Influence of carbonyl cyanide m-chlorophenyl hydrazone on biofilm dynamics, protease, and siderophore production by Burkholderia pseudomallei.

Efflux pump inhibitors are a potential therapeutic strategy for managing antimicrobial resistance and biofilm formation. This article evaluated the effect of carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on the biofilm growth dynamics and the production of virulence factors by Burkholderia pseudomallei. The effects of CCCP on planktonic, growing, and mature biofilm, interaction with antibacterial drugs, and protease and siderophore production were assessed. CCCP MICs ranged between 128 and 256 µM. The CCCP (128 µM) had a synergic effect with all the antibiotics tested against biofilms. Additionally, CCCP reduced (p < .05) the biomass of biofilm growth and mature biofilms at 128 and 512 µM, respectively. CCCP also decreased (p < .05) protease production by growing (128 µM) and induced (p < .05) siderophore release by planktonic cells (128 µM) growing biofilms (12.8 and 128 µM) and mature biofilms (512 µM). CCCP demonstrates potential as a therapeutic adjuvant for disassembling B. pseudomallei biofilms and enhancing drug penetration.

Emergence of melioidosis in Brazil: a case series.

BACKGROUND: Melioidosis is a serious disease caused by the bacterium Burkholderia pseudomallei which affects humans and animals. It results in a wide spectrum of clinical manifestations, mainly in the respiratory tract, progressing to septic shock and death. CASE PRESENTATION: Herein, we present a series of seven patients (median age: 41 years) with confirmed melioidosis, treated at a public hospital in Piauí State, Brazil between 2019 and 2021. The most common clinical presentations were fever, cough, pneumonia, and abdominal pain. The mean duration of antibacterial therapy with 1 g of meropenem was 28.6 ± 1.1 days. Six patients recovered and one died. The mean hospitalization time was 51.0 ± 39.2 days. CONCLUSIONS: Melioidosis is an emerging infectious disease in Brazil. Health professionals in endemic areas need to be aware of the clinical presentation and appropriate clinical management of the disease because early diagnosis and early initiation of antibiotic therapy can be life-saving.

Effect of fluoxetine on planktonic and biofilm growth and the antimicrobial susceptibility of Burkholderia pseudomallei.

Aim: This study evaluated the effect of fluoxetine (FLU) on planktonic and biofilm growth and the antimicrobial susceptibility of Burkholderia pseudomallei. Materials & methods: The minimum inhibitory concentrations (MICs) for FLU were determined by broth microdilution. Its effect on growing and mature biofilms and its interaction with antibacterial drugs were evaluated by assessing biofilm metabolic activity, biomass and structure through confocal microscopy. Results: The FLU MIC range was 19.53-312.5 µg/ml. FLU eradicated growing and mature biofilms of B. pseudomallei at 19.53-312.5 µg/ml and 1250-2500 µg/ml, respectively, with no structural alterations and enhanced the antibiofilm activity of antimicrobial drugs. Conclusion: These results bring perspectives for the use of FLU in the treatment of melioidosis, requiring further studies to evaluate its applicability.

In vitro effect of the iron chelator deferiprone on the antimicrobial susceptibility and biofilms of Burkholderia pseudomallei.

This study evaluated the effect of the iron chelator deferiprone (DFP) on antimicrobial susceptibility and biofilm formation and maintenance by Burkholderia pseudomallei. Planktonic susceptibility to DFP alone and in combination with antibiotics was evaluated by broth microdilution and biofilm metabolic activity was determined with resazurin. DFP minimum inhibitory concentration (MIC) range was 4-64 µg/mL and in combination reduced the MIC for amoxicillin/clavulanate and meropenem. DFP reduced the biomass of biofilms by 21 and 12% at MIC and MIC/2, respectively. As for mature biofilms, DFP reduced the biomass by 47%, 59%, 52% and 30% at 512, 256, 128 and 64 µg/mL, respectively, but did not affect B. pseudomallei biofilm viability nor increased biofilm susceptibility to amoxicillin/clavulanate, meropenem and doxycycline. DFP inhibits planktonic growth and potentiates the effect of ß-lactams against B. pseudomallei in the planktonic state and reduces biofilm formation and the biomass of B. pseudomallei biofilms.

Imaging manifestations of pulmonary melioidosis: A case series.

Melioidosis is an endemic disease in Southeast Asia and Oceania caused by the gram-negative bacillus Burkholderia pseudomallei. We studied 15 adult patients from Colombia with microbiologically diagnosed pulmonary melioidosis. We reviewed 15 chest X-rays and 10 chest computed tomography (CT) studies. Of the 15 patients, 87% met the criteria for acute infection and 13% met the criteria for chronic infection. The most common findings on chest X-rays were consolidation (86%), nodules (26%), and cavitation (20%). On CT studies, consolidation and nodules were observed in 90% of cases; the areas of consolidation were predominantly located in the basal and central zones in 60%. Areas of cavitation were observed in 50%, pleural effusion in 60%, and mediastinal lymph nodes in 30%. In patients with acute pulmonary melioidosis (n=8), the findings observed were nodules (100%), mixed pattern with nodules and consolidation (87%), pleural effusion (88%), and mediastinal lymph nodes (25%). The two patients with chronic pulmonary melioidosis both had cavitation. Acute lung infection with B. Pseudomallei has radiologic manifestations similar to those of pneumonia due to other causes. In areas where the disease is endemic, it is essential to include acute melioidosis in the differential diagnosis of pulmonary nodules and chronic melioidosis in the differential diagnosis of cavitated chronic lung lesions.

Whitmore's disease in a diabetic patient

Burkholderia pseudomallei is a pathogen found in tropical climates. Clinically, it manifests with a wide variety of nonspecific symptoms. We present the case of a 64-year-old male patient with a his tory of controlled type 2 diabetes mellitus, stage IIIB chronic kidney disease and tuberculosis treated in 2015, who had a prolonged febrile syndrome and chest pain with ischemic electrocardiographic changes. He underwent arteriography which revealed multivessel coronary disease with an indication for open surgical treatment. On his presurgical laboratory tests a chest tomography showed an upper right mediastinal mass, and therefore his procedure was postponed. The mass was studied on an out patient basis with a negative biopsy for malignancy and microorganisms. He subsequently developed asthenia and adynamia over four months, at which time B.pseudomallei was isolated in blood cultures. He was successfully treated with a carbapenem for 15 days and is now receiving maintenance treat ment with no complications. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2319).

Burkhloderia pseudomallei es un patógeno propio de climas tropicales, clínicamente se mani fiesta con una amplia variedad de síntomas inespecíficos, se presenta el caso de un paciente varón de 64 años con antecedente de diabetes mellitus tipo 2 controlada, enfermedad renal crónica estadio 3b y tuberculosis tratada en 2015 que presentaba un síndrome febril prolongado y dolor torácico con cambios isquémicos en el electrocardiograma, que fue llevado a arteriografía con enfermedad coronaria multivaso, con indicación de manejo quirúrgico abierto, en sus laboratorios prequirúrgicos se encuentra tomografía de tórax masa en mediastino superior derecho, por lo que se difiere el procedimiento, esta masa es estudiada de manera ambulatoria con reporte de biopsia negativo para malignidad y microorganismos, posteriormente con astenia y adinamia de cuatro meses, donde en hemocultivos se aisló B. pseudomallei. Fue tratado con éxito con carbapenémico por 15 días, ahora está recibiendo terapia de mantenimiento sin complicaciones. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2319).

A recombinase polymerase amplification lateral flow assay for rapid detection of Burkholderia pseudomallei, the causative agent of melioidosis.

Burkholderia pseudomallei causes a fatal and infectious disease, melioidosis or Whitmore's disease in humans and animals. Melioidosis is present in different parts of the world and is endemic in Southeast Asia and Northern Australia. Accurate diagnosis of melioidosis is difficult due to its common flu-like symptoms, potentially long incubation period and erroneous identification as culture contaminant. Early diagnosis of the disease is essentially required for administration of suitable antibiotics and disease containment. The present study reports a rapid, specific and sensitive recombinase polymerase amplification lateral flow assay for detection of B. pseudomallei. Specific primers and probe were designed and the assay was performed at 41 °C for 20 min in a portable incubator. End products were detected using ready-to-use lateral flow strips. RPA lateral flow assay could detect ≥ 250 fg genomic DNA of B. pseudomallei and ≥ 50 copies of recombinant plasmid harbouring the target DNA sequence. The assay was found to be highly specific and did not cross-react with other bacterial strains. In artificially spiked human blood and urine samples, the detection limit of the assay was 4.8 × 104 and 4.95 × 104 CFU/mL of B. pseudomallei, respectively. The detection limit of assay after 6 h of enrichment of artificially spiked urine samples was found to be 4.95 × 103 CFU/mL of B. pseudomallei. Detection limit in artificially spiked tap water and soil samples was determined to be 7.5 × 102 CFU/mL and 3.3 × 104 CFU per 5 g of B. pseudomallei, respectively.

Melioidosis con endocarditis de válvula protésica / Prosthetic valve endocarditis in melioidosis: case report

Resumen La melioidosis es endémica en varias regiones, con predominio en el Sudeste Asiático, norte de Australia, sur de Asia, China y Taiwán. En Sudamérica, Colombia ocupa el segundo lugar de casos de melioidosis, después de Brasil. Su manifestación clínica es variable, desde una infección asintomática hasta un compromiso multiorgánico con formación de abscesos múltiples y choque séptico. El compromiso cardiaco es inusual, con una incidencia menor del 1%. Se presenta el caso de un varón de 51 años, colombiano, con antecedente de una valvula aórtica mecánica, quien presentó un absceso en la pierna derecha y en la válvula cardiaca protésica, aislándose Burkholderia pseudomallei en hemocultivos y en el cultivo de secreción de la pierna. Fue tratado con meropenem y cotrimoxazol, con una adecuada respuesta clínica, requiriendo un reemplazo valvular aórtico.

Abstract Melioidosis is an endemic disease to several regions and occurs predominantly in Southern Asia, Northern Australia, China and Taiwan. In South America, Colombia is second after Brazil in number of melioidosis cases reported. Clinical manifestation varies from asymptomatic infection to multiorgan compromise involving multiple abscesses and septic shock. Cardiac compromise is infrequent, with an incidence of <1%. We report the case of a 51-year-old patient from Colombia with a mechanical aortic valve who had an abscess in right leg and in the prosthetic valve. Burkholderia pseudomallei was isolated in blood cultures and drained pus from the leg cultures. Patient was treated with meropenem and cotrimoxazole and required aortic valve replacement, resulting in adequate improvement in clinical symptoms.

Disseminated melioidosis in a patient from Nicaragua.

Melioidosis is a disease caused by Burkholderia pseudomallei. Highly endemic areas include tropical Australia and Southeast Asia, though cases have been reported in the Americas. To our knowledge this is the first case to have occurred due to presumed exposure in Nicaragua, demonstrating the need for increased awareness. In addition, the severity of melioidosis also varies widely and more research is needed on the pattern of disease particularly in non-endemic regions.

Subclinical Burkholderia pseudomallei Infection Associated with Travel to the British Virgin Islands.

Phylogenetic analysis of a clinical isolate associated with subclinical Burkholderia pseudomallei infection revealed probable exposure in the British Virgin Islands, where reported infections are limited. Clinicians should consider this geographic distribution when evaluating possible infection among persons with compatible travel history.

Imaging manifestations of pulmonary melioidosis: a case series. / Manifestaciones radiológicas de la melioidosis pulmonar. Serie de casos.

Melioidosis is an endemic disease in Southeast Asia and Oceania caused by the gram-negative bacillus Burkholderia pseudomallei. We studied 15 adult patients from Colombia with microbiologically diagnosed pulmonary melioidosis. We reviewed 15 chest X-rays and 10 chest computed tomography (CT) studies. Of the 15 patients, 87% met the criteria for acute infection and 13% met the criteria for chronic infection. The most common findings on chest X-rays were consolidation (86%), nodules (26%), and cavitation (20%). On CT studies, consolidation and nodules were observed in 90% of cases; the areas of consolidation were predominantly located in the basal and central zones in 60%. Areas of cavitation were observed in 50%, pleural effusion in 60%, and mediastinal lymph nodes in 30%. In patients with acute pulmonary melioidosis (n=8), the findings observed were nodules (100%), mixed pattern with nodules and consolidation (87%), pleural effusion (88%), and mediastinal lymph nodes (25%). The two patients with chronic pulmonary melioidosis both had cavitation. Acute lung infection with B. Pseudomallei has radiologic manifestations similar to those of pneumonia due to other causes. In areas where the disease is endemic, it is essential to include acute melioidosis in the differential diagnosis of pulmonary nodules and chronic melioidosis in the differential diagnosis of cavitated chronic lung lesions.

Melioidosis in Children, Brazil, 1989-2019.

We studied 20 confirmed or suspected cases of melioidosis in children in Ceará, Brazil, during 1989-2019. We observed a high death rate, severe signs and symptoms, and substantial environmental exposure. These data suggest that childhood melioidosis might be more severe in Brazil than in other regions.

Description of two fatal cases of melioidosis in Mexican children with acute pneumonia: case report.

BACKGROUND: Melioidosis is an infectious disease caused by Burkholderia pseudomallei. In Mexico, the disease is rarely diagnosed in humans and there is no evidence of simultaneous environmental isolation of the pathogen. Here, we describe clinical profiles of fatal cases of melioidosis in two children, in a region without history of that disease. CASE PRESENTATION: About 48 h before onset of symptoms, patients swam in a natural body of water, and thereafter they rapidly developed fatal septicemic illness. Upon necropsy, samples from liver, spleen, lung, cerebrospinal fluid, and bronchial aspirate tissues contained Burkholderia pseudomallei. Environmental samples collected from the locations where the children swam also contained B. pseudomallei. All the clinical and environmental strains showed the same BOX-PCR pattern, suggesting that infection originated from the area where the patients were swimming. CONCLUSIONS: The identification of B. pseudomallei confirmed that melioidosis disease exists in Sonora, Mexico. The presence of B. pseudomallei in the environment may suggest endemicity of the pathogen in the region. This study highlights the importance of strengthening laboratory capacity to prevent and control future melioidosis cases.

Genomic Diversity of Burkholderia pseudomallei Isolates, Colombia.

We report an analysis of the genomic diversity of isolates of Burkholderia pseudomallei, the cause of melioidosis, recovered in Colombia from routine surveillance during 2016-2017. B. pseudomallei appears genetically diverse, suggesting it is well established and has spread across the region.

Burkholderia pseudomallei in Soil, US Virgin Islands, 2019.

The distribution of Burkholderia pseudomallei in the Caribbean is poorly understood. We isolated B. pseudomallei from US Virgin Islands soil. The soil isolate was genetically similar to other isolates from the Caribbean, suggesting that B. pseudomallei might have been introduced to the islands multiple times through severe weather events.

Rhamnolipid enhances Burkholderia pseudomallei biofilm susceptibility, disassembly and production of virulence factors.

Aim: This study evaluated the effect of the biosurfactant rhamnolipid on the antimicrobial susceptibility, biofilm growth dynamics and production of virulence factors by Burkholderia pseudomallei. Materials & methods: The effects of rhamnolipid on planktonic and biofilm growth and its interaction with antibacterial drugs were evaluated. Then, its effects on growing and mature biofilms and on protease and siderophore production were assessed. Results: Rhamnolipid did not inhibit B. pseudomallei growth, but significantly enhanced the activity of meropenem and amoxicillin-clavulanate against mature biofilms. Rhamnolipid significantly reduced the biomass of mature biofilms, significantly increased protease production by growing and mature biofilms and siderophore release by growing biofilms. Conclusion: Rhamnolipid enhances the antimicrobial activity against B. pseudomallei, assists biofilm disassembly and alters protease and siderophore production by bacterial biofilms.

MELIOIDOSIS IN A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) AFTER A HURRICANE IN THE CARIBBEAN ISLANDS.

Melioidosis is an emerging infectious disease of humans and animals caused by the bacterium Burkholderia pseudomallei and endemic in tropical regions, principally Southeast Asia and northern Australia. In September 2017, after Hurricane Maria impacted the Dolphin Discovery facility in the Federation of St. Kitts and Nevis, a juvenile male bottlenose dolphin (Tursiops truncatus) died within 96 hr of presenting with acute anorexia, lethargy, and respiratory distress. Histopathology demonstrated necrohemorrhagic bronchopneumonia, necrotizing hepatitis, splenitis, and lymphadenitis, with intralesional Gram-negative bacilli. B. pseudomallei was confirmed by bacteriological culture and DNA sequencing. This case emphasizes the challenges of melioidosis diagnosis, the importance of awareness for both early detection and efficacious treatment, and recognition in tropical regions where it has been either not reported or underreported. To the authors' knowledge, this is the first case of cetacean melioidosis in the Caribbean Islands, an often severe and fatal disease with increasing prevalence on the American continent.

Three New Cases of Melioidosis, Guadeloupe, French West Indies.

Melioidosis has been detected in the Caribbean, and an increasing number of cases has been reported in the past few decades, but only 2 cases were reported in Guadeloupe during the past 20 years. We describe 3 more cases that occurred during 2016-2017 and examine arguments for increasing endemicity.