Search Results (669)

Staphylococcus aureus causes infections ranging from skin and soft tissue infections to life-threatening systemic disease. The convergence of virulence determinants with antimicrobial resistance, particularly in methicillin-resistant S. aureus (MRSA), complicates management. In the United Arab Emirates (UAE), S. aureus is a major contributor to community- and hospital-acquired infections, and regional surveillance from the Gulf Cooperation Council has documented a shift toward community-associated MRSA lineages. Despite this clinical burden, granular molecular epidemiological data from the UAE remain scarce. Fifty consecutive S. aureus clinical isolates were obtained from Thumbay Laboratories, Ajman, UAE (October 2022–August 2023). Identification and antimicrobial susceptibility testing against 23 agents were performed on the MicroScan WalkAway system. Five virulence genes, namely mecA, Panton-Valentine leukocidin (PVL; lukF-S), exfoliative toxins A (eta) and B (etb), and toxic shock syndrome toxin (tst), were detected by conventional PCR. PVL was the most prevalent virulence gene (48%, 24/50), detected exclusively in pus isolates. mecA carriage, confirming MRSA, was identified in 44% (22/50), with PVL–mecA co-occurrence in 22% (11/50). eta was present in 6% (3/50), and etb and tst each in 2% (1/50). Resistance was highest for ampicillin and penicillin (86% each), while full susceptibility (100%) was retained for vancomycin, linezolid, daptomycin, teicoplanin, rifampin, Synercid, and trimethoprim. mecA carriage was significantly associated with resistance to amoxicillin, clavulanate, ampicillin, imipenem, penicillin, oxacillin, azithromycin, erythromycin, and ciprofloxacin (p < 0.05). This study provides the first integrated molecular characterization of key S. aureus virulence determinants, along with a comprehensive antimicrobial susceptibility profile in the UAE. The high PVL prevalence and substantial MRSA burden highlight the need for structured regional surveillance and antimicrobial stewardship, while retained susceptibility to last-resort agents offer actionable guidance for empirical therapy. Full article

Enterobacteriaceae are a diverse family of Gram-negative, rod-shaped, facultatively anaerobic bacteria that serve as important indicators of food safety. Many species within this family, including common foodborne pathogens, are major contributors to both community- and hospital-acquired infections. The widespread use of antibiotics in agriculture has facilitated the emergence and dissemination of antimicrobial-resistant bacteria in food products, livestock, and the environment. This study investigated the prevalence and genomic characteristics of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolated from food sources in Saudi Arabia. A total of 160 isolates preserved in the Saudi Food and Drug Authority (SFDA) biobank were screened for antimicrobial resistance using indicator β-lactam antibiotics according to CLSI guidelines. Phenotypic screening indicated that Escherichia coli O145, E. coli O157, Klebsiella pneumoniae, and Cronobacter sakazakii isolates were not ESBL producers. In contrast, ESBL production was detected among Salmonella spp. isolates, and 13 confirmed ESBL-producing Salmonella isolates were subsequently subjected to whole-genome sequencing (WGS). Genomic analysis identified the ESBL gene blaCTX-M-65, along with multiple antimicrobial resistance determinants, virulence-associated genes, and plasmid replicons, predominantly belonging to the IncFIB and IncX families. These findings provide important insights into the occurrence of ESBL-producing Enterobacteriaceae in food sources and highlight the value of integrating phenotypic and genomic approaches for antimicrobial resistance surveillance within food safety systems. Full article

Community-acquired pneumonia is one of the main causes of morbidity and mortality due to infections worldwide. This has led to the study of the use of corticosteroids as adjunctive therapy, which has shown an inclination to provide clinical benefits. However, controversy persists regarding the use of one corticosteroid over another Objectives: Evaluate the outcomes associated with the use of hydrocortisone versus methylprednisolone in patients with community-acquired pneumonia. Methods: We conducted a multicenter retrospective cohort study that included hospitalized adults diagnosed with CAP at two high-complexity clinics in Colombia between 2010 and 2020. Propensity score matching was used in a 1:1 ratio to balance the baseline characteristics between the hydrocortisone and methylprednisolone groups. The primary outcome was 30-day mortality. Secondary outcomes included septic shock, vasopressor use, admission to the intensive care unit, mechanical ventilation, and other hospital outcomes. Survival analyses were performed using Kaplan–Meier curves and estimates of the average treatment effect, as well as subgroup analyses according to the dose and duration of treatment. Results: The study initially included 366 patients, with significant baseline differences between groups. After matching, an adjusted cohort of 168 patients (84 per group) was obtained, with an adequate balance of clinical, paraclinical, and severity-related variables. No statistically significant differences were found in 30-day mortality between patients who received hydrocortisone and those who received methylprednisolone before or after matching. Additionally, no differences were detected in the secondary clinical outcomes. Survival analyses revealed no differences according to corticosteroid type, treatment duration, or administered dose. Conclusions: In this retrospective propensity-score-matched cohort study, no differences were observed in 30-day mortality or other clinical outcomes between hydrocortisone and methylprednisolone in patients with community-acquired pneumonia. Full article

Human intestinal nematode infections (HINIs) remain a public health concern despite reduced prevalence following mass drug administration (MDA) in low- and middle-income countries. Children continue to bear a substantial burden of infection, and caregiver knowledge and practices may influence their risk of acquiring infection. Sustaining control during the transition of prevention programmes to surveillance-based strategies requires an understanding of behavioural determinants of transmission. Therefore, we assessed caregiver knowledge, attitudes, and practices (KAP) and their associations with sociodemographic characteristics and child infection status. A community-based cross-sectional study was conducted among 945 caregivers of primary school children in Anuradhapura, a low-prevalence setting where school-based MDA ceased in 2019, to assess caregiver KAP and child HINI status. An interviewer-administered questionnaire assessed KAP, sociodemographic, water, sanitation, hygiene (WASH), and behavioural factors. Participants were predominantly mothers (89.5%). Good knowledge was observed in 61.7%, positive attitudes in 95.6% and good practices in 99.2%. Knowledge gaps persisted regarding transmission and complications. Higher caregiver knowledge (OR = 0.52; 95% CI: 0.36–0.72) and regular deworming (OR = 0.58, 95% CI: 0.40–0.83) were associated with lower odds of infection, whereas attitudes and practices were not independently associated. Caregiver knowledge remains a key determinant of infection risk. Gaps in knowledge, misconceptions, and practices may sustain transmission even in low-prevalence settings. Strengthening health education, school-based hygiene promotion, and community engagement remains essential to reinforce preventive behaviours and support long-term control as countries transition from routine MDA to elimination-oriented strategies. Full article

No previous sub-Saharan studies have compared patients with community-acquired pneumonia (CAP) and COVID-19 pneumonia, the focus of this study. Consecutive adult patients hospitalized with CAP (n = 59) or COVID-19 pneumonia (n = 74) were compared regarding multiple characteristics, including cardiac biomarkers. In multivariable logistic regression analysis, differences were noted among various clinical features. Troponin I concentrations (p = 0.00028) and the Troponin I/NT-pro BNP ratio (p = 0.00048) were significantly higher in COVID-19 compared with CAP. After adjustment for age, these differences remained significant (troponin I p = 0.0019; ratio p = 0.00054), while BNP concentrations were now higher in CAP (p = 0.009). PCA demonstrated that BNP and NT-pro BNP contributed most strongly to the dominant cardiac biomarker signature, suggesting shared cardiopulmonary stress across both diseases. Exploratory subgroup analyses suggested higher troponin I levels among people living with HIV and COVID-19, although interaction modelling did not demonstrate significant effect modification by HIV status. Both CAP and COVID-19 pneumonia were associated with evidence of cardiac stress; however, COVID-19 demonstrated a relatively stronger myocardial injury signature characterized by higher troponin I concentrations and an increased Troponin I/NT-pro BNP ratio while CAP had evidence of greater hemodynamic cardiac strain, as evidenced by the higher levels of BNP. The findings suggest that the mechanisms of cardiac involvement may differ between viral and bacterial respiratory infections. Full article

Mycoplasma pneumoniae pneumonia (MPP) is a leading cause of community-acquired pneumonia in children, yet little is known about the role of nasopharyngeal microbiota dysbiosis in susceptibility to infection and disease subtype. In this study, we performed 16S rRNA sequencing on nasopharyngeal samples from 102 pediatric MPP patients, 104 influenza A patients, and 103 healthy controls and compared the microbial diversity, composition, and functional profiles across groups. The MPP group exhibits an altered nasopharyngeal microbial composition, characterized by reduced microbial diversity and an increased relative abundance of genera including Mycoplasma, Pseudomonas, Acinetobacter, and Tannerella. Distinct microbiota profiles were identified for the MPP subtypes, with Mycoplasma more abundant in bronchopneumonia (BP) than in lobar pneumonia (LP). A microbial classifier based on the relative abundance of the nasopharyngeal microbiota was established to distinguish MPP patients from both influenza patients and healthy controls, with an area under the receiver operating characteristic curves of 0.978. Key microbial features associated with MPP included Mycoplasma, Mycobacterium, Aeromonas, and Acinetobacter. In addition, PICRUSt2-based functional predictions suggested alterations in amino acid metabolism and predicted functional pathways associated with bacterial infection and antimicrobial resistance in MPP patients. In conclusion, this study provides comprehensive insights into alterations in the nasopharyngeal microbiota in pediatric MPP. These findings highlight the potential role of dysbiosis in disease progression and suggest that changes in microbiota composition and functional profiles are associated with MPP infection. Full article

Background: Infectious diseases remain a leading cause of mortality in South Africa, compounded by a high HIV prevalence. This study aimed to delineate the spectrum and clinicopathological characteristics of fatal infectious diseases through a postmortem audit to inform clinical practice and public health strategy. Methods: A retrospective, cross-sectional descriptive study was conducted on all autopsies with a final cause of death attributed to infectious disease at a National Health Laboratory Service, in Northern Pretoria, Gauteng, South Africa, from 2012 to 2021. Using the Systematised Nomenclature of Medicine Clinical Terms (SNOMED) code and word search engines codes, 55 cases were identified. Data on demographics, clinical presentation, HIV status, antiretroviral therapy (ART), comorbidities, and final autopsy diagnosis were extracted from the laboratory information system. Histological confirmation was performed using standard stains. Descriptive statistical analysis was conducted using STATA-18. Results: The cohort (n = 55) had a median age of 31 years (IQR 19–45) and was predominantly female (67%). HIV prevalence was 35%, with 68% of those on ART. The leading cause of death was multilobar pneumonia (36%), followed by bronchopneumonia (22%). AIDS-defining illnesses were present in 27% of cases, with disseminated tuberculosis being the most common (46%). Septic shock was identified in 18% of decedents. A significant proportion (60%) of the cohort was HIV-negative. Conclusions: This autopsy series reveals a high burden of fatal community-acquired pneumonias and HIV-associated opportunistic infections, with a notable proportion of deaths occurring in HIV-negative individuals. The findings underscore diagnostic gaps and highlight the critical role of autopsy in accurate mortality surveillance, advocating for enhanced antemortem diagnostic protocols and targeted public health interventions. Full article

Background: Non-pharmaceutical interventions during the COVID-19 pandemic altered respiratory pathogen circulation, and a bacterial rebound followed once restrictions were lifted. We describe pediatric pneumococcal respiratory infections and their bacterial co-detections in the immediate post-pandemic period. Methods: We retrospectively analyzed respiratory specimens from children aged 0–18 years tested with a multiplex real-time PCR panel (Allplex Respiratory Panel, Seegene, Seoul, South Korea; seven bacterial pathogens) restricted to this predefined bacterial spectrum at a tertiary pediatric hospital in Galați, Romania, during 2022 and 2023. A total of 2546 panels were performed in 2022 and 3250 in 2023, allowing pneumococcal positivity rates to be calculated. Proportions are reported with Wilson 95% confidence intervals; associations were tested with Pearson chi-square and Fisher exact tests in SPSS v.23. Results: Children with detected Streptococcus pneumoniae rose from 100 to 415, corresponding to a rise in pneumococcal positivity from 3.9% (100/2546) to 12.8% (415/3250). Among the positive children, pneumococcus–Haemophilus influenzae co-detection increased from 33.0% to 45.1% (odds ratio 1.63, 95% CI 1.02–2.61; p = 0.029), while pneumococcus alone fell from 60.0% to 50.1%. Boys, urban residence, and early childhood predominated, and community-acquired pneumonia diagnoses rose from 61 to 214. No profile–demographic association reached significance (panel–residence 2023, p = 0.063). Conclusions: A post-pandemic rise in pediatric pneumococcal detections and increasing H. influenzae co-detection were observed, supporting syndromic multiplex PCR in rapid pediatric diagnostics and antimicrobial stewardship. Full article

Streptococcus pneumoniae is a leading cause of community-acquired pneumonia, yet the immune mechanisms required for protection against invasive pulmonary infection remain inadequately understood. Using a murine model of homologous protection against invasive pneumococcal pneumonia, we explored the relative contributions of humoral and cellular immunity using adoptive serum transfer, immune cell depletion, and lung transcriptional profiling. Our findings indicated that passive transfer of immune serum provided robust protection, while neutrophil depletion significantly compromised bacterial control, highlighting that both antibodies and neutrophils are key mediators of protection. In contrast, depletion of CD4⁺ T cells or NK cells did not compromise survival. Although IL-17A has been widely implicated in host defense against pneumococcal infection, IL-17A-deficient mice remained protected, albeit with delayed clearance and reduced early antibody responses. We associate this delay with compensatory upregulation of IL-17F and increased expression of Th1-associated genes in the lungs. Together, these findings indicate that IL-17A is not essential for protection and support a model in which coordinated Th1- and Th17-related cytokine responses collectively promote neutrophil recruitment and effective antibody-mediated defense. These results highlight functional redundancy within the IL-17 cytokine axis and suggest that integrated cytokine networks, rather than individual mediators, underpin protective immunity to pneumococcal pneumonia, with implications for next-generation vaccine design. Full article

Background: Pneumonia is a common cause of hospitalization and a significant contributor to worldwide morbidity and mortality. Effective definitive antimicrobial therapy for pneumonia relies on accurate identification of bacterial pathogens and their resistance patterns. Therefore, this study aims to evaluate the distribution bacterial pathogens and their antimicrobial resistance patterns, as well as clinical factors associated with outcomes among hospitalized pneumonia patients. Methods: This retrospective cohort study was conducted at Dr. Hasan Sadikin General Hospital, Indonesia, and included adult patients hospitalized with pneumonia between January and December 2024. Clinical, demographic, microbiological, and outcome data were extracted from electronic medical records and the laboratory system. Bacterial distribution, antimicrobial patterns, and clinical outcomes were analyzed descriptively and compared across pneumonia types. Multivariable regression analyses were performed to identify factors associated with in-hospital mortality and length of hospital stay. Results: A total of 662 hospitalized pneumonia patients were included with Gram-negative bacteria (i.e., Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa) identified as the most common pathogens. Carbapenem-resistant Acinetobacter baumannii (CR-Ab) and Klebsiella pneumoniae (CR-Kp) were the most frequently identified resistant pathogens, particularly in hospital-acquired (HAP) and ventilator-associated pneumonia (VAP). HAP and VAP were independently associated with higher in-hospital mortality and longer hospital stay compared to community-acquired pneumonia (CAP). In addition, CR-Ab and difficult-to-treat Pseudomonas aeruginosa (DTR-Psa) were associated with prolonged hospitalization. Conclusions: Type of pneumonia, bacterial pathogens and resistance patterns were associated with in-hospital mortality and length of hospital stay. These findings highlight the importance of ongoing microbiological surveillance, antimicrobial stewardship, and infection prevention strategies to optimize pneumonia management and clinical outcomes. Full article

Coronary artery fistulae (CAF) are uncommon congenital or acquired coronary anomalies. A CAF occurs when a coronary artery bypasses the myocardial capillary bed to directly communicate with a cardiac chamber, a great vessel, or another vascular structure. Many CAFs are found by chance. If haemodynamically significant, a CAF may cause a variety of phenomena e.g., myocardial ischaemia, arrhythmias, heart failure, pulmonary hypertension, infective endocarditis/endarteritis, aneurysm formation, and late thrombotic complication. Management is anatomy-driven and dependent on the precise definition of the CAF’s origin, course, termination, multiplicity, associated coronary remodeling, and complications, together with an assessment of physiological relevance. Invasive coronary angiography is indispensable for real-time haemodynamics and transcatheter therapy, yet the two-dimensional projection nature can incompletely characterize complex CAF anatomy. Gated computed tomography coronary angiography (CTCA) produces high-resolution volumetric imaging with robust three-dimensional (3D) reconstruction and is central to contemporary diagnosis, quantitative risk stratification, procedural planning, and follow-up. This review examines the role of CTCA for the diagnosis and management of CAF and aims to provide a comprehensive overview for physicians managing this esoteric group of patients. Full article

Background: Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and represent a significant public health concern due to their high prevalence and increasing antimicrobial resistance. This study aimed to systematically review the epidemiology, uropathogens, and resistance patterns of UTIs in Portugal over the last decade. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines. A literature search was performed in April 2026. A total of 425 records were identified. After removal of duplicates and preliminary exclusions, 121 records were screened by title and abstract. Following application of eligibility criteria, 41 full-text articles were assessed, of which 13 met the criteria for detailed eligibility assessment. Six studies met the inclusion criteria and were included in the final qualitative synthesis. Results: The included studies consistently reported a higher prevalence of UTIs in females and, in some cases, in older populations. Escherichia coli was identified as the predominant uropathogen across all studies, followed by Klebsiella pneumoniae, Proteus spp., and Enterococcus spp. A consistently high prevalence of antimicrobial resistance was observed, particularly against commonly used antibiotics such as ampicillin and trimethoprim–sulfamethoxazole. The presence of extended-spectrum β-lactamase (ESBL)-producing strains was also reported, especially in healthcare-associated infections, which exhibited higher resistance profiles compared to community-acquired infections. Conclusions: The available evidence suggests that UTIs in Portugal are predominantly caused by enterobacteria, particularly Escherichia coli. However, the limited number and heterogeneity of studies highlight the need for cautious interpretation. Further multicenter and methodologically robust studies are required to better characterize national epidemiological patterns and antimicrobial resistance trends. Full article

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a significant pathogen for both hospital-acquired and community-acquired infections, characterized by its strong epidemic potential and high mortality rate, posing a severe threat to global public health. CRKP spreads widely across the globe through the horizontal transfer of plasmid-mediated resistance genes such as *blaKPC*, *blaNDM*, and *blaOXA-48*. The clinical treatment options for this bacterium are limited, and its resistance has been increasing year by year, urgently necessitating the development of new antimicrobial drugs or alternative strategies. In recent years, the CRISPR-Cas system has shown great potential in the diagnosis and treatment of CRKP, including rapid detection and identification, gene editing, antimicrobial strategies, and resistance inhibition. For instance, CRISPR-Cas12a/13a can be used for the rapid detection and identification of CRKP, while CRISPR-Cas9/Cas3 can target resistance genes to reverse the resistance of strains. With the advancement of delivery and biotechnologies, the CRISPR-Cas system is expected to become an important tool against drug-resistant CRKP. This review focuses on the application of the CRISPR-Cas system in the detection and treatment of CRKP, analyzing its technical advantages, limitations, and future development directions. Full article

Background/Objectives: Patients in long-term care hospitals (LTCHs) are at increased risk of harboring antimicrobial-resistant organisms due to frequent healthcare exposure and multiple comorbidities. This retrospective observational study aimed to compare the antimicrobial susceptibility of bacterial isolates from LTCH-onset infections (LTCHIs) with those from community-acquired infections (CAIs) in elderly patients. Methods: This study was conducted at a 700-bed urban tertiary university hospital and included patients aged ≥65 years with positive cultures for bacteremia, lower respiratory tract infections (LRTIs), or urinary tract infections (UTIs) within 48 h of admission. Medical records, including antimicrobial susceptibility test results, were reviewed for a total of 1780 patients and their isolates. Antimicrobial susceptibility patterns were compared between LTCHI and CAI patients. Results: Patients with LTCHI exhibited significantly higher antimicrobial non-susceptibility than those with CAIs across multiple pathogens and antimicrobial classes (p < 0.05). In bacteremia, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae from LTCHI cases showed increased non-susceptibility to β-lactams and fluoroquinolones. In LRTIs, Pseudomonas aeruginosa and Acinetobacter baumannii demonstrated high non-susceptibility to carbapenems (52.9% and 90%, respectively) and aminoglycosides. In UTIs, LTCHI isolates exhibited broader resistance among Enterobacterales and P. aeruginosa. Notably, the proportion of multidrug-resistant organisms, including carbapenem-resistant Enterobacterales (15.4–50.0%) and carbapenem-resistant Acinetobacter baumannii (90.5%), was substantially higher in the LTCHI group across all infection sites. Conclusions: Elderly patients with LTCHI are more likely to harbor antimicrobial-resistant pathogens than those with CAIs. Careful consideration of LTCHI origin is therefore essential for empirical antibiotic selection and for strategies aimed at limiting further resistance. Full article

Background: Clostridioides difficile is classified within the first 18 threats for antimicrobial resistance and is the leading cause of hospital-acquired enteric infection. Community-associated cases have notably increased in recent decades, highlighting that accurate and up-to-date statistics characterizing the epidemiology of C. difficile infection (CDI) are critical. Methods: We conducted a retrospective (2019–2023) case-control study evaluating the prevalence of CDI in 249 stool samples from hospitalized patients in the sanitary region III of Buenos Aires, Argentina. The presence of C. difficile was detected by combining EIA, PCR, and toxigenic culture via a diagnostic algorithm. Clinical and demographic data from patients were analyzed to identify CDI-associated risk factors. We also conducted a systematic review and a meta-analysis contrasting our results with 38 studies selected from different countries. Results: One in five patients presented C. difficile as the etiological agent of diarrhea. Eighty percent of the CDI+ cases carried toxigenic strains, with a third of cases associated with community environments. Age ≥ 69 years, previous use of antibiotics, previous hospitalization, and previous episodes of CDI emerged as predisposing factors for CDI in our study cohort. In an exploratory evaluation of clinical data, CDI+ patients showed higher leukocytes and platelets counts, a decreased basophil count, and increased urea concentration. At the global level, the meta-analysis reinforced advanced age, previous consumption of antibiotics, previous consumption of proton pump inhibitors, previous hospitalization, and previous CDI as risk factors for CDI. Conclusions: These results emphasize the importance of continued epidemiological surveillance of CDI. Our findings confirm previously described risk factors, both in our cohort and at the global level. Exploratory alterations in laboratory parameters were observed, although their clinical relevance and specificity require further investigation. Full article