Genotypic detection of β-lactamase-producing Escherichia coli isolates obtained from Seven Crater Lakes of San Pablo, Laguna, Philippines.

The extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is becoming a global public health concern. More comprehensive surveillance of β-lactam resistance in E. coli would improve monitoring strategies and control resistance transmission in contaminated environments.

Host-Associated 16S rDNA-Based Markers for Source Tracking of Fecal Pollution in Laguna Lake, Philippines.

Sources of fecal contamination in Laguna Lake, Philippines, were identified using a library-independent microbial source tracking method targeting host-associated 16S rDNA-based markers. Water samples from nine lake stations were assessed for the presence of the fecal markers HF183 (human), BoBac (cattle), Pig-2-Bac (swine), and DuckBac (duck) from August 2019 to January 2020. HF183 (average concentration = 1.

DNA fingerprinting using BOX-A1R and (GTG) primers identify spatial variations of fecal contamination along Pasig River, Philippines.

Pasig River is one of the most economically important rivers in Metro Manila, Philippines. It traverses some of the region's major cities, and because of its strategic location, it is utilized as a means of transportation, as a source of water for domestic and industrial uses, and for recreational purposes. However, due to population growth, industrialization, and land use, the river's water quality is deteriorating.

Library-independent source tracking of fecal contamination in selected stations and tributaries of Laguna Lake, Philippines.

Laguna Lake is the largest inland freshwater body in the Philippines. Although it is classified to be usable for agricultural and recreational purposes by the country's Department of Environment and Natural Resources (DENR), studies looking at lake ecology revealed severe fecal contamination which contributes to the deterioration of water quality. Determining the sources of fecal contamination is necessary for lake protection and management.

Microbial source tracking of fecal contamination in Laguna Lake, Philippines using the library-dependent method, rep-PCR.

Laguna Lake is an economically important resource in the Philippines, with reports of declining water quality due to fecal pollution. Currently, monitoring methods rely on counting fecal indicator bacteria, which does not supply information on potential sources of contamination. In this study, we predicted sources of Escherichia coli in lake stations and tributaries by establishing a fecal source library composed of rep-PCR DNA fingerprints of human, cattle, swine, poultry, and sewage samples (n = 1,408).

Selecting rep-PCR markers to source track fecal contamination in Laguna Lake, Philippines.

Fecal contamination is one of the factors causing deterioration of Laguna Lake. Although total coliform levels are constantly monitored, no protocol is in place to identify their origin. This can be addressed using the library-dependent microbial source tracking (MST) method, repetitive element sequence-based polymerase chain reaction (rep-PCR) fingerprinting.