Acta Microbiol. Hell., Volume 71, Issue 2 (June 2026) – 9 articles

Street food is a fundamental part of the diet for millions of people, especially in Mexico, standing out for its accessibility, cost, and connection to culinary culture. Street food represents a practical alternative for the population and economic benefits for those who sell it. However, its preparation and sale can involve microbiological health hazards if proper hygiene conditions and practices are not applied during the handling, storage, and sale of products. Studies in Mexico have shown the presence of pathogenic microorganisms in street food, including coliform bacteria, Salmonella sp., Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes, among others, capable of causing foodborne illnesses. Therefore, this narrative review provides information available in various databases on street food, foodborne illnesses, causative agents, contaminants, and prevention measures. This study focuses on the Mexican context, including the socioeconomic relevance of these foods, microbiological contaminant hazards, prevention, and the regulatory framework. Although regulations and actions are in place for these foods, challenges remain related to food hygiene education for food handlers, microbiological surveillance of food, and the wide variety of products and sales outlets. Strengthening collaboration among authorities, academia, vendors, and consumers is essential to promote the availability of safe food and protect public health. Full article

Leptospirosis is among the most widespread zoonotic infections globally and is particularly prevalent in tropical settings, where it remains endemic. In Malaysia, the disease burden has increased markedly over recent decades. Severe leptospirosis can result in multi-organ dysfunction and death; however, early identification of patients at risk of a severe clinical course remains a significant challenge. This study aimed to determine independent clinical and laboratory predictors of severe leptospirosis among adults admitted to hospitals in northeastern Malaysia. A multicenter retrospective cohort study was conducted at two tertiary referral hospitals in Kelantan, northeastern Peninsular Malaysia, over a seven-year period. Adults with confirmed leptospirosis were categorised as severe or non-severe according to established clinical criteria. Group comparisons were performed using appropriate statistical tests, followed by multivariable logistic regression with internal bootstrap validation to identify independent predictors of severe disease. Of 525 patients included in the final analysis (mean age 38.1 ± 16.8 years; 65.5% male), 303 (57.7%) met criteria for severe leptospirosis and overall, in-hospital mortality was 6.5%. Common presenting symptoms (>30% of patients) included fever, myalgia, nausea, vomiting, and arthralgia. Independent predictors of severe disease identified on multivariable analysis were; age > 40 years, delayed hospitalisation (presentation after four days of symptom onset), T-wave changes on electrocardiography, conjunctival suffusion, hyponatraemia, prolonged prothrombin time, and elevated alanine aminotransferase (all p < 0.05). The predictive model demonstrated good discriminatory ability (AUC 0.794, 95% CI: 0.747–0.841). Severe leptospirosis is associated with distinct clinical and laboratory features at presentation. Early recognition of key risk factors—particularly older age, delayed presentation, and electrocardiographic abnormalities—may enable clinicians to stratify risk, initiate timely targeted interventions, and potentially reduce morbidity and mortality in this endemic setting. Full article

Effective reprocessing of surgical instruments is essential to prevent healthcare-associated infections in the field of veterinary medicine. However, chemical disinfectants are frequently used as alternatives to sterilization in small animal clinics, particularly in resource-limited settings. This preliminary exploratory study evaluated routine chemical disinfection practices and residual bacterial contamination of surgical instruments in veterinary clinics in Veracruz, Mexico. A cross-sectional study was conducted in ten small animal veterinary clinics. Samples were collected from the surgical instruments and operative surfaces immediately after routine chemical disinfection. Bacterial isolation was performed using conventional culture methods, and microbial identification was performed using MALDI-TOF mass spectrometry. Descriptive analysis and Fisher’s exact test were used to explore the association between disinfectant category and bacterial contamination. Bacterial growth was detected in 19 of the 60 samples (31.6%). The identified microorganisms included Bacillus, Staphylococcus, Pseudomonas, Acinetobacter, and Burkholderia species. Most clinics relied on low-level disinfectants, particularly benzalkonium chloride (BAC). Residual contamination was more commonly observed in clinics reporting the use of low-level disinfectants, particularly benzalkonium chloride-based products. However, these findings should be interpreted cautiously because of the exploratory observational design and limited sample size. These results suggest that routine chemical disinfection, particularly when low-level disinfectants are used, may not always achieve complete microbial elimination under real-world clinical conditions. Improved infection prevention and instrument reprocessing practices are required in veterinary clinical settings. From a One Health perspective, strengthening infection control measures in veterinary clinics may help reduce microbial circulation among animals, veterinary personnel, and the environment. Full article

Antimicrobial resistance in companion animals is a growing public health concern, yet data on last-resort resistance genes in clinical canine isolates remain scarce. This study characterizes the molecular distribution of critical resistance determinants, including mcr variants (1–5), in bacteria isolated from canine otitis externa in Ankara, Turkey. Using a combination of phenotypic disk diffusion and targeted quantitative polymerase chain reaction (qPCR), we identified Enterobacter spp., Staphylococcus spp., and Pseudomonas aeruginosa as the predominant pathogens. Notably, among Gram-negative isolates (n = 9), our results indicate preliminary evidence of mobile colistin resistance genes, particularly mcr-3 in 44.4% (4/9), and mcr-4 and mcr-5 each in 33.3% (3/9), marking the first report of these variants in canine ear infections within an urban environment. The observed notable discrepancies between genotypic carriage and phenotypic expression suggest the possible presence of silent resistance reservoirs that traditional diagnostics may overlook. These findings underscore the urgent need for molecular-integrated surveillance in veterinary clinical practice to prevent the zoonotic spread of last-resort resistance genes and to safeguard both animal and public health under the ‘One Health’ framework. Full article

Background: The clinical significance of Helicobacter pylori (H. pylori) infection in acute non-variceal upper gastrointestinal bleeding (NVUGIB) remains uncertain, particularly regarding short-term outcomes beyond rebleeding. Methods: We conducted a single-center retrospective cohort study of consecutive adults admitted with acute NVUGIB to Hatyai Hospital, Thailand, between January 2016 and December 2020. H. pylori status was determined during the index hospitalization using rapid urease testing and/or histopathologic examination of gastric biopsy specimens obtained during upper gastrointestinal endoscopy. The primary outcome was 30-day all-cause mortality. Secondary outcomes included in-hospital mortality, rebleeding, requirement of packed red blood cell transfusion, and length of hospital stay. Multivariable regression analyses were performed to adjust for potential confounders. Results: Among 933 patients, 289 (31.0%) were H. pylori-positive and 644 (69.0%) were H. pylori-negative. The H. pylori-positive group was younger, predominantly male, and had lower rates of cirrhosis and prior proton pump inhibitor use. They also more often had peptic ulcer bleeding and underwent earlier endoscopy. H. pylori positivity was independently associated with lower 30-day mortality (adjusted odds ratio 0.39, 95% confidence interval 0.18–0.84), but not with rebleeding, requirement of transfusion, or length of stay. Conclusions: H. pylori positivity was associated with lower short-term mortality in acute NVUGIB, although this finding may reflect baseline clinical differences rather than a direct effect on bleeding severity. Full article

Background: The vagina undergoes important changes across the life course that are shaped not only by hormonal transitions but also by shifts in the vaginal microbial environment. Despite growing interest in the vaginal microbiome, research has disproportionately centered reproductive-aged populations, leaving the aging vagina comparatively understudied. Objective: This article examines the aging vagina through a life-course lens, with emphasis on microbial and clinical transitions associated with midlife and older adulthood. Key Content: The article highlights menopause-related changes and approaches for reducing stigma and missed clinical opportunities. Particular attention is given to menopause-related declines in estrogen, reduced glycogen availability, increased vaginal pH, and accompanying changes in microbial balance, as well as their relationship to dryness, irritation, genitourinary symptoms, and susceptibility to adverse outcomes. The article also provides health professionals with a practical educational framework for symptom recognition, patient communication, vaginal health assessment, menopause-related education, stigma reduction, and prevention of missed clinical opportunities. Conclusions: Positioning the aging vagina within life-course and microbial-health frameworks can strengthen prevention, improve symptom recognition, and support more age-inclusive, informed, and responsive care for older women. Full article

Introduction: In recent years, antibiotic resistance has increased a lot due to inappropriate prescribing practices, presenting a critical global health challenge. There is evidence of inappropriate prescription practices by dental practitioners in Saudi Arabia. Aim: This scoping review of the published literature aimed to report on the knowledge levels and practice of antibiotic prescriptions among dental practitioners in Saudi Arabia. Methods: Three databases (PubMed, ProQuest and Scopus) were searched for relevant studies; eligible studies (primary research conducted in Saudi Arabia) were organized into three broad domains: knowledge among dental students, knowledge levels among dentists, and prescribing practice among dentists. The quality of the included studies was assessed with the Newcastle–Ottawa Scale. Results: Of the 407 search records, 22 were eligible for inclusion. Almost all studies (n = 21) were cross-sectional in design. Most of the included studies assessed the knowledge among dental students, interns and practicing dentists. Two studies were analyzing medical records and antibiotic prescribing patterns, whereas only one study was implemented as a clinical audit whose measures resulted in positive outcomes (i.e., decrease in prescriptions and increase in awareness). Most of the studies revealed a low level of knowledge and inappropriate prescription patterns among dental students and interns. Conclusions: Since only one study evaluated an interventional approach (clinical audit) that resulted in a significant reduction in inappropriate prescriptions, future research should focus on measurements and interventions to increase awareness and reduce inappropriate prescriptions. Full article

Early-onset infection caused by Streptococcus agalactiae (Group B Streptococcus, GBS) may occur during gestation or delivery and can lead to severe neonatal sepsis, meningitis, or pneumonia. Discordant GBS infections in twin gestations are rare. We report a fatal case of early-onset GBS infection in dichorionic–diamniotic twins conceived via IVF and delivered by caesarean section at 32 weeks’ gestation due to discordant fetal growth and abnormal Doppler indices in Twin A (Umbilical Artery PI = 1.4; Middle Cerebral Artery PI = 1.5). Twin A had Apgar scores of 3, 5, and 5 and rapidly developed tachycardia, respiratory distress, and systemic infection, while Twin B, with Apgar scores of 7, 8, and 9, remained clinically stable. Both infants were admitted to the NICU and underwent routine blood, urine, and cerebrospinal fluid testing. Despite the prompt initiation of parenteral ceftriaxone and respiratory support, Twin A deteriorated rapidly and died within 28 h. GBS was isolated from Twin A’s blood culture, and maternal placental tissue and high vaginal samples collected before antibiotic administration also grew GBS, with all isolates demonstrating identical antimicrobial resistance profiles. Molecular analysis revealed matching rib1 and alp2/3 gene patterns in isolates from the mother and Twin A. Maternal anovaginal immunochromatography at delivery was positive, whereas screening cultures obtained at 29 weeks’ gestation were negative. This case highlights the limitations of culture-based GBS screening in high-risk pregnancies and preterm deliveries and underscores the potential value of molecular assays and point-of-care testing to improve detection of S. agalactiae throughout pregnancy and the peripartum period. Emerging preventive strategies, including modulation of the genital microbiome and maternal vaccination aligned with WHO recommendations, may further reduce the burden of neonatal GBS disease. Full article

Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira, primarily transmitted via direct or indirect contact with contaminated rodent urine. Human disease ranges from a mild, flu-like illness to severe, life-threatening Weil’s disease. Although the incidence of leptospirosis in Greece is not high, the Ionian Islands Region, including Corfu Island, presents the highest average frequency of cases in the country. A retrospective study of 11 confirmed cases in Corfu between 2015 and 2025 was conducted. The infections recorded during this period occurred from autumn to spring, exclusively affecting male patients in rural settings; notably, 90.9% of cases were attributed to occupational exposure. No association with urban or tourist areas was found. Although the incidence of the disease decreased by 42.1% compared to the previous decade (2005–2014), the case fatality ratio reached 27.3%, considerably above the average of 2.6% in Europe (during 2010–2022). The study underscores the need for enhanced clinical awareness and targeted preventive measures in Corfu, mainly among patients with at-risk occupations. Timely preparedness is needed especially in the face of ongoing climate change. Full article