Antibiotic resistance is one of the major health threats facing global as well as domestic populations, however it is not well characterized in pediatric patients. Pediatric patients receiving cancer-directed therapy have several risk factors implicated in development of antibiotic resistance including multiple courses of antibiotics, repeated exposures to the hospital environment, indwelling devices and chemotherapy-related damage to mucosal barriers. The investigators propose to capitalize upon the unique position of St. Jude Global within the global pediatric oncology community by using its regional alliance network to describe the molecular epidemiology of antibiotic resistance in Gram-negative bacteria in this population.

Primary Objectives

1. Describe the epidemiology and the phenotypic and previously determined molecular determinants of antimicrobial resistance in Gram-negative organisms isolated from pediatric diagnostic specimens in selected Central American and US sites with capacity to treat pediatric cancer
2. Utilize strain typing by whole genome sequencing to describe relatedness between organisms at participating sites

Participating clinical microbiology laboratories will flag any Gram-negative bacteria meeting inclusion criteria. Bacteria will be subcultured; one sample will be lysed and shipped to St. Jude; the remaining sample will be stored onsite for the duration of the study. Samples of bacteria from both oncology and non-oncology patients will be included. Whole genome sequencing will be performed on the bacterial samples at St. Jude and the genotypic and phenotypic antimicrobial resistance testing (AST) results compared. Genotypic results will additionally be used to describe phylogenetic relationships and potential transmission events both within and between sites.

Each participating location will collect limited clinical data corresponding to disease and treatment related factors on the affected patient. This will include sociodemographic variables, oncologic diagnosis, treatment phase, presence of a central venous catheter or other foreign body, antibiotic treatment within the past month, and previous history of colonization or infection by a resistant organism.

Inclusion Criteria:

• Pediatric (0-18 years of age) patients having a bacteria isolated from a sterile site (blood, cerebrospinal fluid, body fluid) or urine positive for a Gram-negative bacteria nonsusceptible to at least 1 of the following: third generation cephalosporin, fourth generation cephalosporin or carbapenem OR screening positive for carbapenemase or extended spectrum beta lactamase (ESBL) production.

Exclusion Criteria:

• Repeated isolation of the same organism from the same patient within the study period.

Pediatric (0-18 years of age) patients having a bacteria isolated from a sterile site (blood, cerebrospinal fluid, body fluid) or urine positive for a Gram-negative bacteria nonsusceptible to at least 1 of the following: third generation cephalosporin, fourth generation cephalosporin or carbapenem OR screening positive for carbapenemase or extended spectrum beta lactamase (ESBL) production.