METHODS: We reviewed 39 cases of splenic abscesses in a district hospital in Kapit, Sarawak, from January 2017 to December 2018. The demographics, clinical characteristics, underlying diseases, causative organisms, therapeutic methods, and mortality rates were investigated.
RESULTS: There were 21 males and 18 females (mean age, 33.7±2.7 years). Almost all patients (97.4%) had a history of pyrexia. Diabetes mellitus was present in 8 patients (20.5%). Splenic abscesses were diagnosed using ultrasonography and were multiple in all 39 cases. Positive blood cultures were obtained in 20 patients (51.3%), and all yielded B. pseudomallei. Melioidosis serology was positive in 9 of 19 patients (47.4%) with negative blood cultures. All patients were treated for melioidosis with antibiotics without the need for surgical intervention. All splenic abscesses resolved after anti-melioidosis treatment was completed. One patient died (2.6%) as a result of B. pseudomallei septicaemia with multiorgan failure.
CONCLUSIONS: Ultrasonography is a valuable tool for diagnosing splenic abscesses in resource-limited settings. B. pseudomallei was the most common etiological agent of splenic abscesses in our study.
METHODS: We conducted a retrospective descriptive study of all children aged
PRINCIPAL FINDINGS: We performed whole genome sequencing and RT-qPCR analysis on the strains isolated during this study to gain further insights into their differences. We thus identified two types of resistance mechanisms in these clinical strains. The first one was an adaptive and transient mechanism that disappeared during the course of laboratory sub-cultures; the second was a mutation in the efflux pump regulator amrR, associated with the overexpression of the related transporter.
CONCLUSION: The development of such mechanisms may have a clinical impact on antibiotic treatment. Indeed, their transient nature could lead to an undiagnosed resistance. Efflux overexpression due to mutation leads to an important multiple resistance, reducing the effectiveness of antibiotics during treatment.
METHODOLOGY/PRINCIPLE FINDINGS: Here we report on the distribution of B. pseudomallei sequence types (STs) in Malaysia and how the STs are related to STs globally. We obtained 84 culture-confirmed B. pseudomallei from confirmed septicaemic melioidosis patients from all over Malaysia. Prior to performing Multi Locus Sequence Typing, the isolates were subjected to antimicrobial susceptibility testing and detection of the YLF/BTFC genes and BimA allele. Up to 90.5% of the isolates were sensitive to all antimicrobials tested while resistance was observed for antimicrobials typically administered during the eradication stage of treatment. YLF gene cluster and bimABp allele variant were detected in all the isolates. The epidemiological distribution patterns of the Malaysian B. pseudomallei isolates were analysed in silico using phylogenetic tools and compared to Southeast Asian and world-wide isolates. Genotyping of the 84 Malaysian B. pseudomallei isolates revealed 29 different STs of which 6 (7.1%) were novel. ST50 was identified as the group founder followed by subgroup founders ST376, ST211 and ST84. A low-level diversity is noted for the B. pseudomallei isolates described in this study while phylogenetic analysis associated the Malaysian STs to Southeast Asian isolates especially isolates from Thailand. Further analysis also showed a strong association that implicates agriculture and domestication activities as high-risk routes of infection.
CONCLUSIONS/SIGNIFICANCE: In conclusion, MLST analysis of B. pseudomallei clinical isolates from all states in Malaysia revealed low diversity and a close association to Southeast Asian isolates.