Urinary tract infection and sepsis causing potential of multidrug-resistant Extraintestinal pathogenic E. coli isolated from plant-origin foods

The dissemination of Extraintestinal pathogenic Escherichia coli (ExPEC) in food is a critical concern for human health and food safety. The present study is the first to systematically examine the diverse plant-origin foods such as cucumber, carrot, tomato, radish, chilli, fenugreek, coriander, peppermint, spring onion, cabbage, and spinach for the presence of ExPEC or specific putative ExPEC pathotypes with an in-depth assessment of their phylogenetics, virulence, and drug resistance. A total of 77 (15.9 %) ExPEC isolates were recovered from 1780 samples of the diverse plant-origin foods of distinct environments. Specific putative ExPEC pathotypes such as Uropathogenic E. coli (UPEC, 23.3 %) and Septicemia-associated E. coli (SEPEC, 24.6 %) were identified among ExPEC isolates. The Clermont revisited new phylotyping method revealed the varied distribution (1-27 %) of specific putative ExPEC pathotypes in the different phylogenetic lineages such as A, D/E, B1, and Clade 1, etc. All putative ExPEC pathotypes possess multiple genes (4.3-92.8 %) or phenotypes (3.3-100 %) associated with their virulence. In-vitro antimicrobial susceptibility testing of all putative ExPEC pathotypes demonstrated the presence of 100 % multidrug resistance with moderate to high (52-100 %) resistance to drugs used as last-resorts (chloramphenicol, colistin) or frontline (nitrofurantoin, sulfamethoxazole, ampicillin, gentamicin) in ExPEC-associated infections in humans. Overall, the present findings significantly contribute to our better understanding of the presence of ExPEC in the non-clinical niche, such as plant-origin foods with a possible consequence on human health and food safety.

Extraintestinal pathogenic Escherichia coli (ExPEC) reservoirs, and antibiotics resistance trends: a one-health surveillance for risk analysis from "farm-to-fork"

Extraintestinal pathogenic Escherichia coli (ExPEC) associated infections are significant health concerns for both animals and humans. ExPEC strains are associated with various infections in humans, i.e. urinary tract infections, meningitis, septicemia, and other infections. Over the few years, several studies revealed, food animals act as a reservoir for ExPEC pathovars, but there is no information about the agricultural sector. In particular, the extensive use of antibiotics in food animals and agricultural settings could be significantly contributed to the emergence of antibiotic-resistant pathogens. However, global outbreaks of food-borne illnesses from contaminated food have made a significant concern for both public health and food safety. This review focuses on the reservoirs for ExPEC and their potential circulation between animals, humans, and environment. In this, we first report that the agricultural setting could be the reservoir of ExPEC and can play a role in disseminating antimicrobial-resistant ExPEC. A thorough understanding of ExPEC ecology, reservoirs, and transmission dynamics can significantly contribute to reducing the burden of ExPEC-associated infections. Overall, the study provides the important data on the current state of knowledge for different reservoirs with dynamic, dissemination, and transmission of antimicrobial-resistance ExPEC in animals, humans, and environment in the "One-Health" context.

Biodegradation of malathion by Micrococcus sp. strain MAGK3: kinetics and degradation fragments

Malathion is widely used as an agricultural insecticide, but its toxic nature makes it a serious environmental contaminant. To screen indigenous bacteria for malathion degradation, a strain MAGK3 capable of utilizing malathion as its sole carbon and energy source was isolated from Pennisetum glaucum agricultural soil. Based on morphological and biochemical characteristics and 16S rDNA sequence analysis, strain MAGK3 was identified as Micrococcus aloeverae. The strain was cultured in the presence of malathion under aerobic and energy-restricting conditions, and it grew well in MSM containing malathion (1000 µl/L), showing the highest specific growth rate at 500 µl/L_. Reverse-phase UHPLC-DAD analysis indicated that 100%, 90.48%, 84.27%, 75.46%, 66.65%, and 31.96% of malathion were degraded within 15 days in liquid culture augmented with 50, 100, 200, 300, 500, and 1000 µl/L concentrations of commercial malathion, respectively. Confirmation of malathion degradation to malathion mono, diacids, and phosphorus moiety was performed by Q-TOF-MS analysis, and a pathway of biodegradation was proposed. The influence of co-substrates was also examined to optimize biodegradation further. Kinetic studies based on different models were conducted, and the results demonstrated good conformity with the first-order model. Malathion degradation process by Micrococcus aloeverae was characterized by R² of 0.95, and the initial concentration was reduced by 50% i.e. (DT50) in 8.11 d at an initial concentration of 500 µl/L. This establishes the Micrococcus sp. as a potent candidate for active bioremediation of malathion in liquid cultures as it can withstand high malathion load and can possibly impact the development strategies of bioremediation for its elimination.

Leafy greens as a potential source of multidrug-resistant diarrhoeagenic Escherichia coli and Salmonella

A continued rise in leafy green-linked outbreaks of disease caused by pathogenic Escherichia coli or Salmonella, particularly strains exhibiting multidrug resistance (MDR), has emerged as a major threat to human health and food safety worldwide. Thus, the present study was conducted to examine antimicrobial resistance, including MDR, in diarrhoeagenic E. coli (DEC) and Salmonella isolates obtained from leafy greens from rural and urban areas of India. Of the collected samples (830), 14.1 and 6.5% yielded 117 E. coli (40 DEC and 77 non-DEC) and 54 Salmonella isolates, respectively. Among the DEC pathotypes, enteroaggregative E. coli was the most prevalent (10.2 %), followed by enteropathogenic E. coli (9.4 %), enteroinvasive E. coli (7.6 %) and enterohemorrhagic E. coli (6.8 %). Antimicrobial susceptibility testing of all bacterial isolates with respect to drugs categorized as critically or highly important in both human and veterinary medicine revealed moderate to high (30-90%) resistance for amoxicillin/clavulanic acid, ampicillin, gentamycin and colistin, but relatively low resistance (>30 %) for ciprofloxacin, trimethoprim/sulfamethoxazole and fosfomycin. Notably, all DEC and more than 90% non-DEC or Salmonella isolates were found to be multidrug-resistant to drugs of both human and animal importance. Overall, the results of the present study suggest that leafy greens are potential reservoirs or sources of multidrug-resistant DEC and Salmonella strains in the rural or urban areas of India.

Poultry-origin extraintestinal Escherichia coli strains carrying the traits associated with urinary tract infection, sepsis, meningitis and avian colibacillosis in India

AIM

In-depth 'One Health' risk assessment of extraintestinal pathogenic Escherichia coli (ExPEC) strains carrying the traits of urinary tract infection, sepsis, meningitis and avian colibacillosis in poultry of India.

METHODS AND RESULTS

A total of 230 E. coli isolates were recovered from chicken samples representing the different sources (faeces vs caeca), stages (poultry farms vs retails butcher shop) or environments (rural vs urban) of poultry in India. Among all poultry-origin E. coli isolates, 49 (21·1%) strains were identified as ExPEC possessing multiple virulence determinants regardless of their association with any specific phylogenetic lineages. Of particular, potentially virulent ExPEC pathotypes, that is, uropathogenic E.coli (UPEC, 20·4%), avian pathogenic E. coli (APEC, 34·6%), septicaemia-associated E. coli (SEPEC, 47·0%) and neonatal meningitis-causing E.39 coli (NMEC, 2·0%) were also detected among all ExPEC strains.

CONCLUSIONS

Our study is the first to assess ExPEC strains circulating in the different settings of poultry in India and significantly demonstrates their potential ability to cause multiple extraintestinal infections both in humans and animals.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data of our study are in favour of the possibility that poultry-origin putative virulent ExPEC pathotypes consequently constitute a threat risk to 'One Health' or for food safety and a great concern for poultry production of India.

Biosynthesis of Silver Nanoparticles Using Cucumis prophetarum Aqueous Leaf Extract and Their Antibacterial and Antiproliferative Activity Against Cancer Cell Lines

Biosynthesized nanoparticles are gaining attention because of biologically active plant secondary metabolites that help in green synthesis and also due to their unique biological applications. This study reports a facile, ecofriendly, reliable, and cost-effective synthesis of silver nanoparticles using the aqueous leaf extract of Cucumis prophetarum (C. prophetarum) and their antibacterial and antiproliferative activity. Silver nanoparticles were biosynthesized using the aqueous leaf extract of C. prophetarum, which acted as a reducing and capping agent. The biosynthesized C. prophetarum silver nanoparticles (Cp-AgNPs) were characterized using different techniques, such as UV-visible spectroscopy, dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX). Phytochemical analysis was performed to determine the phytochemicals responsible for the reduction and capping of the biosynthesized Cp-AgNPs. The antioxidant activity of the biosynthesized nanoparticles was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Their antibacterial activity was checked against Staphylococcus aureus (Gram-positive) and Salmonella typhi (Gram-negative) bacteria. The biosynthesized nanoparticles showed dosage-dependent inhibition activity with a significant zone of inhibition and were more effective toward S. typhi as compared to S. aureus. Their antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on selected cancer cell lines. The IC₅₀ values of Cp-AgNPs on A549, MDA-MB-231, HepG2, and MCF-7 were found to be 105.8, 81.1, 94.2, and 65.6 μg/mL, respectively, and this showed that the Cp-AgNPs were more potent toward MCF-7 as compared to other cell lines used in this study. This work revealed that the biosynthesized silver nanoparticles using C. prophetarum leaf extract were associated with good antibacterial activity and antiproliferative potential against selected cancer cell lines. The biosynthesized C. prophetarum AgNPs can be further exploited as a potential candidate for antioxidant, antibacterial, and anticancer agents.

Fibronectin binding protein and Ca2+ play an access key role to mediate pathogenesis in Mycobacterium tuberculosis: An overview

The anomalous distribution of adhesive proteins throughout on the cell surface of the Mycobacterium tuberculosis H₃₇ Rv and their contribution in cell surface adhesion and host-pathogen interaction remain elusive. The completion of M. tuberculosis H₃₇ Rv genome sequence analysis gives some interesting information about polymorphic GC-rich repetitive sequence (PGRS) subfamily of M. tuberculosis that encodes fibronectin binding proteins (FnBP), which have been extensively studied, but the function in the pathogenesis of most of these proteins remains unknown and unclear. This review addresses the M. tuberculosis entry mechanism in the host cell. In particular, an effort has been made to focus on several aspects, (a) association of FnBP encodes by PE_PGRS protein family of M. tuberculosis during host-pathogen interactions. (b) Effect of calcium ions in and outside of the host cell is overriding to maintenance of calcium trafficking in phagocytosis. Furthermore, FnBP may be a potential source of antigenic variation that participating in evoking immune response. M. tuberculosis entry mechanism does not have a major influence alone, involvement of calcium ions, perhaps shed light on host-pathogen interaction relationship, and could open up new avenues for development of novel drug by targeting M. tuberculosis FnBP and blockade of selective adhesions could be useful for therapeutics.