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Research has been conducted on the microbial small-subunit rRNAs. The distribution of these rRNAs in Lake Michigan offshore sediments has been investigated via molecular biological methods, and the results indicate that the nitrogen cycling in these sediments may have a seasonal component.

The universal oligonucleotide hybridization probe S-*-Univ-1390-a-A-18 accurately estimates domain-level community composition of microbes in environmental samples, under low-stringency wash conditions. However, the probe overestimates methanogen rRNA concentrations under high-stringency wash conditions. The universal probe S-*-Univ-1392-a-A-15 gives overestimated results with both high- and low-stringency wash conditions. Defined mixtures of rRNAs from pure cultures and anaerobic digester samples are used for the comparison of the two probes.

Extended multilocus sequence typing (MLST) analysis of atypical Escherichia isolates were performed to identify five novel phylogenetic clades (CI to CV) among isolates from environmental, human, and animal sources. The sample data from evaluation of all Escherichia lineages suggested that CIII, CIV, and CV represent environmentally adapted Escherichia lineages might be more abundant outside the host gastrointestinal tract.

A total of 16 different strains of Microbacterium spp. were isolated from contaminated soil and enriched on the carcinogen, hexavalent chromium [Cr(VI)]. The majority of the isolates (11 of the 16) were able to tolerate concentrations (0.1 mM) of cobalt, cadmium, and nickel, in addition to Cr(VI) (0.5-20 mM). Interestingly, these bacteria were also able to tolerate three different antibiotics (ranges: ampicillin 0-16 µg ml-1, chloramphenicol 0-24 µg ml-1, and vancomycin 0-24 µg ml-1). To gain genetic insight into these tolerance pathways, the genomes of these isolates were assembled and annotated. The genomes of these isolates not only have some shared genes (core genome) but also have a large amount of variability. The genomes also contained an annotated Cr(VI) reductase (chrR) that could be related to Cr(VI) reduction. Further, various heavy metal tolerance (e.g., Co/Zn/Cd efflux system) and antibiotic resistance genes were identified, which provide insight into the isolates' ability to tolerate metals and antibiotics. Overall, these isolates showed a wide range of tolerances to heavy metals and antibiotics and genetic diversity, which was likely required of this population to thrive in a contaminated environment. [ABSTRACT FROM AUTHOR]

The article presents a study regarding environmental occurrence and transport, detection methods, and source tracking of fecal indicator organisms and pathogens in water and mentions information on detection methods like polymerase chain reaction (PCR) and portable and real time monitoring systems.