Early Access

Objective: Although HIV RNA can be suppressed with antiretroviral therapy (ART), chronic inflammation may persist in people living with HIV (PLWH). Because a low CD4/CD8 ratio is associated with morbidity and mortality, this study aimed to evaluate factors associated with CD4/CD8 ratio normalization, defined as achieving CD4/CD8 ≥1.

Materials and Methods: This retrospective cohort study included PLWH aged ≥18 years who were diagnosed between 2010 and 2017 and achieved viral suppression within the first year after starting ART. Data were retrospectively obtained from a tertiary infectious diseases clinic.

Results: Among 217 patients followed for five years, 187 (86.2%) achieved CD4⁺ >500 cells/μL and 87 (40.1%) reached a CD4/CD8 ≥1. In multivariable logistic regression, higher baseline CD4⁺ T-cell count and baseline CD4⁺/CD8⁺ ratio were independently associated with CD4/CD8 ratio normalization.

Conclusion: Including immunological markers alongside viral suppression may better reflect treatment success. Baseline immunological status appears to be associated with long-term CD4/CD8 ratio normalization in PLWH receiving suppressive ART. Monitoring these markers may help inform long-term follow-up strategies.

Keywords: CD4-CD8 ratio, HIV, viral suppression, immune reconstitution, chronic inflammation, antiretroviral therapy (ART)

Objective: Staphylococcus aureus is a leading cause of community-acquired skin and soft tissue infections (SSTIs), for which empirical oral therapy is frequently initiated in outpatient practice. Ongoing shifts in antimicrobial resistance may compromise the reliability of commonly prescribed non–β-lactam agents. This study evaluated six-year trends in methicillin resistance and susceptibility to widely used non–β-lactam oral antibiotics among outpatient-derived S. aureus isolates.

Materials and Methods: In this retrospective observational study, non-duplicate S. aureus isolates recovered from wound, abscess, and tissue specimens of outpatients between January 2020 and December 2025 were analyzed. Identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing and methicillin resistance screening (cefoxitin) were conducted in accordance with EUCAST criteria. Resistance to clindamycin, tetracycline, trimethoprim–sulfamethoxazole (TMP-SMX), and inducible clindamycin resistance (iMLSB phenotype) were assessed. Temporal trends were analyzed statistically.

Results: A total of 1,890 isolates were included, of which 655 (34.6%) were methicillin-resistant (MRSA). The proportion of MRSA increased significantly over time, reaching 39.0% in 2025. Significant upward trends were observed for clindamycin, inducible clindamycin, and tetracycline resistance (all p for trend ≤0.004). In contrast, TMP-SMX resistance remained consistently low (<5%) without a significant increase. MRSA isolates demonstrated markedly higher resistance rates than methicillin-susceptible strains. Adults exhibited higher resistance to methicillin and tetracycline than children.

Conclusion: Rising MRSA prevalence and declining activity of clindamycin and tetracycline may limit empirical oral treatment options for outpatient SSTIs. TMP-SMX retained stable in vitro activity. Continuous outpatient-focused surveillance is essential to support evidence-based empirical therapy.

Keywords: Staphylococcus aureus, MRSA, skin and soft tissue infections, outpatient surveillance, antimicrobial resistance

Objective: This study aimed to investigate the differences in HIV/AIDS knowledge and attitudes across medical students at distinct academic stages, evaluating their relation to a structured Infectious Diseases and Clinical Microbiology (IDCM) clerkship and sociodemographic characteristics.

Materials and Methods: This research was conducted as a cross-sectional and comparative study from 1 March 2024 to 5 July 2024. The medical students were divided into three cohorts: third-year (preclerkship), fourth-year (postclerkship), and fifth-year (postclerkship, advanced-stage) students. This study does not follow the same individuals over time but compares different cohorts at distinct educational stages.

Results: The study included 291 medical students (median age 22; 51.9% male). Among fourth-year students, the IDCM clerkship significantly increased median knowledge scores from 19 (9–21) to 20 (13–21) and attitude scores from 54 (26–85) to 57 (17–85). Knowledge scores were 18 (9–21) for third-year, 20 (13–21) for fourth-year (posttest), and 19 (12–21) for fifth-year students; attitude scores were 51 (22–80), 57 (17–85), and 55 (19–76), respectively. Knowledge and attitude scores were significantly higher in the post-clerkship fourth-year cohort than in the third-year cohort. Knowledge increased in fifth-year vs third-year students, though attitude differences were non-significant. IDCM clerkship independently predicted higher knowledge. Female gender, the clerkship, and paternal education predicted positive attitudes.

Conclusion: HIV/AIDS knowledge scores were significantly higher among cohorts who had completed the IDCM clerkship; however, attitudinal differences across cohorts were less prominent. These findings suggest that while higher educational stages are associated with higher cognitive scores, differences in professional attitudes may require more integrated, long-term educational strategies across the curriculum.

Keywords: HIV/AIDS, medical education, stigma, socio-demographic factors

Objective: Invasive non-typhoidal Salmonella (iNTS) infection may cause severe systemic and focal disease, particularly in patients with comorbidities or immunosuppression. Data on the clinical features and antimicrobial resistance patterns of iNTS infections in Türkiye remain limited. We evaluated the clinical and microbiological characteristics of adult patients with microbiologically confirmed iNTS infection.

Materials and Methods: This retrospective single-center case series included adult patients diagnosed with iNTS infection at a tertiary-care hospital in Türkiye between 2015 and 2025. iNTS infection was defined as isolation of non-typhoidal Salmonella from blood or other sterile body sites. Clinical, microbiological, antimicrobial susceptibility, and outcome data were analyzed.

Results: Nine patients with iNTS infection were identified. The median age was 54 years (IQR: 45–68), and five patients (55.6%) were male. Underlying comorbidities were present in eight patients (88.9%), most commonly hypertension, diabetes mellitus, autoimmune diseases, and HIV infection. Gastrointestinal symptoms were observed in only two patients (22.2%), whereas seven patients (77.8%) presented without typical enteric manifestations. Bacteremia was detected in seven patients (77.8%), and focal invasive infections were identified in five patients (55.6%), including spondylodiscitis, septic arthritis, thyroid abscess, and liver abscess. Salmonella enterica serovar Enteritidis was the predominant serovar, identified in six isolates (66.7%), while three isolates (33.3%) were classified as Salmonella enterica subsp. enterica without further serovar determination. All isolates remained susceptible to third-generation cephalosporins, whereas resistance to ampicillin and ciprofloxacin was detected in four (44.4%) and three isolates (33.3%), respectively. The median length of hospitalization was 16 days, and two patients (22.2%) died during follow-up.

Conclusion: iNTS infection may present with heterogeneous and frequently non-enteric manifestations, particularly in adults with significant comorbidities or immunosuppression. The high frequency of focal invasive disease and elevated ciprofloxacin resistance in this series highlight the importance of early microbiological diagnosis, evaluation for metastatic infectious foci, and appropriate empirical antimicrobial therapy.

Keywords: Invasive non-typhoidal Salmonella, bacteremia, focal infection, antimicrobial resistance, case series

Objective: Galectin-3 (Gal-3) is a galactose-binding lectin released from immune cells that affects immune response and plays a role in type 2 diabetes mellitus (DM) and related vascular complications. This study aimed to investigate the relationship between Gal-3 levels and infection/inflammation processes among patients with type 2 DM, diabetic foot infection (DFI), and healthy volunteers.

Materials and Methods: Thirty-six DFI patients, 24 Type 2 DM patients without signs of infection, and 24 healthy volunteers with no comorbidities admitted to our clinic were included in the study. Serum Gal-3 levels were measured using ELISA. Data were analyzed using SPSS version 21. Statistical significance was set at p<0.05 for all tests.

Results: The median Gal-3 level was determined as 232.54 pg/mL in the patient group with DFI, 209.14 pg/mL in the type 2 DM group, and 277.85 pg/mL in the healthy group. No statistically significant difference in Gal-3 levels was found among the three groups (p>0.05). Sixteen (44.4%) of the patients with DFI were classified as PEDIS 4, 11 (30.6%) as PEDIS 3, and 9 (25%) as PEDIS 2. When the relationship between DFI severity and Gal-3 levels was evaluated, there was no statistically significant difference in Gal-3 levels across PEDIS staging (p>0.05). There were no statistically significant differences between Gal-3 levels and C-reactive protein, procalcitonin, leukocyte count, or erythrocyte sedimentation rate values ​​(p>0.05).

Conclusion: In our study, no significant increase in Gal-3 levels was determined in patients with DFI and type 2 DM compared to the healthy population. More comprehensive studies on this topic are required.

Keywords: Biomarker, diabetic foot infection, galectin-3, PEDIS, diabetes mellitus

Objective:  We examined 11-year trends in resistance and resistant microorganism isolation rates per 1,000 patient-days of key Gram-positive  and Gram-negative bacteria in a Turkish tertiary-care hospital.

Materials and Methods: Microbiology data were obtained from the first isolate per patient per admission between January 2014 and December 2024. Organisms were identified by VITEK MS/MALDI-TOF, antimicrobial susceptibility was determined by VITEK2 or BD Phoenix (disk diffusion for selected agents), applying CLSI breakpoints throughout and EUCAST from 2015 onward. Resistance rates (%) and resistant organism isolation rates per 1,000 patient-days were calculated.

Results: Enterococcus faecalis remained highly susceptible throughout the study period. In contrast, Enterococcus faecium showed progressive increases in ampicillin and vancomycin resistance, with ampicillin-resistant bloodstream isolation rates approximately doubling from 0.405 in 2014 to 0.773 in 2023. Methicillin-resistant Staphylococcus aureus isolation rates rose sharply over the same period, from 0.230 in 2014 to 0.945 in 2022 in the non-bloodstream. Carbapenem resistance of Acinetobacter baumannii remained persistently high but broadly stable, except for a notable spike in 2021. Resistance rates and isolation rates per 1,000 patient-days of K. pneumoniae to carbapenems (29% to 62% in 2023 in bloodstream) and third-generation cephalosporins (50% to 74% in bloodstream) were found to be increasing, with the emergence of ceftazidime–avibactam resistance. Third-generation cephalosporin resistance in Escherichia coli increased initially, but subsequently stabilized, while carbapenem resistance rates and carbapenem-resistant E. coli isolation rates remained low and stable. Pseudomonas aeruginosa showed increasing resistance trends with year-to-year fluctuations.

Conclusion: The resistance exhibited divergent trends: E. faecium, S. aureus, K. pneumoniae, E. coli, P. aeruginosa had rising resistance rates and resistant bacteria isolation rate, while E. faecalis, A. baumannii, were relatively stable. Resistance rates serve as an indicator for updating local empiric therapy guidelines. Isolation rates represent a primary outcome measure for effectiveness of infection prevention and control programs.

Keywords: Enterococcus faecalis, E. faecium, Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, antibacterial resistance rate, multi-drug resistance, carbapenem resistance, vancomycin resistance, Extended spectrum beta-lactamase, ESBL, Türkiye

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

Crimean–Congo hemorrhagic fever (CCHF) is a life-threatening viral infection that may mimic HELLP syndrome during pregnancy. We describe a 30-year-old woman at 23 weeks’ gestation presenting with fever, myalgia, thrombocytopenia, and severe transaminase elevation. Initial suspicion of HELLP syndrome was reconsidered due to high fever, rural exposure, and rapidly progressive coagulopathy. CCHF was confirmed by polymerase chain reaction. Despite intensive supportive therapy and plasma exchange, fulminant multiorgan failure developed, resulting in simultaneous maternal and fetal death. This case underscores the need to consider CCHF in febrile pregnant patients with thrombocytopenia in endemic areas.

Keywords: Crimean-Congo hemorrhagic fever, pregnancy, HELLP syndrome, thrombocytopenia, maternal and fetal mortality, differential diagnosis

The recent Andes virus (ANDV) cluster associated with the MV Hondius adventure cruise ship has renewed global concern regarding the pandemic potential of hantaviruses. We reviewed the available evidence for human-to-human transmission of ANDV, focusing on major outbreaks in Argentina and Chile and the ongoing cruise-associated cluster. Although epidemiologic and molecular investigations suggest that limited person-to-person transmission may occur following prolonged close contact, important methodological limitations, including shared environmental exposure, long incubation periods, recall bias, and uncertainty in transmission chain reconstruction, complicate interpretation. Notably, despite theoretically favorable conditions for transmission aboard the cruise ship, only 13 (12 confirmed, 1 probable) cases were identified among 147 passengers and crew members. Current evidence therefore supports limited human-to-human transmission under specific epidemiologic circumstances but does not indicate that ANDV is a readily transmissible pandemic-prone respiratory virus. Rigorous epidemiologic investigation remains essential to accurately characterize transmission dynamics during future outbreaks.

Keywords: Andes virus, hantavirus, human-to-human transmission, cruise ship outbreak

Artificial Intelligence (AI) is increasingly influencing healthcare, with growing relevance in infectious diseases and clinical microbiology This review summarizes current applications of machine learning (ML), deep learning (DL), and large language models (LLMs) in these areas while critically evaluating their strengths and limitations. Although AI has demonstrated promising performance in image analysis, molecular diagnostics, risk prediction, and clinical decision support, its routine implementation remains constrained by limited external validation, heterogeneous datasets, algorithmic bias, and challenges related to generalizability and explainability. The review also discusses the emerging role of AI in scientific writing and the ethical and practical considerations associated with its clinical adoption. Overall, current evidence suggests that AI should be regarded as a complementary decision-support technology whose safe and effective integration depends on rigorous validation, high-quality data, and appropriate clinical oversight.

Keywords: Artificial Intelligence, machine learning, deep learning, clinical microbiology, infectious diseases, diagnostics, clinical decision support, antimicrobial stewardship, prognostic models, medical parasitology, large language models

Ochrobactrum species are aerobic, non-fermenting Gram-negative bacilli that are increasingly recognized as causes of healthcare-associated infections. Among them, Ochrobactrum intermedium remains a rare human pathogen and poses therapeutic challenges due to its resistance to multiple antimicrobial agents. We report a case of hospital-acquired sepsis caused by O. intermedium bacteremia in an 82-year-old woman with advanced pancreatic cancer. Clinical resolution was achieved following removal of the central venous catheter and a seven-day course of intravenous meropenem. This case underscores the role of O. intermedium as an emerging opportunistic pathogen in immunocompromised patients.

Keywords: Bacteremia, Ochrobactrum intermedium, catheter-related bloodstream infection, healthcare-associated infection

Gardnerella vaginalis (G. vaginalis) pneumonia in men is very rare, with most reported cases occurring in critically ill patients with major predisposing conditions. We describe a man in his 60s with poorly controlled diabetes mellitus who developed G. vaginalis pneumonia complicated by septic shock after an influenza-like illness in the setting of household influenza exposure. He required mechanical ventilation, and G. vaginalis was isolated from both sputum and blood cultures. Empirical meropenem, vancomycin, and azithromycin were de-escalated to intravenous ampicillin according to susceptibility testing, followed by oral clindamycin, for a total treatment duration of 6 weeks. Despite the absence of trauma, prolonged mechanical ventilation before onset, or a clear aspiration event, he developed severe pneumonia with lung abscess formation and achieved full clinical and radiographic recovery.

Keywords: Gardnerella vaginalis, pneumonia, septic shock

The clinical presentation of ocular cat-scratch disease (CSD) is heterogeneous. Here, we report a case of CSD with atypical ocular manifestations to enhance clinical awareness of this condition. A 6-year-old girl presented with decreased visual acuity in the left eye. Ophthalmic examination revealed extensive exudative retinal detachment, a large yellow-white granulomatous lesion in the posterior retina. The diagnosis of ocular CSD was subsequently confirmed by metagenomic sequencing. The patient received intravenous azithromycin and oral rifampicin, along with intravitreal injections of conbercept and ceftazidime. Retinal reattachment was observed within 3 weeks. This case highlights atypical clinical manifestations of ocular CSD.

Keywords: Cat-scratch disease, extensive serous retinal detachment, bartonella henselae

Anaphylactic shock associated with hydatid cysts is rare but potentially fatal usually occurrs following cyst rupture. We report the case of a 23-year-old man who developed sudden anaphylaxis without evidence of cyst rupture. Imaging demonstrated hepatic hydatid cysts, and the diagnosis was supported by a positive indirect hemagglutination test. After successful stabilization, surgical treatment was planned. During surgery, a second anaphylactic episode occurred despite no visible rupture. The cysts were excised completely, and surgical and histopathological findings confirmed hepatic hydatid disease. Albendazole therapy was initiated postoperatively. This case underscores that hydatid disease should be considered in patients with unexplained anaphylaxis, particularly in endemic regions, even in the absence of apparent cyst rupture.

Keywords: Hydatid cyst, anaphylaxis, liver, echinococcus, spontaneous

Plasmodium falciparum is the most virulent malaria species, associated with life-threatening complications. We report a 25-year-old male returning from an endemic region presenting with fatigue, nausea, and diarrhea initially diagnosed as viral gastroenteritis. One day later, he developed headache and clinical deterioration requiring readmission. Although meningitis and encephalitis were considered due to neurological symptoms and travel history, peripheral blood smear revealed P. falciparum gametocytes, confirming the diagnosis. Antimalarial therapy was initiated promptly. This case highlights the importance of travel history and considering malaria in atypical presentations

Keywords: Cerebral malaria, plasmodium falciparum, imported malaria, post-artesunate delayed hemolysis, travel medicine