Burkholderia pseudomallei Infection in US Traveler Returning from Mexico, 2014

Reassessing the distribution of Burkholderia pseudomallei outside known endemic areas using animal serological screening combined with environmental surveys: The case of Les Saintes (Guadeloupe) and French Guiana

BACKGROUND

Melioidosis, an emerging infectious disease that affects both humans and animals, is caused by the soil-dwelling bacterium Burkholderia pseudomallei. It is endemic in South and Southeast Asia, and northern Australia, causing an estimated 165,000 human cases annually worldwide. Human cases have been reported in the French West Indies (Martinique and Guadeloupe) since the 1990s. Conversely, no human cases have been reported in French Guiana, a French territory in South America. Our study aimed to investigate whether B. pseudomallei is locally established in Guadeloupe and French Guiana using animals as a proxy.

METHODOLOGY/PRINCIPAL FINDINGS

Blood samples were collected from different animals from 56 farms in French Guiana (n = 670) and from two goat farms in Les Saintes (n = 31), part of the archipelago of Guadeloupe and tested by enzyme-linked immunosorbent assay (ELISA). In Les Saintes, a serological follow-up was performed, and soil, water and goat rectal swabs were collected and analyzed by culture and PCR. The highest seroprevalence rates (39%) were observed in goats in Les Saintes, followed by horses (24%) and cattle (16%) in French Guiana. In the two goat farms, supplementary analyses detected B. pseudomallei from one goat rectal swab, and a B. pseudomallei strain was isolated from the soil.

CONCLUSIONS/SIGNIFICANCE

Our animal serological data suggest the presence of B. pseudomallei in Les Saintes and French Guiana. In Les Saintes, environmental surveys confirmed the endemicity of the bacteria, which is consistent with documented human cases of melioidosis on the island. We did not conduct an environmental survey in French Guiana. Nevertheless, our serological results call for local environmental surveys and a retrospective reassessment of human infections with melioidosis-like symptoms.

Melioidosis: Emerging beyond endemic areas

ABSTRACT

Recent cases suggest that melioidosis, an infection caused by Burkholderia pseudomallei, is an emerging infectious disease. Nurses have a key role in the care of patients with melioidosis. This article provides an overview of the epidemiology, clinical presentation, diagnosis, treatment, and prevention of melioidosis, and discusses unusual, non-travel-related cases of melioidosis.

Evaluating the role of Burkholderia pseudomallei K96243 toxins BPSS0390, BPSS0395, and BPSS1584 in persistent infection

Burkholderia pseudomallei is the causative agent of melioidosis, a disease with a mortality rate of up to 40% even with treatment. Despite the ability of certain antibiotics to control initial infection, relapse occurs in treated patients. The inability of antibiotics to clear this bacterial infection is in part due to persistence, an evasion mechanism against antibiotics and the effect of host defenses. Evaluation of antibiotic efficacy against B. pseudomallei revealed that up to 48% of in vitro grown populations can survive in a persister state. Toxin-antitoxin (TA) systems have been previously implicated in modulating bacterial persistence. We generated three isogenic TA mutants and found that loss of each toxin gene did not alter antibiotic persistence or macrophage survival. In response to macrophage-induced persistence, all three toxin mutants demonstrated increased intracellular susceptibility to levofloxacin which in part was due to the inability of the mutants to induce persistence after nitric oxide or nutrient starvation. In an inhalational model of murine melioidosis, both ΔBPSS0395 and ΔBPSS1584 strains were attenuated, and treatment with levofloxacin led to significant reduction in lung colonisation and reduced splenic colonisation by ΔBPSS0395. Based on our findings, these toxins deserve additional evaluation as putative therapeutic targets.

Persistent Burkholderia pseudomallei Bacteremia in A Filipino Immigrant to the United States: A Case Report

Melioidosis is rare in the United States and endemic to Southeast Asia and Australia. Treatment includes an initial intensive phase of intravenous ceftazidime or meropenem monotherapy depending on severity. The following report describes a case of persistent bacteremia with ceftazidime failure and prolonged meropenem therapy on a ceftazidime-susceptible strain of Burkholderia pseudomallei.

CNS Melioidosis in a Traveler Returning from Cabo, Mexico

Melioidosis is caused by the gram-negative bacillus Burkholderia pseudomallei, endemic to northern Australia and Southeast Asia. We present a patient who traveled to Mexico, returned to the United States, and developed progressive manifestations of melioidosis, culminating as central nervous system disease. Standard therapy was contraindicated, and a prolonged intensive phase was employed.

Phylogeography of Burkholderia pseudomallei Isolates, Western Hemisphere

The bacterium Burkholderia pseudomallei causes melioidosis, which is mainly associated with tropical areas. We analyzed single-nucleotide polymorphisms (SNPs) among genome sequences from isolates of B. pseudomallei that originated in the Western Hemisphere by comparing them with genome sequences of isolates that originated in the Eastern Hemisphere. Analysis indicated that isolates from the Western Hemisphere form a distinct clade, which supports the hypothesis that these isolates were derived from a constricted seeding event from Africa. Subclades have been resolved that are associated with specific regions within the Western Hemisphere and suggest that isolates might be correlated geographically with cases of melioidosis. One isolate associated with a former World War II prisoner of war was believed to represent illness 62 years after exposure in Southeast Asia. However, analysis suggested the isolate originated in Central or South America.

Melioidosis in Mexico, Central America, and the Caribbean

Burkholderia pseudomallei is the causative agent of melioidosis, an endemic disease in tropical areas around the world. Cumulative human cases have demonstrated that melioidosis is prevalent and increasingly recognized in the American continent. Even though the first reports of melioidosis in Mexico, Central America, and the Caribbean Islands date back to the late 1940s, the potential of the disease as a public health concern in the region has not been fully appreciated. Unfortunately, recent studies predicting the global distribution of the disease and the demonstration of melioidosis endemicity in Puerto Rico have not increased recognition of the disease by health professionals in this region. Furthermore, a lack of both diagnostic capacity and awareness of the disease has resulted in a limited number of studies that have attempted to accurately determine its prevalence and geographical distribution. In this review, a summary of reported cases in the countries of this region are presented, as well as recommendations to increase the diagnosis and awareness of the disease as an important public health problem in Mexico, Central America, and the Caribbean islands.