Early Access

Nontuberculous mycobacteria (NTM) are an ecologically diverse group of environmental mycobacteria that are increasingly recognized as an important cause of human and animal disease. While most infections arise from environmental exposure, evidence from outbreak reports and genomic epidemiology suggests animal- associated and device-associated transmission pathways that intersect with human occupational and clinical risk. This review synthesizes current knowledge on zoonotic and animal-associated NTM, including recent taxonomy updates driven by genomic approaches, major reservoirs (including aquaculture, livestock, wildlife, and engineered water systems), as well as clinical and veterinary manifestations, and operational laboratory approaches for detection and characterization. We present a tiered diagnostic framework, ranging from microscopy and culture to targeted polymerase chain reaction (PCR), whole-genome sequencing, and emerging metagenomic and artificial intelligence (AI)-based pipelines, and we discuss biosafety considerations, reporting standards, and One Health surveillance priorities. Key research gaps include distinguishing true animal-to-human transmission from shared-source exposure, harmonizing One Health metadata and antimicrobial resistance (AMR) surveillance, and validating climate-sensitive predictive models. We propose practical, resource-adaptive recommendations for surveillance, laboratory workflows, and outbreak response. A coordinated global investment in integrated One Health genomic surveillance, harmonized metadata standards, and capacity building is urgently required to detect, attribute, and mitigate zoonotic NTM threats.

Keywords: Nontuberculous mycobacteria, zoonosis, One Health, molecular diagnostics, whole-genome sequencing, antimicrobial resistance

Objective: This study aimed to evaluate the diagnostic performance of the combination disk method and carbapenem inactivation method (CIM) for detecting carbapenemase production in Enterobacterales isolates with reduced susceptibility or resistance to carbapenems, using real-time multiplex polymerase chain reaction (PCR) as the reference method.

Materials and Methods: Enterobacterales isolates obtained from clinical samples between 2015 and 2016, which were at least minimally susceptible or resistant to at least one carbapenem, were included in the study. Phenotypic evaluation was performed using the KPC&MBL&OXA-48 combination disk kit (Liofilchem, Italy), which detects Klebsiella pneumoniae carbapenemase (KPC), metallo-β-lactamase (MBL), and OXA-48-type carbapenemases.  In addition, the CIM method was applied. For genotypic confirmation, the KPC, OXA-48, and New Delhi metallo-β-lactamase (NDM) genes were investigated using the BD MAX^TM CRE Assay (Becton, Dickinson and Company, Sparks, MD, USA).  Diagnostic accuracy parameters and the agreement coefficient (κ) were calculated for the index tests.

Results: A total of 111 Enterobacterales isolates were analyzed. The majority of isolates were K. pneumoniae (n=80; 72.1%) and Escherichia coli (n=20; 18.0%). Carbapenemase genes were detected in 90 isolates by real-time multiplex PCR. The OXA-48 gene predominated (68.5%), while OXA-48+NDM (9.9%) and NDM (2.7%) were also detected; KPC was not detected.  The sensitivity and specificity of the temocillin resistance-based phenotypic approach for predicting the presence of OXA-48 or OXA-48+NDM were 100.0% and 95.8%, respectively (κ=0.97). The MBL phenotype of isolates carrying NDM showed complete agreement with multiplex PCR for carbapenemase detection using the CIM test (sensitivity and specificity 100%, κ=1.00).

Conclusion: The carbapenem inactivation method demonstrated high diagnostic accuracy for detecting carbapenemase production. The combination disk method, including temocillin resistance and ethylenediaminetetraacetic acid (EDTA)-based evaluation, showed strong performance in predicting OXA-48- and NDM-associated carbapenemases. However, in endemic regions, phenotypic results should ideally be confirmed by molecular methods.

 Keywords: Enterobacterales, carbapenemase, OXA-48, NDM, real-time multiplex PCR, combination disk method

Objective: Nontuberculous mycobacteria (NTM) are emerging opportunistic pathogens with an increasing global incidence. However, epidemiological data and treatment outcomes remain limited in Türkiye. This study aimed to evaluate the clinical characteristics, species distribution, and treatment outcomes of NTM infections in a tertiary center in Türkiye.

Materials and Methods: A retrospective analysis was conducted of patients diagnosed with NTM infection between 2021 and 2025 in the Department of Infectious Diseases and Clinical Microbiology. The diagnosis was established according to the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) criteria. Demographic characteristics, risk factors, radiological findings, microbiological profiles, antimicrobial susceptibility patterns, treatment regimens, and clinical outcomes were analyzed.

Results: Fourteen patients were included in the study. The mean age was 50.1 ± 13.8 years, and nine patients were male. Underlying risk factors were present in eight patients, including human immunodeficiency virus (HIV) infection (n = 4), malignancy (n = 3), bronchiectasis (n = 1), and chronic obstructive pulmonary disease (COPD) (n = 1). The most frequently identified species were Mycobacterium kansasii (n = 5) and Mycobacterium abscessus (n = 5), followed by Mycobacterium avium, Mycobacterium simiae, Mycobacterium gordonae, and Mycobacterium lentiflavum (n = 1 each). Pulmonary involvement was observed in 10 patients, with nodular lesions in nine and bronchiectasis in five. Among isolates with available antimicrobial susceptibility results (n = 13), susceptibility to clarithromycin, moxifloxacin, linezolid, and amikacin was observed in 12 isolates, whereas resistance was most frequently detected to ciprofloxacin (n = 10) and trimethoprim-sulfamethoxazole (n = 9). Of the 12 patients who initiated treatment, complete clinical response was achieved in nine and partial response in one; two patients with malignancy died before treatment initiation.

Conclusion: M. kansasii and M. abscessus were the most frequently identified NTM species in this cohort. Favorable treatment outcomes were observed when therapy was guided by antimicrobial susceptibility results. Species-level identification and susceptibility testing are essential for optimal disease management and strengthening diagnostic capacity.

 Keywords: Nontuberculous mycobacteria, Mycobacterium kansasii, Mycobacterium abscessus, antimicrobial susceptibility, pulmonary infection, HIV

Objective: This study aimed to evaluate seroprotection rates after a standard three-dose hepatitis B vaccination series in adults with immune-mediated rheumatic diseases (IMRDs) and to identify clinical and treatment-related factors associated with vaccine response in routine clinical practice.

Materials and Methods: This retrospective observational study was conducted between January 2022 and August 2024. Adults with rheumatologist-confirmed IMRDs who were susceptible to hepatitis B virus (HBV) at baseline and who underwent quantitative hepatitis B surface antibody (anti-HBs) testing 4–8 weeks after receipt of the third vaccine dose were included.

Results: Of 260 eligible patients, 161 completed the standard three-dose hepatitis B vaccination series, and post-vaccination anti-HBs results were available for 152 patients included in the final analysis. Seroprotection was achieved in 110 (72.4%) patients. In multivariable logistic regression analysis, longer disease duration and systemic corticosteroid exposure were independently associated with lower odds of achieving seroprotection. Age, sex, smoking status, body mass index, and comorbidity burden were not independently associated with vaccine response.

Conclusion: In adults with IMRDs, approximately three-quarters achieved seroprotection after standard hepatitis B vaccination. Longer disease duration and systemic corticosteroid exposure were independently associated with reduced serologic response. These findings highlight the importance of timely vaccination and consideration of cumulative immunosuppressive burden in routine clinical practice.

Keywords: Hepatitis B vaccines, rheumatic diseases, immunosuppression, glucocorticoids, seroprotection

Objective: This scoping review aimed to characterize antimicrobial stewardship (AMS) interventions in transplant recipients, compare antibacterial, antifungal, and antiviral stewardship strategies, summarize clinical and economic outcomes, and identify knowledge gaps relevant to health policy.

Materials and Methods: The study was conducted according to the Joanna Briggs Institute methodology and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. Original research articles published between January 2015, and March 2025 were identified through searches of the PubMed, Scopus, and Web of Science databases. Data were synthesized using thematic analysis.

Results: Fifteen studies published between 2017 and 2025 were included. Thematic analysis categorized the interventions into the following domains: intervention structure, individualized strategies, diagnostic management, clinical and economic outcomes, comparative findings by population and transplant type, and implementation barriers. All studies included an antibacterial stewardship component (100%), whereas antifungal (20%) and antiviral (7%) interventions were comparatively limited. Interventions were primarily implemented as guideline-based optimization and prospective audit-and-feedback models. Infectious disease specialists participated in 87% of the studies, while clinical pharmacists were involved 33%. Clinical effects were predominantly reported using process indicators. A reduction in antimicrobial treatment duration (47%) and improved guideline adherence (33%) were the most frequently reported outcomes. Studies evaluating mortality and graft survival were limited (27%), and most did not demonstrate significant differences. Economic outcomes were reported in 73% of the studies, with program-level cost reductions ranging from 20% to 40%. The most common implementation barriers were high resource requirements and heterogeneity of guidelines.

Conclusion: Antimicrobial stewardship practices in transplant recipients are primarily focused on antibacterial management and are associated with improvements in short-term process indicators. However, evidence regarding long-term clinical outcomes and antifungal and antiviral stewardship practices remains limited. Developing transplant-specific, multidisciplinary, and sustainable AMS models is essential for antimicrobial resistance control and patient safety in this high-risk population.

Keywords: Antimicrobial stewardship, transplantation, scoping review, health policy

Objective: This study aimed to examine the distribution of theses on healthcare-associated infections (HAIs) in Türkiye, determine the publication rates of these theses in peer-reviewed scientific journals, and identify strategies to increase publication rates.

Materials and Methods: Theses on HAIs completed between 2000 and 2023 were screened in the YÖKTEZ (National Thesis Center) database. For each thesis, the title, the author’s specialty, academic degree, and year of completion were recorded. The included theses were subsequently searched across national and international databases to determine their publication status. For each identified publication, the article title, journal name, year of publication, and indexing status were documented.

Results: A total of 1077 theses were included in the study. Of these, 34.2% were conducted in Medical Microbiology and 26.1% in Infectious Diseases and Clinical Microbiology. Overall, 40.1% (n = 432) of the theses were converted into scientific publications. Among the published studies, 41.4% (n = 179) were indexed in Science Citation Index (SCI), Science Citation Index Expanded (SCI-E), or Emerging Sources Citation Index (ESCI). No statistically significant difference in publication rates was observed between disciplines (p = 0.7).

Conclusion: Although a substantial number of theses on HAIs have been conducted in Türkiye, the rate of conversion into academic publications remains lower than expected. Increasing awareness of this issue and developing solution-oriented strategies may improve scientific productivity and publication output in this field.

Keywords: Healthcare-associated infections, medical theses, publication rate, bibliometric analysis, postgraduate education

Objective: This study aimed to evaluate the diagnostic potential of serum microRNA-21 (miR-21) as a noninvasive biomarker for active pulmonary tuberculosis (PTB) and to compare its performance with conventional diagnostic methods, including smear microscopy and the GeneXpert MTB/RIF assay.

Materials and Methods: A cross-sectional study was conducted between July 2024 and August 2025 in Duhok and Mosul, Iraq. Sputum samples were examined by Ziehl-Neelsen (ZN) staining, and selected samples were analyzed using the GeneXpert MTB/RIF assay. Serum samples were collected from patients with confirmed active PTB and healthy controls. Serum miR-21 expression levels were quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR), normalized to U6 small nuclear RNA as an internal reference, and analyzed using the comparative Ct (2⁻ΔΔCt) method. Statistical analysis was performed using SPSS software, and a p-value of ≤ 0.05 was considered statistically significant.

Results: A total of 474 sputum samples collected from 40 patients and 30 healthy controls were examined. Serum miR-21 expression was significantly higher in patients with PTB compared with healthy controls (9.29 ± 0.11 vs. 1.30 ± 0.02; p = 0.0001), corresponding to an approximately 6.6-fold increase. In addition, ZN smear microscopy detected acid-fast bacilli in 35 samples (7.3%). GeneXpert confirmed Mycobacterium tuberculosis in 31 of 150 samples (20.7%), including 10 smear-negative cases, and identified rifampicin resistance in 3 (9.7%) cases.

Conclusion: Serum miR-21 was significantly upregulated in patients with active PTB, suggesting its potential as a noninvasive biomarker that may complement existing diagnostic methods. However, large-scale studies are needed to further validate its diagnostic value.

Keywords: Pulmonary tuberculosis, GeneXpert MTB/RIF, Ziehl-Neelsen staining, microRNA-21, RT-qPCR, biomarker

Mycoplasma pneumoniae infections cause upper and lower respiratory tract infections across all age groups and may also present with extrapulmonary involvement in addition to respiratory tract disease. Mycoplasma pneumoniae-induced rash and mucositis (MIRM) are rare but crucial to recognize. It is characterized by prominent but infrequent vesiculobullous and/or target-like eruptions and mucositis. This case report presents a 30-year-old patient with M. pneumoniae pneumonia who presented with a rash and mucositis, without any comorbidities.

Keywords: Mycoplasma pneumoniae, pneumonia, rash, mucositis.

Lupus vulgaris (LV), a common form of cutaneous tuberculosis (TB), is rarely encountered in children. The disease follows a chronic course and often mimics other dermatological conditions, posing a diagnostic challenge and leading to inappropriate management. We report a rare case of a three-year-old boy who presented with a chronic ulcerated facial lesion persisting for the past two years. Skin biopsy revealed granulomatous inflammation with Langhans giant cells. A comprehensive TB workup was performed along with an evaluation to exclude other differential diagnoses. Despite negative acid-fast bacilli (AFB) staining, the diagnosis was established based on clinical features and histopathological findings. The patient responded well to standard antituberculosis therapy. On follow-up, the lesion had largely resolved without complications. This case highlights the importance of early recognition and treatment of LV, especially in TB-endemic regions, to prevent permanent disfigurement.

Keywords: Pediatric lupus vulgaris, cutaneous tuberculosis, erythematous lesion

Objective: Granulomatous mastitis (GM) is a chronic inflammatory breast disease with heterogeneous clinical presentation and uncertain optimal management. Increasing evidence suggests a role for Corynebacterium species, particularly Corynebacterium kroppenstedtii, in its pathogenesis. To evaluate the clinical characteristics, treatment strategies, and outcomes of granulomatous mastitis, with particular emphasis on cases associated with Corynebacterium species and the impact of antibiotic therapy.

Materials and Methods: This retrospective cohort study included 165 female GM patients treated at a university hospital between January 2018 and January 2023. Patients were grouped according to Corynebacterium isolation (25 positive, 140 negative). Clinical characteristics, microbiological findings, and treatment modalities—oral steroids, combined antibiotic–steroid therapy, antibiotics with intralesional steroids, and segmental mastectomy—were evaluated. The impact of lipophilic antibiotics (tetracyclines, linezolid, rifampicin) combined with steroids was assessed. Recurrence rates and associated factors, including symptom duration, were analyzed using Chi-square, Fisher’s exact, Student’s t-test, or Mann–Whitney U test.

Results: Corynebacterium spp. were detected in 15.15% of cases, with C. kroppenstedtii identified in 8.48%. Patients with Corynebacterium-associated GM had more extensive abscess formation and required more interventional procedures. Multimodal treatment strategies combining steroids, antibiotics, and surgery resulted in favorable outcomes. Lipophilic antibiotics combined with steroids showed a positive but statistically nonsignificant effect. Recurrence occurred in 16.3% of patients and was associated with longer symptom duration.

Conclusion: Accurate microbiological identification is essential in GM, particularly in C. kroppenstedtii infections, to guide targeted antibiotic therapy and reduce recurrence. Tailored management strategies, including lipophilic antibiotics, may improve outcomes. Further studies are needed to define optimal treatment duration and the role of surgery in refractory GM.

Key-words: Granulomatous mastitis, Corynebacterium kroppenstedtii, breast abscess, Corynebacterium infections, anti-bacterial agents

Objective: Contaminated environmental surfaces contribute to transmission of pathogens that cause healthcare-associated infections. The present study aimed to assess the efficacy and analyze the cost of a chlorine-based combined detergent-disinfectant applied for environmental decontamination around methicillin-resistant Staphylococcus aureus (MRSA) patients.

Materials and Methods: The study was conducted in the inpatient wards (medical, surgical and orthopaedic) of Infectious Disease Control Training Centre, the Hong Kong Special Administrative Region of the People’s Republic of China over six months. The surrounding areas of newly diagnosed MRSA patients were divided into two equal halves, and decontaminated either by the conventional two-step process (cleaning with detergent followed by disinfection with 1,000 ppm hypochlorite solution), or by a new one-step method using a combined detergent-disinfectant. High-touch areas of patient’s surroundings were sampled to detect MRSA by culture and measure adenosine triphosphate (ATP) levels before and after decontamination. The number of disposable wipes used and the duration of the decontamination process were recorded for cost analysis.

Results: Both the conventional and new methods significantly reduced MRSA detection rate from 68.7% to 12.7% and 15.3% respectively (p<0.001), and significantly reduced ATP failure rate from 78.2% to 2.7% and 4.5% respectively (p<0.001). Compared with the conventional method, the new method saved an average of 5.9 minutes of decontamination time and 10.2 pieces of disposable wipes per patient, resulting in a substantial cost saving of over 6 million Hong Kong dollars per year in total according to currently recommended infection control practices for MRSA patients in public hospitals in Hong Kong.

Conclusion: The one-step method using a combined detergent-disinfectant effectively decontaminated high-touch hospital surfaces of patient environment while reducing time and costs. Its wider adoption in local inpatient settings can be considered to enhance environmental hygiene at a lower cost.

 Keywords: Decontamination, Methicillin-Resistant Staphylococcus aureus, detergents, disinfectants, costs and cost analysis

Objective: Surgical antimicrobial prophylaxis (SAP) is a key strategy for preventing surgical site infections (SSIs), yet its implementation in clinical practice remains variable despite established guideline recommendations. This study aimed to assess neurosurgeons’ knowledge and practices regarding SAP in Türkiye and to evaluate their adherence to current guideline recommendations.

Materials and Methods: This multicenter, cross-sectional study was conducted among actively practicing neurosurgeons across Türkiye using an online survey. A structured questionnaire, informed by relevant national and international guideline recommendations, collected data on demographic characteristics and key aspects of SAP, including antibiotic selection, timing of initiation, dosing strategies, and duration of prophylaxis. Categorical variables were analyzed using the chi-square test, and a p-value <0.05 was considered statistically significant.

Results: A total of 464 participants were included. Overall, 28.7% of respondents rated their SAP knowledge as “good,” ranging from 21.9% among residents to 80% among professors (p<0.001). Guideline-concordant antibiotic selection was reported by 70.7% of participants; however, in cranial procedures, ceftriaxone was preferred over cefazolin in 56.2% of cases. Adherence to recommended timing of prophylaxis initiation was reported by 62% of participants, while 68.1% administered additional intraoperative doses during prolonged surgeries. Only 51.7% considered patient body weight when adjusting doses, and 37.9% reported discontinuing prophylaxis within 24 hours postoperatively. Professors demonstrated higher adherence across several parameters, including initiation timing, dosing, and discontinuation (all p<0.05).

Conclusion: Adherence to key components of SAP remains suboptimal among neurosurgeons in Türkiye. Although knowledge levels varied across academic ranks, this did not consistently translate into clinical practice. Structured educational initiatives, institutional protocols, and audit-based interventions may help improve adherence to guideline-recommended SAP practices.

Keywords: Surgical antimicrobial prophylaxis, neurosurgery, guideline adherence; cross-sectional survey

The integration of immune checkpoint inhibitor therapy in the field of medical oncology has shifted prognosis of multiple solid organ malignancies, though, such an advancement is not without significant adverse events referred as immune-related adverse events. A novel pattern of autoimmune-like hepatitis following certain medication exposures including statins, isoniazid, nitrofurantoin, anti-tumor necrosis factor-alpha therapy and minocycline has recently been defined. We hereby present a 66-year-old male patient with extensive-stage small-cell lung carcinoma (SCLC) who was inflicted by acute liver injury while undergoing a conjunction of atezolizumab therapy and isoniazid prophylaxis for latent tuberculosis. The patient subsequently developed hepatotoxicity which improved after a discontinuation of isoniazid therapy and administration of corticosteroids. The aim of this report is to contribute to the literature by presenting a rare case of grade IV immune-related hepatotoxicity under atezolizumab therapy in a patient receiving isoniazid prophylaxis for latent tuberculosis.

Keywords: Atezolizumab, small-cell lung cancer, immune-related hepatotoxicity.

Ventriculitis is a severe CNS infection with high mortality. We present a 24-year-old male with nasopharyngeal carcinoma who developed Klebsiella pneumoniae ventriculitis during hospitalization. Symptoms included fever, headache, and altered mental status. Due to acute hydrocephalus, an external ventricular drain (EVD) was inserted; purulent CSF subsequently grew K. pneumoniae. Despite aggressive intravenous and intrathecal antibiotic therapy, the patient died from septic shock. This case highlights the rapid clinical deterioration associated with Gram-negative bacterial ventriculitis and the management difficulties in immunosuppressed oncological patients, emphasizing the critical nature of this rare but fatal complication.

Keywords: Nasopharyngeal carcinoma, Klebsiella pneumoniae, ventriculitis, cerebrospinal fluid, hydrocephalus

Pasteurella multocida, a Gram-negative coccobacillus commonly found in the oropharyngeal flora of cats, is a rare cause of peritoneal dialysis–associated peritonitis. We report a 44-year-old patient with exposure to stray cats who presented with abdominal pain and cloudy dialysis effluent. Laboratory tests revealed leukocytosis and elevated CRP, and empirical intraperitoneal cefazolin was started. Peritoneal fluid culture yielded P. multocida, resistant to fluoroquinolones, but susceptible to penicillin, cefotaxime, trimethoprim-sulfamethoxazole, and tetracycline. The patient showed rapid clinical improvement. This case highlights the need to assess animal exposure in PD patients and underscores emerging resistance patterns within a One Health approach.

 Keywords: Pasteurella multocida, peritoneal dialysis, peritonitis