Nontuberculous mycobacterial pulmonary disease in low-risk patients is rare and typically indolent. We report a case of Mycobacterium abscessus complex (MABC) pulmonary disease in a 71-year-old immunocompetent Italian man who presented with mild dyspnoea that markedly worsened following SARS-CoV-2 infection three months before admission. High-resolution CT showed diffuse small, irregular, predominantly consolidative opacities with peripheral bronchial thickening. Extensive investigations for tuberculosis, fungal infection, other pathogens, and malignancy were negative. Respiratory cultures subsequently yielded MABC, and molecular testing identified a functional erm(41) gene conferring inducible macrolide resistance, consistent with M. abscessus subsp. abscessus. Guideline-based multidrug therapy with intravenous amikacin, tedizolid, clofazimine, and moxifloxacin was initiated. Nephrotoxicity required substitution of intravenous amikacin with an inhaled formulation, followed by ototoxicity and further modification with tigecycline. Despite these adjustments, cultures remained persistently positive. Severe gastrointestinal intolerance and progressive weight loss ultimately led to treatment discontinuation and home oxygen therapy. One year after diagnosis, imaging revealed new cavitary lesions with advanced bilateral disease. The patient died from respiratory failure and severe cachexia. This case shows that MABC infection may follow an aggressive, life-threatening course even in immunocompetent individuals. Antimicrobial resistance combined with treatment-limiting toxicity underscores the urgent need for more effective, better-tolerated therapies and early multidisciplinary management.

The objective of this study was to investigate whether Candida albicans infection may contribute to the development of the carious process. This study included six adult patients, three with oral C. albicans infection and three healthy subjects (Candida-negative). All participants exhibited moderate dental caries intensity, determined by the result based on DMFT index. Simultaneously, the activity of dental caries did not differ between the subjects. In addition, the accumulation of dental plaque assessed using the Plaque Index (Pl.I) was moderate in all individuals. Salivary glucose and pH values did not differ between the subjects. The results suggest that the influence of chronic Candida infection on the development of dental caries is uncertain.

We evaluated in vitro activity of thymol in combination with β-lactams, gentamicin, or colistin against Carbapenem-Resistant Acinetobacter baumannii (CRAb) and KPC-producing Klebsiella pneumoniae (KPC-Kp) clinical isolates displaying different susceptibility profiles. Thymol, when combined with β-lactams, did not exert synergistic interactions, whereas in association with colistin it showed additive or synergistic activity against 85.7% (6/7) and 14.3% (1/7) of MDR-GNB clinical isolates, respectively. These results showed that thymol in association with colistin may be considered a potential strategy that warrants further investigation as a potential antimicrobial-adjuvant strategy for patients colonized by MDR-GNB clinical isolates, also hypothesizing the ability to reduce the spread of emerging resistance traits.

With its rising incidence, dengue is a growing global health concern. This retrospective observational study evaluated short-term safety of the dengue vaccine TAK-003 in people with asymptomatic HIV infection and no evidence of impaired immune function that have received at least one dose of TAK-003 at the Travel Medicine Clinic of the Infectious Diseases Unit of San Raffaele Scientific Institute, Milan, Italy, from January 2024 to December 2025. Globally, 12/20 (60%) participants did not report any adverse event after both doses. Seven (35%) experienced mild general or local disorders after dose 1, one reported local disorders after D2. In each case, adverse events resolved spontaneously after 1-3 days. No severe AEs were reported. HIVRNA, CD4+ count and percentage did not significantly vary after both doses of TAK-003. TAK-003 was well tolerated, with adverse events being generally mild, self-limiting and comparable to those observed in the general population. Individuals of ≥60 years of age did not report any adverse events. No significant changes in HIVRNA, CD4+ count and percentage were observed after vaccination.

Current recommendations for screening Chlamydia trachomatis (CT) and Neisseria gonorrhoeae in urinary tract infections using nucleic acid amplification tests (NAATs) include vaginal swabs for women and first‑catch urine for men. In addition, some manufacturers require the use of a transport medium for prolonged pre‑analytical storage. The aim of this study was to evaluate the sensitivity and specificity of midstream urine specimens and to assess nucleic acid stability in neat urine samples stored at +4°C. The study included 338 asymptomatic participants undergoing screening for Chlamydia trachomatis and Neisseria gonorrhoeae as part of the French national STI screening program (172 women and 166 men). For each participant, a reference specimen (self‑collected vaginal swab for women and first‑catch urine for men) was compared with a midstream urine sample. Two comparisons were conducted to assess nucleic acid stability: the first compared urine stored in a preservation medium with neat urine stored at +4°C, and the second compared neat urine stored at +4°C on days 1 and 7. All samples were analysed using the Alinity m Abbott® automated system with the STI AMP Kit. Among the 46 positive samples, the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was 43/338 and 4/338, respectively. Due to the low prevalence of NG, sensitivity and specificity analyses for midstream urine were limited to CT. Vaginal swabs showed superior performance for detecting CT in females, with two infections missed by midstream urine. Midstream urine demonstrated adequate sensitivity in females (92.9%) and excellent sensitivity in males (100%), with no false-positive results observed. Regarding nucleic acid stability, no statistical difference (p=0.799) was observed for cycle values between urine samples eluted into the liquid medium and neat urine stored at +4°C. Furthermore, our study validated the use of prolonged storage periods (up to 7 days) at +4°C for CT and NG detection in neat urine (p=0.671). In conclusion, the results of this study corroborate the CDC's 2014 recommendations, but the use of midstream urine could offer interesting prospects for Chlamydia trachomatis screening in specific populations. Regarding Neisseria gonorrhoeae, given the low prevalence of positive results found in our study, no meaningful conclusions can be drawn.

Dermatophytes are the leading cause of cutaneous fungal infection worldwide, followed by non-dermatophyte molds and Candida spp. Microbiological diagnosis is essential to identify the etiological agent and to guide targeted therapy. Conventional methods, including direct microscopy and fungal culture, are fundamental tools in the diagnostic workflow. This study aimed to assess quantitative Multiplex Tandem PCR performance in comparison with microscopy and culture for rapid and accurate identification in real clinical practice. A total of 50 clinical specimens were collected and analyzed with conventional methods. Direct microscopic examination yielded positive results in 45 out of 50 samples (90%), while fungal culture identified clinically significant fungi in 29 out of 50 cases (58%). The same 50 specimens were retrospectively analyzed using Multiplex MT-PCR, which detects major dermatophytes, Scopulariopsis, Aspergillus and Candida species. MT-PCR identified fungal DNA in 84% of samples. Compared to standard reference methods, the assay demonstrated a sensitivity of 84% and a specificity of 60%. Notably, MT-PCR identified fungal pathogens that were missed by conventional techniques in 32% of cases, significantly reducing the turnaround time. Conversely, 6% of samples were PCR-negative but culture-positive, likely reflecting pre-analytical variability and sample heterogeneity. Although the sample size was limited, MT-PCR proved to be a rapid and highly sensitive complementary diagnostic tool, warranting further investigation in larger-scale studies.

Infections caused by multidrug-resistant Gram-negative bacteria, particularly carbapenemase-producing Enterobacterales, present significant diagnostic and therapeutic challenges, highlighting the need for practical laboratory methods to evaluate combination therapies. This study investigated 90 ceftazidime-avibactam (CZA)-resistant Klebsiella pneumoniae isolates collected from clinical specimens between January 2021 and July 2023. Species identification was performed using MALDI-TOF MS, and antimicrobial susceptibility testing was conducted with the BD Phoenix™ system according to Clinical and Laboratory Standards Institute (CLSI) criteria, with disk diffusion used for confirmation when necessary. Carbapenemase production was determined phenotypically using the modified Carbapenem Inactivation Method. For a subset of isolates with available whole-genome sequencing data, resistance genes were confirmed, although genotypic analysis was not performed for all isolates. The in vitro activity of the CZA plus aztreonam (CZA-ATM) combination was evaluated using the CLSI-recommended broth disk elution method. All isolates were resistant to CZA and aztreonam when tested individually, whereas no visible growth was observed with the combination, indicating in vitro susceptibility. These findings suggest that the broth disk elution method is a practical approach for assessing CZA-ATM activity in routine clinical laboratories. Further studies including reference method validation and evaluation of borderline or resistant isolates are needed.

Mutations in the pncA gene of Mycobacterium tuberculosis, which encodes the PZase enzyme, are closely linked to pyrazinamide (PZA) resistance. Two clinical isolates, R1 and R2, which are resistant to pyrazinamide at concentrations of 100 μg/mL and 150 μg/mL, respectively, harbor multiple pncA mutations. The pncA R1 gene carries T41C, G419A, and A535G, causing Cys14Arg, Arg140His, and Ser179Gly substitutions in PZase; the pncA R2 gene has G76T, G112C, A403C, and G419A, resulting in Ala26Ser, Ala38Pro, Thr135Pro, and Arg140His changes. The relationship between the biochemical characteristics of the enzymes with pyrazinamide resistance in isolates R1 and R2 remains unclear. This paper presents the catalytic kinetics of mutant enzymes and explores their association with PZA resistance. The impact of these mutations on enzyme function was evaluated by expressing recombinant PZase in Escherichia coli, resulting in the production of proteins approximately 21 kDa in size, as confirmed by SDS-PAGE analysis. Kinetic analysis revealed reduced catalytic efficiency (kcat/KM) for the PZase-R1 and PZase-R2 variants, measured at 1.759 mM¯[1]·min¯[1] and 1.500 mM¯[1]·min¯[1], respectively, in comparison to the wild-type enzyme, which exhibited a value of 2.443 mM¯[1]·min¯[1]. These reductions correspond to decreases of 28.0% for PZase-R1 and 38.6% for PZase-R2. The observed declines in catalytic efficiency are likely to contribute to the development of resistance to pyrazinamide (PZA). Further studies, including site-directed mutagenesis and structural modelling, are needed to clarify the impact of each mutation on PZase function and drug interaction.

Patients on maintenance hemodialysis (HD) face a high risk of severe infections, though global incidence estimates for sepsis and bloodstream infections (BSIs) are lacking. We performed a systematic review and meta-analysis following PRISMA guidelines, searching databases (1990-2025) for studies reporting these incidence rates. Pooled rates were calculated using a random-effects model. From 49 included studies (over 1.7 million patients across 21 countries), the pooled incidence rate of sepsis or BSI was 136.75 episodes per 1,000 person-years (95% CI 88.88-210.41) and 1.98 episodes per 1,000 catheter-days (95% CI 1.22-3.23). Substantial heterogeneity (I[2] >98%) was observed. Incidence varied markedly by WHO region, with the highest rate in South America (3,600 per 1,000 person-years) and the lowest in the Western Pacific (78.54). BSI incidence (150.29 per 1,000 person-years) was higher than sepsis (102.90). Studies published after 2010 reported lower incidence than earlier studies, suggesting a potential temporal decline. Sepsis and BSIs remain major complications for HD patients globally, with a high and heterogeneous burden. The findings underscore the urgent need for standardized definitions, enhanced infection prevention strategies-particularly reducing central venous catheter dependence-and targeted interventions in high-burden regions to mitigate this significant clinical and economic burden.

Viral respiratory tract infections, particularly Human Bocavirus (HBoV) infections, are a significant global health concern. COVID-19 has provided a suitable platform for infectious diseases caused by multiple pathogens. This review highlights key aspects of the current status and future prospects of HBoV research in the Kingdom of Saudi Arabia, including global and local prevalence, clinical impact, and diagnostic challenges. It also emphasizes the need for future research, particularly in Saudi Arabia, to fill knowledge gaps, improve diagnosis, and design and develop future treatment and prevention strategies. HBoV was identified from a ten-year-old infected patient in Sweden from collected nasopharyngeal samples in 2005. It has been classified into four genotypes (1-4), and HBoV-1 causes respiratory infections requiring hospitalization. Co-infections with other viruses are well known, with the most common symptoms being pneumonia, cough, fever, and wheezing. Most studies on HBoV diagnosis have relied primarily on polymerase chain reaction techniques. Even though pediatric HBoV infections are common worldwide, due to limited HBoV research, there is a lack of awareness among healthcare providers, especially in Saudi Arabia and the Middle East & North Africa region. Expanding research and awareness on HBoV is urgently required to address the burden of respiratory infections in these regions, not only to explore long-term effects, potential treatments, and vaccine development, but also to use advanced diagnostic methods to analyze the changing epidemiology of respiratory pathogens and achieve effective infection control measures.

Acute cholangitis is a potentially life-threatening condition commonly caused by bacterial infections of the biliary tract. Here, we present an unusual case of acute cholangitis caused by Vibrio cholerae in a 76-year-old man with a history of hypertension, diabetes, asthma, and post-cholecystectomy who presented with upper abdominal pain, jaundice, and fatigue. Lab results showed elevated inflammatory markers and bilirubin. Imaging revealed gallstones and bile duct dilation. Blood cultures isolated non-toxigenic Vibrio cholerae, which was highly susceptible to all tested antibiotics. The patient was successfully treated with piperacillin/tazobactam and levofloxacin, along with supportive care. His symptoms resolved, and subsequent cultures were negative. This case highlights a rare instance of non-cholera Vibrio cholerae causing acute cholangitis and bacteremia in an elderly patient.

Peritoneal dialysis (PD) is a well-established renal replacement therapy for patients with end-stage renal disease, but peritonitis continues to represent a significant clinical challenge. While most cases are attributed to gram-positive bacteria from the skin microbiota, emerging reports have documented infections with atypical organisms, including Kocuria species. Here we present the case of a 68-year-old woman with autosomal dominant polycystic kidney disease on peritoneal dialysis who developed recurrent peritonitis episodes due to Kocuria rhizophila, a microorganism traditionally considered a non-pathogenic commensal. Despite initial resolution following intraperitoneal vancomycin therapy, the patient experienced multiple relapses within short intervals, raising concerns regarding biofilm formation and antibiotic resistance. This report highlights the diagnostic complexities, therapeutic uncertainties, and the need for accurate microbiological identification in managing uncommon pathogens. It also underscores the importance of tailored strategies and vigilant monitoring in recurrent PD-related peritonitis.

Venous thrombosis triggered by infection (immunothrombosis) is increasingly recognized during viral infections, but it can also occur in bacterial and parasitic infections. Reports of systemic thromboembolism during acute toxoplasmosis are exceptional, usually linked to pre-existing risk factors. We describe two adults with multisite venous thrombosis later diagnosed with primary Toxoplasma gondii infection. The first case was a healthy adult with fever and pulmonary embolism and splanchnic thrombosis. Serology indicated a primary T. gondii infection, and T. gondii DNA was detected in a lymph node showing Piringer-Kuchinka lymphadenitis. The second case involved an immunocompromised adult with fever, seizures, cerebral infarction, cerebral venous sinus and jugular thrombosis, and splanchnic thrombosis. T. gondii serology confirmed recent infection, and Toxoplasma DNA was retrieved in blood. Anticoagulation therapy was administered to both, with specific treatment initiated in the second case due to multi-organ involvement and an impaired immune state. Our findings provide new insights into the association between venous thromboembolism and acute toxoplasmosis and support adding T. gondii testing for febrile patients with unexplained venous thrombosis.

We present a comparison of the mucosal microbiota within different diverticula in a patient with diverticular disease (DD) complicated by diverticulitis and pelvic abscess. The conventional culture method and the 16S rRNA-based sequencing approach were employed to characterize the microbiota of perforated diverticulum (PD) and adjacent visually intact diverticulum (ID) from the same surgically resected colonic segment. Compared to PD, the microbiota of ID demonstrated depletion in butyrate-producing genera and increased abundances of Proteobacteria, Enterobacteriaceae, and Bacteroides. The predominantly pro-inflammatory character of the microbiota in ID suggests its probable pathological role in the progression of DD towards more complicated forms, up to inflammatory destruction (perforation) of the diverticulum wall. The insights of this study pave the way for the development of forthcoming clinical trials focusing on microbiota-related therapies, including the use of antibiotics, probiotics, and fecal microbiota transplantation (FMT), to potentially treat or manage DD and its complications.