Melioidosis: Burkholderia pseudomallei technical challenges in identification and susceptibility testing in a non-endemic area.

Clinical Isolates Identification of Burkholderia Species and Evaluate Their Antibiogram at a Tertiary Care Hospital

Background: The genus Burkholderia, which was previously believed to be a soil saprophyte, is now gaining attention as a human disease. Pathogenic species include B. pseudomallei, B. cepacia, B. mallei, B. gladioli, and B. thailandensis. Ongoing studies on Bukholderia have led to the isolation of more recent subspecies from human samples. The purpose of this study is to assess the antibiogram of the clinical isolates and determine the prevalence of Burkholderia spp. Methods: Demographic data and a variety of patient clinical samples were analyzed. All specimens were processed using recognized microbiological techniques. Results: Of the 8230 culture-positive samples, 1902 (23.11%) included Non-Fermenting Gram Negative Bacilli (NFGNB). It was discovered that 60 (3.2%) of these NFGNB were Burkholderia spp. Furthermore, it was found that 24 (40%) and 36 (60%) were B. pseudomallei and B. cepacia complex, respectively. Of the patients, 76.7% were over 40, and 80% were men. Diabetes mellitus was the primary risk factor (60%), and fever was the most common manifestation (53.3%). Imipenam had the lowest sensitivity, while Minocycline and Cotrimoxazole had the highest, according to antibiotic sensitivity testing. Conclusion: This study provides baseline data on the present Burkholderia infection situation at our hospital. An ongoing investigation will be useful in identifying several cases because this organism is extremely underreported.

Melioidosis: A Review and Update for the Special Operations Provider.

Melioidosis, caused by the gram-negative bacillus Burkholderia pseudomallei - a Tier 1 Select Biological agent - remains a significant cause of severe community-acquired infection in tropical regions, but with recent expanding recognition in temperate climates, including the United States. Pulmonary involvement is the most frequent clinical manifestation, ranging from subclinical nodules to fulminant necrotizing pneumonia and acute respiratory distress syndrome. Despite its clinical severity, melioidosis remains underdiagnosed due to its radiologic mimicry of tuberculosis, broad clinical manifestations, and limited laboratory capacity in many endemic areas. Special Operations Forces (SOF) participating in field exercises or operations in B. pseudomallei endemic countries are at significantly increased risk of infection. Accordingly, SOF medical providers should maintain a high index of suspicion for melioidosis and be familiar with its clinical recognition, diagnosis, and management.

Characterization of blaNDM-1 and blaOXA-23-Type Carbapenemases in Acinetobacter baumannii Isolated from Post-Surgical Patients

Background: Acinetobacter baumannii is an important opportunistic pathogen responsible for healthcare-associated infections, particularly among critically ill, intensive care unit (ICU), and post-surgical patients. The emergence of carbapenem-resistant A. baumannii (CRAB) has become a major therapeutic challenge worldwide because of its multidrug-resistant nature and limited treatment options. Despite the increasing prevalence of CRAB in Pakistan, information regarding the molecular characterization of carbapenem resistance genes among isolates recovered from surgical site infections (SSIs) remains limited. Methods: A cross-sectional study was conducted from November 2023 to February 2024 at Khalifa Gul Nawaz Hospital, Bannu, Khyber Pakhtunkhwa, Pakistan. A total of (n = 118) surgical wound specimens were collected from patients with clinically diagnosed SSIs. A. baumannii isolates were identified using standard biochemical tests and confirmed by 16S rRNA gene sequencing. In vitro antimicrobial susceptibility was determined by Kirby–Bauer disk diffusion according to CLSI 2024 guidelines. In addition, the concentration-dependent inhibition-zone response of imipenem and meropenem against carbapenem-resistant isolates was evaluated using an agar well diffusion assay. Molecular detection of blaNDM-1 and blaOXA-23 was performed by polymerase chain reaction (PCR), and representative amplicons were subjected to Sanger sequencing for further analysis. Results: In the current study, the total number of (n = 118) wound specimens from healthcare-associated patients were processed, in which A. baumannii-positive isolates (n = 23, 19.5%) were documented. Its prevalence was higher in males (69.6%) compared to females, and was strongly associated (78.2%) with elderly patients (aged 51–68 years). In vitro susceptibility testing revealed that 91.3% of isolates harbored multidrug-resistant (MDR) attributes. Antimicrobial susceptibility profiling revealed high levels of multidrug resistance, with 82.6% of isolates resistant to imipenem and meropenem, as well as 100% resistance to aztreonam and gentamicin. Colistin showed the highest activity, with 87.0% of isolates remaining susceptible. In the agar well diffusion assay, measurable inhibition of the carbapenem-resistant isolates by imipenem and meropenem occurred only at higher concentrations. Molecular screening of resistance genes identified blaOXA-23 in 60.9% and blaNDM-1 in 30.4% of isolates. Co-expression of both genes was detected in some (n = 4) isolates. Among the selected MDR isolates included in the gene resistance analysis, imipenem and meropenem resistance were recorded in 9/14 blaOXA-23-positive isolates and 5/7 blaNDM-1-positive isolates. Conclusions: This study substantiates an escalated incidence of carbapenem-resistant, MDR A. baumannii in post-surgical infections. blaOXA-23 were documented as the predominant carbapenemase gene, with co-expression of blaNDM-1 in a substantial proportion of isolates. These findings provide an important phenotypic and molecular characterization of selected carbapenemase genes in healthcare-associated infections, highlighting the exigency for strengthened antimicrobial stewardship and infection control strategies in the hospitals of the region.

Melioidosis on Phu Quoc Island, Vietnam: a retrospective case series from a remote tropical setting

Melioidosis, caused by Burkholderia pseudomallei , is an important but frequently under-recognized cause of severe infection in tropical regions, including Vietnam. Although cases have been reported from several parts of the country, published clinical data from remote island settings remain scarce. To our knowledge, no clinical case series of melioidosis from Phu Quoc Island has been previously reported. This study describes the clinical presentations, underlying comorbidities, management, and outcomes of patients diagnosed with melioidosis at a tertiary hospital on Phu Quoc Island, Vietnam. We retrospectively reviewed all patients with culture-confirmed melioidosis admitted to Vinmec Phu Quoc General Hospital between July 2022 and February 2026. Archived isolates underwent molecular confirmation using a TTS1-targeted quantitative polymerase chain reaction (qPCR) assay, followed by recA gene sequencing. Nine patients were included. Clinical, laboratory, microbiological, radiological, treatment, and outcome data were extracted from medical records. Pneumonia was the predominant manifestation, occurring in seven patients, and eight patients presented with bacteremic disease. Diabetes mellitus was the most common underlying condition (7/9), followed by chronic liver disease and previous tuberculosis. Most patients were admitted with sepsis, including four cases complicated by septic shock. Two patients developed rapidly progressive pulmonary melioidosis with acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS) and died despite intensive antimicrobial and supportive therapy, including one previously healthy individual. The remaining seven patients survived. TTS1 qPCR confirmed all available isolates, while recA sequencing demonstrated the presence of at least two closely related sequence variants among circulating isolates. Antimicrobial susceptibility testing by broth microdilution showed preserved susceptibility to amoxicillin/clavulanic acid, ceftazidime, imipenem, and trimethoprim/sulfamethoxazole in all tested isolates. This report represents, to our knowledge, the first published clinical case series of melioidosis from Phu Quoc Island. The findings highlight the broad clinical spectrum of melioidosis and its potential for rapid progression to life-threatening pneumonia, septic shock, and multiorgan failure. Clinicians should maintain a high index of suspicion in patients presenting with severe pneumonia or sepsis, particularly during the rainy season and among individuals with diabetes mellitus or chronic liver disease. Strengthening conventional microbiological capacity, including timely blood culture, accurate organism identification, and standardized antimicrobial susceptibility testing, remains essential for improving diagnosis and patient outcomes in geographically isolated settings.

A Case Series of Melioidosis: The great imitator in MAPIMS hospital, Melmaruvathur, Tamil Nadu, India

Blastocystis species in hepatic abscesses: innocent bystander or hidden culprit? A case report and literature review

Abstract Blastocystis hominis is a ubiquitous intestinal parasite commonly detected in human stools. Queries about the pathogenic nature of B. hominis in immunocompetent individuals have been raised with conflicting reports about the clinical significance of detecting the parasites in various specimens. Reports have documented invasive intestinal infections and the detection of Blastocystis species in both a splenic cyst and a hepatic abscess. We present the case of a 65-year-old man with a history of recent travel to a tropical country who was found to have multiple hepatic abscesses. Analysis of the hepatic abscess fluid confirmed the presence of Entamoeba histolytica and Blastocystis species, and, to our knowledge, this is the second reported case of the same findings. Overall, the clinical and microbiological picture was most consistent with amoebic liver abscess secondary to E. histolytica; however, the presence of Blastocystis species introduces uncertainty around its clinical significance. Further studies are required to investigate the pathogenicity of Blastocystis species, including molecular investigations into the various genetic subtypes.