Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is a potentially life-threatening infection that can affect humans and a wide variety of animals in the tropics. In December 2017, a swine melioidosis case was discovered during a meat inspection at a privately-owned slaughterhouse in Nakhon Si Thammarat Province in southern Thailand. The infection, which continued for several months, caused a dispute about where the disease began. An environmental investigation into two farms—both involved in raising the first infected pig—ensued. Through genetic analysis, the investigation revealed that a contaminated water supply at one farm was the probable source of infection. The three local sequence types identified in the investigation were types 51, 298 and 392.

Burkholderia pseudomallei is a Gram-negative bacterium and the causative agent of melioidosis in humans and animals in the tropics. The clinical manifestations of melioidosis are diverse, ranging from localized infections to whole-body sepsis. The effective serological method is crucial for the point-of-care diagnosis of melioidosis. The aim of this study was to develop indirect immunofluorescence assay (IFA)-based methods for detecting immunoglobulin G (IgG) antibodies in melioidosis patients. These methods use whole-cell antigens made from recombinant E. coli strains that express major B. pseudomallei antigens, including TssM, OmpH, AhpC, BimA, and Hcp1. A total of 271 serum samples from culture-confirmed melioidosis patients (n = 81), patients with other known infections (n = 70), and healthy donors (n = 120) were tested. Our study showed that the recombinant TssM strain had the highest performance, with 92.6% sensitivity, 100% specificity, 100% positive predictive value, 96.9% negative predictive value, 97.8% efficiency, 97.0% accuracy, and no cross-reactivity. The method agreement analysis based on k efficiency calculations showed that all five IFA methods perfectly agreed with the standard culturing method, while the traditional indirect hemagglutination (IHA) method moderately agreed with the culture. In summary, our investigations showed that the TssM-IFA method could be used for melioidosis diagnosis.

Background: The early diagnosis of pulmonary tuberculosis (PTB) remains a global challenge. While serum adenosine deaminase (ADA) has been associated with tuberculosis-related immune activation, its consistency across different regions and laboratory methods remains unclear. This study aims to evaluate group-level differences in serum ADA levels and identify factors influencing these variations. Methods: A systematic search was conducted across PubMed, Embase, and Scopus up to February 2026. A meta-analysis using a random-effects model was performed to calculate the pooled standardized mean difference (SMD), reflecting group-level differences in serum ADA levels between PTB patients and control groups. Results: Thirty-four studies were included. Serum ADA levels were significantly higher in PTB patients compared to healthy controls (SMD = 3.15, 95% CI: [2.51–3.79], p < 0.0001) and other respiratory diseases (SMD = 2.06, 95% CI: [1.38–2.74], p < 0.0001). Subgroup analyses revealed that geographical region and ADA measurement methods did not significantly account for the observed high heterogeneity (I² > 95%), indicating that ADA elevation was consistently observed across studies. Conclusions: Serum ADA levels were significantly elevated in patients with PTB, indicating a consistent biological association with disease status. However, given the high heterogeneity and the absence of diagnostic accuracy measures (e.g., sensitivity and specificity), these findings should not be interpreted as evidence of clinical diagnostic performance. Further diagnostic test accuracy studies are required to establish its clinical utility.

Background and Aim: Escherichia coli O157:H7 is enterohemorrhagic E. coli, which produces verocytotoxin or Shiga toxin. It is a well-known cause of severe diseases in humans worldwide. Cattle and other ruminants are the main reservoirs of this organism. Sports animals, such as fighting bulls, riding horses, and fighting cocks, are economic animals in Southern Thailand. This study aimed to identify E. coli O157:H7 from the rectal swabs of these sports animals and determine the antimicrobial susceptibility patterns of isolated bacteria. Materials and Methods: The rectal swabs were collected from 34 fighting bulls, 32 riding horses, and 31 fighting cocks. The swabs were cultured on MacConkey (MAC) Agar; the suspected colonies were then identified by VITEK® 2 GN card, and the antimicrobial susceptibility was tested by VITEK® 2 AST N194 in VITEK® 2 Compact automation. Escherichia coli O157:H7 was confirmed by culturing on sorbitol MAC agar, the ability to grow at 44°C, and the presence of H7 antigen. In addition, the eaeA (E. coli attaching and effacing), along with stx1 and stx2 (Shiga cytotoxins) genes, were determined using polymerase chain reaction. Finally, the cytotoxicity of Shiga toxin was confirmed using the Vero cytotoxicity test. Results: Fifty-five suspected isolates (56.70%), which were collected from 19 fighting bulls (55.88%), 13 riding horses (40.63%), and 23 fighting cocks (71.13%), were identified as E. coli. However, one sample (Bull H9/1) from fighting bulls had an equal confidence level (50%) for E. coli and E. coli O157. The confirmation of this isolate demonstrated that it was sorbitol non-fermenter, could assimilate L-lactate, was unable to grow well at 44°C, and reacted with anti-serum to H7 antigen. In addition, it was positive with stx2 and eaeA genes, and the toxin affected Vero cells by a dose-dependent response. The antimicrobial susceptibility test revealed that five out of 55 (9.09%) E. coli isolates were resistant to antimicrobial agents. All five isolates (21.74%) were collected from fighting cocks. Escherichia coli Cock H4/3 was only one of the five isolates resistant to three antimicrobial agents (ciprofloxacin, moxifloxacin, and trimethoprim/sulfamethoxazole). Fortunately, it was not multidrug-resistant bacteria. Conclusion: This is the first report on detection of E. coli O157:H7 in fighting bulls and antibiotic-resistant characteristic of E. coli in fighting cocks in Southern Thailand. This research is beneficial in preventing the dissemination of E. coli O157:H7 or antimicrobial agent-resistant E. coli in sports animals and humans.

Background: Burkholderia pseudomallei, the causative agent of melioidosis, infects diverse animal species and reflects environmental contamination. However, the global seroprevalence of B. pseudomallei in animals remains incompletely characterized. Methods: A systematic review and meta-analysis were conducted according to PRISMA guidelines and registered in PROSPERO (CRD420261306404). PubMed, Embase, and Scopus were searched for observational studies reporting seroprevalence of B. pseudomallei in animals. Random-effects meta-analysis was performed to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses were conducted by animal group, geographic region, diagnostic method, and indirect hemagglutination assay (IHA) cut-off value. Risk of bias was assessed using the Joanna Briggs Institute checklist. Results: Twenty studies involving 78,914 animals were included. The pooled seroprevalence of B. pseudomallei was 11% (95% CI: 6–19%), with substantial heterogeneity (I² = 98.1%, p < 0.0001). Wildlife showed the highest prevalence (16%; 95% CI: 10–25%), followed by livestock (11%; 95% CI: 6–19%). Significant geographic variation was observed (p < 0.0001), with higher prevalence reported in North America (18%) and Southeast Asia (10%). Seroprevalence estimates varied according to diagnostic method and IHA cut-off values. Sensitivity analyses yielded similar pooled prevalence estimates after exclusion of small studies, supporting the stability of the overall findings despite persistent heterogeneity. Conclusions: Exposure to B. pseudomallei is widespread among animal populations and influenced by geographic and methodological factors. Standardized diagnostic approaches and expanded animal surveillance are needed to improve understanding of melioidosis epidemiology within a One Health framework.

Background: Pediatric melioidosis causes substantial morbidity and mortality in tropical regions, yet its clinical spectrum has not been comprehensively quantified. We conducted a systematic review and meta-analysis to characterize clinical manifestations, organ involvement, and mortality among children with melioidosis. Methods: PubMed, Embase, and Scopus were searched from inception to 31 May 2026 for observational studies reporting clinical manifestations or outcomes in children (<18 years) with melioidosis. Pooled prevalence estimates and case-fatality rates were calculated using random-effects generalized linear mixed models with logit transformation. Heterogeneity was assessed using Cochran’s Q, I², and τ². Country subgroup analyses were performed, and small-study effects were assessed for outcomes with at least ten studies. Results: Twenty-five studies involving 6874 children from 10 countries were included. Localized infection predominated (69%; 95% CI, 52–82%), whereas disseminated infection occurred in 30% (95% CI, 18–46%). Skin and soft tissue infection was the most frequent manifestation (31%; 95% CI, 23–41%), followed by lymphadenitis (24%; 95% CI, 3–76%), pneumonia (18%; 95% CI, 17–19%), and parotitis (13%; 95% CI, 5–28%). Bacteremia occurred in 23% (95% CI, 11–43%), septic shock in 6% (95% CI, 0–53%), and the pooled case-fatality rate was 12% (95% CI, 7–20%). Significant geographic variation was observed for localized infection, disseminated infection, pneumonia, bacteremia, and mortality (all p < 0.01). Small-study effects were detected for several outcomes. Conclusions: Pediatric melioidosis predominantly presents as localized disease, but disseminated infection, bacteremia, and mortality remain clinically important. Geographic variation and substantial heterogeneity highlight differences in disease presentation across settings. These findings provide quantitative evidence to support earlier recognition, diagnostic evaluation, and timely management of pediatric melioidosis in endemic regions.