Journal of Medical Microbiology and Infectious Diseases
Year:2024 | Volume:12 | Issue:3|Papers Count:8

Cellular stress, induced by diverse factors including viral infection, reactive oxygen species (ROS), hypoxia, and toxin exposure, disrupts normal cellular function. The endoplasmic reticulum (ER) is pivotal in managing cellular stress, notably through the unfolded protein response (UPR) and ER-associated degradation (ERAD) pathways. This intricate process involves a complex interplay of transcription factors and signaling molecules. During viral infection, cells activate a multifaceted antiviral response, which is specifically modulated by both the virus type and the molecular mechanisms of the host's immune system. For instance, certain viruses like Japanese encephalitis virus (JEV) exploit multiple cellular pathways for replication and propagation. Viral infection can significantly impact cellular processes like autophagy and apoptosis, either promoting or suppressing these pathways. Thus, the cellular response to viral infection represents a dynamic interplay that can either benefit the host or be exploited by the virus for its propagation. For instance, viruses within the Flaviviridae family often preserve host cell viability during early infection to enhance replication, subsequently triggering apoptosis or other cell death mechanisms to facilitate viral dissemination. This review explores the diverse responses of infected cells to various viruses, highlighting the complex molecular strategies employed by both host and pathogen.

Introduction: Extended-spectrum β-lactamases (ESBLs) are enzymes produced by Gram-negative bacteria, which confer resistance to many β-lactam antibiotics. Among these, TEM-type ESBLs, which are typically encoded by genes on plasmids, are highly prevalent and facilitate the spread among various bacterial species, leading to resistance against penicillins and cephalosporins. Ongoing surveillance of the prevalence and characteristics of TEM-ESBLs is crucial for informing antibiotic stewardship and implementing effective infection control measures to curb their dissemination. Methods: This meta-analysis aimed to evaluate the overall prevalence of TEM-type ESBLs in the Iranian population derived from studies conducted from 2007 to 2020. Relevant articles were systematically searched in PubMed, Science Direct, Google Scholar, Biological Abstracts, Web of Science, and SID databases, encompassing research from all Iranian provinces. After applying inclusion criteria and screening titles and abstracts, a refined selection of articles was chosen for full-text review and data extraction. The data extracted were analyzed using statistical software, with subgroup analyses performed to investigate sources of heterogeneity. Results: Analysis of the 202 studies revealed an overall prevalence of 27% for TEM-type ESBLs in Iran. Subgroup analysis indicated significant regional variations, with prevalence differing markedly among provinces. The highest prevalence was observed in Qom province at 51%. By sample type, the prevalence was notably higher in urine and stool isolates, reaching 76%. Among bacterial species, Escherichia coli and Klebsiella spp. exhibited the highest prevalence of TEM-type ESBLs, with a combined rate of 43%. The peak prevalence was noted in studies from 2019, at 32%. Conclusion: The high prevalence of antimicrobial resistance, particularly among Gram-negative bacteria, represents a critical challenge to public health and calls for specific interventions to manage and reduce ESBL spread. This study highlights the significant presence of TEM-type ESBLs in Iran, demonstrating the urgent need for enhanced surveillance and targeted interventions to address the variations in prevalence across different regions and sample types. The findings emphasize the importance of implementing robust antibiotic stewardship programs and stringent infection control measures to mitigate the dissemination of TEM-type ESBLs and preserve the effectiveness of β-lactam antibiotics.

Introduction: Antibiotic-resistant Pseudomonas aeruginosa has been designated by the World Health Organization (WHO) as a critical priority pathogen, highlighting the critical need for developing new strategies, particularly prophylactic measures. This research focuses on incorporating highly antigenic elements from essential, surface-exposed outer membrane proteins of P. aeruginosa to design a polypeptide-based subunit vaccine capable of inducing a strong immune response, using immunoinformatics approaches. Methods: Ten essential outer membrane proteins of P. aeruginosa were analyzed using three online servers (ABCpred, BCPREDS, and LBtope) to predict B-cell epitopes and the IEDB server to predict CD8+ and CD4+ T-cell epitopes. The predicted epitopes were then assessed for physicochemical properties, allergenicity, and toxicity using relevant web servers. A vaccine construct incorporating the selected epitopes and an adjuvant was designed, and its 3D structure was modeled to study its interaction with Toll-like receptor-4 (TLR-4). Results: The final vaccine construct consisted of a 478-amino acid polypeptide incorporating 5 CD8+ T-cell, 5 CD4+ T-cell, and 15 B-cell epitopes. In silico analysis predicted the vaccine construct to be immunogenic, non-toxic, non-allergenic, and possess favorable physicochemical properties. Molecular docking simulations predicted strong binding affinity between the vaccine construct and TLR-4, suggesting its potential to elicit a robust immune response. Conclusion: These in silico analyses suggest that the designed subunit vaccine is potentially safe and effective against P. aeruginosa. However, experimental validation is necessary to confirm these predictions.

Introduction: Green fluorescent protein (GFP) and its variants are pivotal in tracking gene expression across various gene delivery systems. While GFP is typically employed for intracellular reporting, it can be modified to display on cell surfaces for labeling. Previous research indicates GFP might have immunogenic effects, notably enhancing tumor-specific T cell responses. This study explores the immunostimulatory differences between enhanced GFP (EGFP) and the supercharged variant, +36 GFP. Methods: Recombinant EGFP and +36 GFP proteins were generated using an Escherichia coli expression system. Murine bone marrow-derived dendritic cells (BMDCs) were generated using established protocols. Splenocytes were isolated from murine spleens via mechanical disruption and red blood cell lysis. The RAW 264.7 macrophage cell line was cultured in complete DMEM medium. Immune cells were then incubated with varying concentrations of EGFP and +36 GFP, separately, for 48 h. Cytokine levels (IFN-γ, TNF-α, IL-10) were quantified using sandwich ELISA.

Introduction: Viral hepatitis represents a significant challenge to public health worldwide. Women living with HIV are at heightened risk of co-infection with hepatitis B and C due to their increased risk of exposure to bloodborne pathogens through medical interventions, potentially leading to severe health outcomes, including increased morbidity and mortality, and public health impacts through maternal transmission. This study aimed to estimate the prevalence of hepatitis B and C virus co-infection among women living with HIV attending the ART clinic in Modibbo Adama University Teaching Hospital, Yola, Nigeria. These findings will inform the development and improvement of testing, vaccination, and treatment programs to enhance health outcomes and quality of life for this population. Method: A cross-sectional study was conducted from January 2023 to September 2023 using a convenience sampling method to recruit 360 women aged 18 years and above attending the ART clinic. Data on socio-demographic characteristics and potential risk factors for HBV/HCV infection were collected with a structured questionnaire. The seroprevalence of HBsAg and anti-HCV antibodies was determined with Rapid Diagnostic Test (RDT) strips from Micropoint. Results: Among the 360 HIV-positive women tested, 9.2% (33) were co-infected with HBV, 2.2% (8) were co-infected with HCV, and 0.3% (1) had co-infection with HBV, HCV, and HIV. The prevalence of HBV co-infection was highest among women aged 39-48 (9.6%), while HCV co-infection was most prevalent in those aged 49 and above (3.4%). Logistic regression analysis showed that blood transfusion and having multiple sexual partners were significantly associated with HIV/HBV co-infection (P-value = 0.002). Conclusion: This study identified a notable prevalence of HBV (9.2%) and HCV (2.2%) co-infection among women living with HIV, underscoring the public health significance due to the potential for increased morbidity and mortality. Further studies should employ molecular techniques like PCR to confirm active infections and assess viral loads. This information is crucial for guiding treatment decisions and improving clinical outcomes for this vulnerable population.

Introduction: Postbiotics derived from the natural oral microbiome offer a potential solution for chemotherapy-induced oral dysbiosis by restoring microbial balance. These compounds hold promise for managing oral infections, particularly in vulnerable populations, by restoring microbial balance, directly inhibiting pathogen growth, and promoting a healthy mucosal immune response. This study evaluates the antimicrobial activity of postbiotics derived from aerobic oral bacteria against Staphylococcus aureus and assesses their cytotoxicity in human cells, contributing to the development of new therapeutic strategies for oral infections. Methods: Specific strains of aerobic oral bacteria were isolated and cultured in nutrient broth at 37°C in a 5% CO2 atmosphere. After 24 h of incubation, the supernatant containing postbiotics was collected and centrifuged, followed by filtration to isolate the postbiotics. The antibacterial activity of these postbiotics was assessed against S. aureus isolated from oral wounds using the agar well diffusion method on Mueller-Hinton agar plates. In parallel, the cytotoxic effects on Normal Human Dermal Fibroblasts (NHDF) were evaluated through MTT viability assays to measure metabolic activity, and SYBR Green staining to quantify DNA content, and assess cell membrane integrity. Statistical analysis was performed using one-way ANOVA followed by Tukey's post-hoc test, with significance set at P < 0.05. Results: Postbiotics exhibited significant antimicrobial activity against S. aureus, as evidenced by a mean zone of inhibition of 17.0 mm (±1.4 mm), while no inhibition was observed in saline controls. Furthermore, postbiotics treatment resulted in NHDF cell viability of 94% (±1.6%) compared to the untreated controls 75.2% (±0.7%); P < 0.0001, demonstrating their biocompatibility. Conclusion: This study demonstrates the promising therapeutic potential of postbiotics for combating opportunistic oral infections, exhibiting negligible cytotoxicity towards host cells. Future research will explore isolating and identifying the active components of these postbiotics and evaluating their efficacy in vivo models and human oral cell lines.

Introduction: Acromegaly is often associated with alterations in carbohydrate metabolism, ranging from impaired glucose tolerance to overt diabetes mellitus (DM). This study aimed to evaluate the serum concentrations of TNF-α and IL-10, along with other biochemical parameters, in patients with acromegaly and concomitant diabetes. Furthermore, we sought to investigate the associations between these parameters. Additionally, this study investigated the prevalence of Cytomegalovirus (CMV) infection and its potential correlation with TNF-α, IL-10, and other biochemical parameters in this patient population. Methods: Serum concentrations of TNF-α and IL-10 were measured in 50 patients with acromegaly and concomitant diabetes and 50 healthy controls using commercially available ELISA kits. CMV DNA was detected in serum samples using a qualitative PCR assay targeting the CMV late antigen gp64 gene. Results: Patients with acromegaly and concomitant diabetes exhibited significantly higher levels of IGF-1, insulin, HOMA-IR, cholesterol, triglycerides, LDL, VLDL, ALT, AST, bone-specific alkaline phosphatase (BALP), TNF-α, and IL-10 compared to the control group (all P<0.05). CMV infection was detected in 1.9% (1/50) of the healthy control group and 23.5% (12/50) of the acromegaly and diabetes group. Within the acromegaly and diabetes group, CMV-positive patients had significantly higher levels of TNF-α and IL-10 compared to CMV-negative patients (both P<0.05). Conclusion: This study demonstrated a significant association between elevated levels of TNF-α and IL-10 and acromegaly with concomitant diabetes. Further research is needed to determine if these cytokines play a causal role in the pathogenesis of these comorbidities. The observed increase in ALT, AST, and BALP levels in patients suggests potential liver and bone involvement in acromegaly with concomitant diabetes. Moreover, a higher prevalence of CMV infection was observed in patients with acromegaly and concomitant diabetes compared to healthy controls, suggesting a potential link between CMV infection and this patient population. Further research is warranted to elucidate the nature of this association and its potential clinical implications.

Introduction: Nocardiosis is a globally recognized opportunistic infection that predominantly affects immunocompromised individuals, leading to a diverse range of clinical manifestations, from cutaneous to severe systemic forms. The similarity of pulmonary nocardiosis symptoms to those of pulmonary tuberculosis often leads to misdiagnosis, presenting a significant diagnostic challenge for clinicians. We present an illustrative case of a 48-year-old male, newly diagnosed with HIV, who exhibited symptoms initially suggestive of pulmonary tuberculosis but was subsequently diagnosed with pulmonary nocardiosis. Methods: Bronchoalveolar lavage (BAL) fluid samples were obtained and subjected to microbiological culture, Gram staining, and modified acid-fast (Ziehl-Neelsen) staining for the identification of Nocardia species. Results: Gram staining of BAL fluid revealed thin, branched, beaded, filamentous, Gram-positive bacilli. Modified acid-fast staining identified branching acid-fast bacilli (1-2 organisms per high-power field (HPF)), consistent with Nocardia. Diagnosis of Nocardia is crucial as it necessitates targeted therapy, particularly in immunocompromised hosts. Nocardia was cultured after one week, highlighting its slow growth characteristic, which can delay diagnosis and treatment. The patient was commenced on trimethoprim-sulfamethoxazole (800/160 mg four times daily), showing significant clinical improvement within two weeks. After 12 months of treatment, there was complete resolution of symptoms, radiological improvement, and normalization of laboratory parameters, indicating successful treatment of pulmonary nocardiosis. Conclusion: Pulmonary nocardiosis must be considered in immunocompromised patients with persistent respiratory symptoms. Comprehensive imaging and bronchoscopy with BAL are pivotal for effective sample collection and accurate laboratory diagnosis. Modified Ziehl-Neelsen staining is critical for the definitive identification of Nocardia infection. Early and proactive screening in high-risk groups, such as HIV patients, cancer patients, or organ transplant recipients, is crucial for the prompt initiation of targeted therapy, typically with trimethoprim-sulfamethoxazole, to improve outcomes.