase chain reaction test was used to determine the prevalence of HVP2. HVP2-positive samples were sequenced and aligned to GenBank sequences using BLAST to identify specific circulating strains and generate phylogenetic relationships. DnaSP6 was used for genetic diversity analysis.

Among 60 baboons studied, 65% were positive for the virus. One strain, A951, was identified as the prevalent strain. Extremely low fixation index values (Fst) were recorded, showing low genetic diversity within and between subpopulations.

The identified strain was non-pathogenic but could be clinically manifested as painful sores on the host's mucosal membranes and cause stillbirths. The virus prevalence was 75.86% in genital samples and 54.86% in oral samples, indicating that oral transmission is less common than genital transmission.

SARS-COV-2 infection is not always correlated with protection. Antibody seroprevalence in unvaccinated individuals, which is usually measured by N-specific antibodies, is not necessarily correlated with protection, while antibodies against S protein show a better correlation with protection due to its neutralizing epitopes. In this study, we tried to improve our conception of the hidden perspective of SARS-COV-2 in epidemiological reports and investigate anti-S antibody prevalence among anti-N antibody-positive asymptomatic and mildly symptomatic patients.

Blood samples were collected from asymptomatic or mildly symptomatic volunteer participants and symptomatic hospitalized patients with negative PCR results from May 30 to June 17, 2020. Detection of SARS-COV-2 antibodies was done using an ELISA kit targeting N or S protein.

Totally, 716 samples from volunteer participants and 81 samples from symptomatic hospitalized patients with negative PCR results were evaluated. The test performance-adjusted seroprevalence (95% CI) of SARS-COV-2 antibody was 17.3% (8.8-25.8%) for anti-N IgG in volunteers and 25.5% (12.8-39.7%) for anti-N and anti-S IgM in hospitalized patients. Among anti-N IgG positive infected individuals, 49.2% (21.4 and 78.8%) were anti-S antibody positive.

The results showed that SARS-COV-2 infection sometimes occurs in individuals without symptoms or with mild symptoms, but in more than half of them, the produced antibody is not protective. The findings of hospitalized patients showed that the combination of IgM assay with real-time PCR improved the disease diagnosis by more than 25% in cases with negative molecular test results.

  Although conventional therapies have played an essential role in the treatment of many diseases, emerging diseases require new treatment methods with less complications. Therefore, it is important to develop an effective vaccine for infections caused by the coronavirus to prevent mortality and create immunity the community.

In this research bioinformatics tools were used to design a vaccine against the  M membrane protein of SARS-CoV-2.  A total of 27 epitopes confined to B cells and MHC I and II alleles were structurally constructed in M protein for immune stimulation and antibody recognition which were used in the construction of a chimeric peptide vaccine .

The vaccine was predicted to be a stable, antigenic, and non-allergenic compound. TRL5/vaccine complex  analysis  and docking simulation indicated a sufficiently stable binding with appropriated receptor activation. The immune response simulation following hypothetical immunization indicated the potential of this vaccine to stimulate the production of active and memory B cells, CD8 + T and, CD4 + T cells, and effective immunological responses induced by Th2 and Th1.

  The analysis of in-silico processes showed that the vaccine structure induced high antigenicity and good cellular immunity in the host body and stimulates various immune receptors such as TLR5, MHC I, and MHC II. Vaccine function was also associated with an increase in IgM and IgG antibodies and a set of Th1 and Th2 cytokines. But the final confirmation of the effectiveness of the designed vaccine requires  clinical processes.

For centuries, arboviruses have been spreading like a wildfire across the world, especially in developing countries like Nigeria with inadequate diagnostic and disease surveillance facilities, causing infinite death and suffering in human and animal populations. Therefore, this study aimed to discuss the impact of arboviruses on public health with a focus on Nigeria and West Africa.

About 100 research articles were downloaded from online journal databases such as PubMed, Google Scholar, and African Journals OnLine (AJOL) with the following keywords: arboviruses, emerging, public health importance, Nigeria, and Africa.

A total of 50 articles were used to write this review after a thorough screening. Arboviral infections caused by yellow fever, Rift Valley fever, West Nile, dengue, and chikungunya viruses were reported in Nigeria and discovered based on seroprevalence studies.

Hemorrhagic fever, abortion, neonatal death, and decreased production in livestock are the most obvious features of arboviral infections; therefore, they are of public health and economic importance. Thus, there is a need to strengthen and refurbish the healthcare system in the country by employing preventive and control measures, vaccination campaigns, and other strategies to prevent the occurrence of diseases in the future.