Genetic insights of antibiotic resistance, pathogenicity (virulence) and phylogenetic relationship of Escherichia coli strains isolated from livestock, poultry and their handlers - a one health snapshot

BACKGROUND

Pathogenic and non-pathogenic strains of Escherichia coli harbouring antibiotic resistance genes (ARGs) from any source (clinical samples, animal settings, or environment) might be transmitted and contribute to the spread and increase of antibiotic resistance in the biosphere. The goal of this study was to investigate the genome to decipher the repertoire of ARGs, virulence genes carried by E. coli strains isolated from livestock, poultry, and their handlers (humans), and then unveil the genetic relatedness between the strains.

METHODS

Whole genome sequencing was done to investigate the genetic makeup of E. coli isolates (n = 20) [swine (n = 2), cattle (n = 2), sheep (n = 4), poultry (n = 7), and animal handlers (n = 5)] from southern India. The detection of resistome, virulome, biofilm forming genes, mobile genetic elements (MGE), followed by multilocus sequence typing (MLST) and phylogenetic analyses, were performed.

RESULTS

E. coli strains were found to be multi drug resistant, with a resistome encompassing > 20 ARGs, the virulome-17-22 genes, and > 20 key biofilm genes. MGE analysis showed four E. coli isolates (host: poultry, swine and cattle) harbouring composite transposons with ARGs/virulence genes (blaTEM, dfr, qnr/nleB, tir, eae,and esp) with the potential for horizontal transfer. MLST analyses revealed the presence of ST937 and ST3107 in both livestock/poultry and their handlers. Phylogenomic analyses with global E. coli isolates (human/livestock/poultry hosts) showed close relatedness with strains originating from different parts of the world (the United States, China, etc.).

CONCLUSION

The current study emphasizes the circulation of strains of pathogenic sequence types of clinical importance, carrying a diverse repertoire of genes associated with antibiotic resistance, biofilm formation and virulence properties in animal settings, necessitating immediate mitigation measures to reduce the risk of spread across the biosphere.

Genomic insights of beta-lactamase producing Klebsiella quasipneumoniae subsp. similipneumoniae belonging to sequence type 1699 from retail market fish, India

Klebsiella quasipneumoniae is a recently described species and often misidentified as Klebsiella pneumoniae. Here, we report the genomic characterization of Klebsiella quasipneumoniae subsp. similipneumoniae (India238 strain) isolated from fish. The annotated genome acknowledged the presence of bla_CTX-M-15, bla_OKP-B-1, fosA5, oqxAB and virulence genes. The strain with ST1699 and serotypes KL52 and OL103 also harboured insertion sequences (ISs): ISKpn26 and ISEc9. Three complete phage genomes were identified in contigs 1 and 6 of the bacterial genome, enhancing the prospects of genome manipulation. The study highlights the pitfall of conventional microbiological identification methods to distinguish K. pneumoniae and K. quasipneumoniae. This is the first Indian study documenting the incidence of extended-spectrum beta-lactamase (ESBL)-producing K. quasipneumoniae subsp. similipneumoniae from a non-clinical environment, equipped with virulomes and associated mobile genetic elements. Given that fish can act as a potential vector for transmission of antimicrobial resistance genes, our findings have paramount importance on human health.

Whole-genome sequence analysis of Staphylococcus aureus from retail fish acknowledged the incidence of highly virulent ST672-MRSA-IVa/t1309, an emerging Indian clone, in Assam, India

The epidemiology and toxigenicity of MRSA in the fishery environment are poorly understood. In this study, methicillin-resistant Staphylococcus aureus (MRSA) (n = 1) and methicillin-susceptible S. aureus (MSSA) (n = 2) from retail fish were subjected to comprehensive genome analysis. Here, we report the occurrence of ST672-MRSA-IV/t1309 and ST5-MSSA/t105 for the first time from India in the fishery environment. The resistome of the isolates was in concordance with their phenotypic resistance pattern. Phenotypically, the resistance profile of MSSA isolates (n = 2) was AMP-CLI-ERY-NOR-PEN. For MRSA (n = 1), it was AMP-CFZ-CLI-ERY-NOR-OXA-PEN. The antibiotic efflux genes and mutations in the antibiotic target accounted for fluoroquinolone resistance whereas methicillin resistance was conferred through possession of a mecA gene. Similarly, all three isolates carried a similar array of virulence factors. The conjugative plasmid inc18 and rep family 10 plasmids were found in two of the three isolates. This study documents the MRSA carrying SCCmec IVa elements which are the markers of community-associated MRSA (CA-MRSA). Through the possession of SCCmec IV elements, which are smaller than other types of SCCmec, MRSA can contribute to the rapid dissemination of antimicrobial resistance and virulence factors. In short, our findings highlighted that the presence of ST672-MRSA in fishery environments may pose a risk to human health.

α-MoO3 nanostructure on carbon cloth substrate for dopamine detection

Orthorhombic molybdenum oxide (α-MoO₃) nanostructures were deposited on the surface of carbon cloth (CC) as a flexible and high conductive scaffold by reactive RF magnetron sputtering technique. Structure and morphology of the as prepared molybdenum coated carbon cloth (MoO₃CC) were thoroughly characterized with field emission scanning electron microscopy, x-ray diffraction, energy dispersive x-ray and Raman spectroscopy. Benefiting from high surface area and superior conductivity of CC as well as electrocatalytic activity of α-MoO₃ nanostructures, an electrochemical sensor was fabricated. The electrochemical behavior of this new sensor toward determination of dopamine was studied in detail by cyclic voltammetry, amperometry (AM) and square wave voltammetry (SWV). Results reported here reveal that using SWV not only enhances the sensitivity of sensors to dopamine by more than 14 times compared to AM, but also offers higher linear dynamic range (1-700 μM compared to 5-550 μM). Limit of detection, for signal to noise ratio 3, was calculated to be 0.48 μM. Applicability of the proposed sensor for measurement of dopamine in real samples, like urine and pharmaceutical formulation, was also evaluated that concluded to satisfactory results.

Association of polymorphisms in leptin receptor gene with obesity and type 2 diabetes in the local population of Coimbatore

BACKGROUND:

Candidate gene association studies are very relevant to the area of clinical pharmacology. As information on candidate genes and candidate single nucleotide polymorphisms increases, a number of such candidates can be studied in a population to explore their association with their susceptible disease. One such attractive and popular Single Nucleotide Polymorphism (SNP) candidate for obesity is the gene coding for leptin receptor. The leptin receptor gene (LEPR) polymorphism plays an important role in obesity and type 2 diabetes. But the role of this polymorphism is not yet studied in Indian population. Hence, the study focused to explore the association of leptin receptor polymorphisms (K109R, Q223R and K656N) with obesity and type 2 diabetes in both diabetic and non-diabetic subjects recruited from the local population of Coimbatore.

MATERIALS AND METHODS:

Genotypic analysis for the three polymorphisms has been made for 300 subjects (150 diabetic and 150 non-diabetic) with the age range of 40–60 years using conventional Polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) techniques in a case–control fashion. Allele frequencies were estimated based on the gene count method. Correlation was made with phenotypic variables including body mass index (BMI), waist-to-hip ratio (WHR), insulin and leptin levels for those polymorphisms.

RESULTS AND CONCLUSION:

Among the polymorphisms tested in this study, significant association with BMI (P < 0.05), WHR (P < 0.05) leptin (P < 0.001) and insulin (P < 0.0001) was observed for the SNP Q223R, whereas in the case of the other two polymorphisms the association was not statistically significant. The significance value was calculated based on the χ² test. The controls are also found to have a higher frequency of homozygous mutants for Q223R and are significantly associated with obesity. These findings support the hypothesis that Q223R polymorphism is associated with obesity. It can be speculated that the controls showing the same allele may develop Type 2 diabetes at a later stage and Q223R can act as a strong marker.