New alk genes detected in Antarctic marine sediments

Alkane monooxygenases (Alk) are the key enzymes for alkane degradation. In order to understand the dispersion and diversity of alk genes in Antarctic marine environments, this study analysed by clone libraries the presence and diversity of alk genes (alkB and alkM) in sediments from Admiralty Bay, King George Island, Peninsula Antarctica. The results show a differential distribution of alk genes between the sites, and the predominant presence of new alk genes, mainly in the pristine site. Sequences presented 53.10-69.60% nucleotide identity and 50.90-73.40% amino acid identity to alkB genes described in Silicibacter pomeroyi, Gordonia sp., Prauserella rugosa, Nocardioides sp., Rhodococcus sp., Nocardia farcinica, Pseudomonas putida, Acidisphaera sp., Alcanivorax borkumensis, and alkM described in Acinetobacter sp. This is the first time that the gene alkM was detected and described in Antarctic marine environments. The presence of a range of previously undescribed alk genes indicates the need for further studies in this environment.

The Challenges of Antimicrobial Resistance in Brazil

Brazil is a country with continental proportions with high geographic and economic diversity. Despite its medical centers of excellence, antimicrobial resistance poses a major therapeutic challenge. Rates of methicillin-resistant Staphylococcus aureus are up to 60% and are related to an endemic Brazilian clone. Local resistance to vancomycin in Enterococci was first related to Enterococcus faecalis, which differs from European and American epidemiology. Also, local Klebsiella pneumoniae and Escherichia coli isolates producing extended-spectrum beta-lactamases have a much higher prevalence (40%-50% and 10%-18%, respectively). Carbapenem resistance among the enterobacteriaceae group is becoming a major problem, and K. pneumoniae carbapenemase isolates have been reported in different states. Among nonfermenters, carbapenem resistance is strongly related to SPM-1 (Pseudomonasaeruginosa) and OXA-23 (Acinetobacter baumannii complex) enzymes, and a colistin-only susceptible phenotype has also emerged in these isolates, which is worrisome. Local actions without loosing the global resistance perspective will demand multidisciplinary actions, new policies, and political engagement.