We describe the ecological niche of the human and animal pathogen Pythium insidiosum within endemic agricultural areas of Thailand. Samples were collected from irrigation water, including rice paddy fields, irrigation channels and reservoirs. Zoospores of P. insidiosum were captured from water by the use of a sterile human hair baiting technique. Pythium isolates were identified based on phenot...

Since its emergence in the 1990s, White Spot Disease (WSD) has had major economic and societal impact in the crustacean aquaculture sector. Over the years shrimp farming alone has experienced billion dollar losses through WSD. The disease is caused by the White Spot Syndrome Virus (WSSV), a large dsDNA virus and the only member of the Nimaviridae family. Susceptibility to WSSV in a wide range o...

Legionella pneumophila is a motile intracellular pathogen of macrophages and amoebae. When nutrients become scarce, the bacterium induces expression of transmission traits, some of which are dependent on the flagellar sigma factor FliA (sigma(28)). To test how particular components of the L. pneumophila flagellar regulon contribute to virulence, we compared a fliA mutant with strains whose flag...

From 1999 to 2006, we sampled > 1200 amphibians for the fungal pathogen Batrachochytrium dendrobatidis (Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab-PCR as...

The mucosal barriers of catfish (Ictalurus spp) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient adsorption, osmoregulation, waste excretion, and environmental sensing. Catfish depend more heavily on mucosal barriers than their terrestrial counterparts as they are contin...

Salmonella spp. are gram-negative bacteria capable of causing diseases in a wide range of aquatic and terrestrial animals, including humans. Sea and terrestrial turtles have been recognized as carriers of this zoonotic pathogen. In this project, conventional and molecular diagnostic methods were combined to investigate the prevalence of Salmonella enterica in leatherback sea turtles (Dermochely...

Pathogenic life styles can lead to highly specialized interactions with host species, potentially resulting in fitness trade-offs in other ecological contexts. Here we studied how adaptation of the environmentally transmitted bacterial pathogen, Pseudomonas aeruginosa, to cystic fibrosis (CF) patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7) and protist (Te...

Lateral gene transfer (LGT) has been crucial in the evolution of the cholera pathogen, Vibrio cholerae. The two major virulence factors are present on two different mobile genetic elements, a bacteriophage containing the cholera toxin genes and a genomic island (GI) containing the intestinal adhesin genes. Non-toxigenic V. cholerae in the aquatic environment are a major source of novel DNA that...

Serratia marcescens is the etiological agent of acroporid serratiosis, a distinct form of white pox disease in the threatened coral Acropora palmata. The pathogen is commonly found in untreated human waste in the Florida Keys, which may contaminate both nearshore and offshore waters. Currently there is no direct method for detection of this bacterium in the aquatic or reef environment, and cult...

Fishes inhabit the microbe-rich aquatic environment, hence are constantly under the threat of being infected with the microbial pathogens. Non-specific immune system of fish forms the first line of defense in protecting them from the invading pathogens. Tolllike receptors (TLRs) are important components of non-specific immunity that play an essential role in the recognition of the pathogens bas...