Alcaligenes faecalis is one of the most important and clinically significant environmental pathogens, increasing in importance due to its isolation from soil and nosocomial environments. The Gram-negative soil bacterium is associated with skin endocarditis, bacteremia, dysentery, meningitis, endophthalmitis, urinary tract infections, and pneumonia in patients. With emerging antibiotic resistance in A. faecalis, it has become crucial to understand the origin of such resistance genes within this clinically significant environmental and gut bacterium. In this research, we studied the impact of antibiotic overuse in poultry and its effect on developing resistance in A. faecalis. We sampled soil and faecal materials from five poultry farms, performed whole genome sequencing & analysis and identified four strains of A. faecalis. Furthermore, we characterized the genes in the genomic islands of A. faecalis isolates. We found four multidrug-resistant A. faecalis strains that showed resistance against vancomycin (MIC >1000 μg/ml), ceftazidime (50 μg/ml), colistin (50 μg/ml) and ciprofloxacin (50 μg/ml). From whole genome comparative analysis, we found more than 180 resistance genes compared to the reference sequence. Parts of our assembled contigs were found to be similar to different bacteria which included pbp1A and pbp2 imparting resistance to amoxicillin originally a part of Helicobacter and Bordetella pertussis. We also found the Mycobacterial insertion element IS6110 in the genomic islands of all four genomes. This prominent insertion element can be transferred and induce resistance to other bacterial genomes. The results thus are crucial in understanding the transfer of resistance genes in the environment and can help in developing regimes for antibiotic use in the food and poultry industry.
Peanut (Arachis hypogaea. L) is an important oil seed crop.
Both arbuscular mycorrhizal fungi (AMF) symbiosis and calcium
(Ca2+) application can ameliorate the impact of saline
soil on peanut production, and the rhizosphere bacterial communities
are also closely correlated with peanut salt tolerance;
however, whether AMF and Ca2+ can withstand high-salinity
through or partially through modulating rhizosphere bacterial
communities is unclear. Here, we used the rhizosphere
bacterial DNA from saline alkali soil treated with AMF and
Ca2+ alone or together to perform high-throughput sequencing
of 16S rRNA genes. Taxonomic analysis revealed that
AMF and Ca2+ treatment increased the abundance of Proteobacteria
and Firmicutes at the phylum level. The nitrogenfixing
bacterium Sphingomonas was the dominant genus in
these soils at the genus level, and the soil invertase and urease
activities were also increased after AMF and Ca2+ treatment,
implying that AMF and Ca2+ effectively improved the living
environment of plants under salt stress. Moreover, AMF combined
with Ca2+ was better than AMF or Ca2+ alone at altering
the bacterial structure and improving peanut growth in saline
alkali soil. Together, AMF and Ca2+ applications are conducive
to peanut salt adaption by regulating the bacterial community
in saline alkali soil.