Hfq Regulates Efflux Pump Expression and Purine Metabolic Pathway to Increase Trimethoprim Resistance in Aeromonas veronii

Aeromonas veronii (A. veronii) is a zoonotic pathogen. It causes clinically a variety of diseases such as dysentery, bacteremia, and meningitis, and brings huge losses to aquaculture. A. veronii has been documented as a multiple antibiotic resistant bacterium. Hfq (host factor for RNA bacteriophage Qβ replication) participates in the regulations of the virulence, adhesion, and nitrogen fixation, effecting on the growth, metabolism synthesis and stress resistance in bacteria. The deletion of hfq gene in A. veronii showed more sensitivity to trimethoprim, accompanying by the upregulations of purine metabolic genes and downregulations of efflux pump genes by transcriptomic data analysis. Coherently, the complementation of efflux pump-related genes acrA and acrB recovered the trimethoprim resistance in Δhfq. Besides, the accumulations of adenosine and guanosine were increased in Δhfq in metabonomic data. The strain Δhfq conferred more sensitive to trimethoprim after appending 1 mM guanosine to M9 medium, while wild type was not altered. These results demonstrated that Hfq mediated trimethoprim resistance by elevating efflux pump expression and degrading adenosine, and guanosine metabolites. Collectively, Hfq is a potential target to tackle trimethoprim resistance in A. veronii infection.

The effects of ultraviolet disinfection on vancomycin-resistant Enterococcus faecalis

Ultraviolet disinfection could effectively inactivate the antibiotic resistant bacterium vancomycin resistant Enterococcus faecalis, but had a limited removal efficiency for the antibiotic resistance gene–vanB gene.

Draft Genome Sequence of Multidrug-Resistant Proteus mirabilis CKTH01, Isolated from Raw Chicken Meat

Proteus mirabilis CKTH01 is a pathogenic bacterium isolated from raw chicken meat. The genome sequence of P. mirabilis CKTH01 contains genes encoding multidrug efflux pumps, which are the virulence factors of the antibiotic-resistant bacterium. This 3.98-Mb draft genome sequence of P. mirabilis CKTH01 will contribute to the understanding of the distribution of multidrug-resistant P. mirabilis in raw chicken meat at the open markets.

Vibrio parahaemolyticus: The protagonist of foodborne diseases

Food contamination is a worrying condition faced by us today. We often discuss on the food safety aspect and how to manage contamination. Food products can be tainted by bacteria at any level of food production to human consumption, subsequently developing gastroenteritis. The people from developed and developing countries are at high risk from harmful effects of unsafe food. Of all the foodborne pathogens, Vibrio parahaemolyticus has been accounted for many outbreaks globally and still at rise even with proper management methods. V. parahaemolyticus infection occurs as a result of improper food handling and preparation, ability of the bacterium to withstand human gut to launch virulence, antibiotic resistant bacterium, and failure of regulatory bodies to safe-guard food quality. This scenario poses a global health issue that warrants rapid control measures to ensure food safety from production to consumption by consumers. For that reason, this review aims to provide an overview of the epidemiology of V. parahaemolyticus as well as discuss the challenges faced to encounter this bacterium.

Bacteriophage GH15: Developing A Novel Weapon Against MRSA

In recent years, numerous bacterial species have developed antibiotic resistance due to the overuse of antibiotics in the home, health care setting, and in agriculture. Alternative methods of treatment, including phage therapy (PT), have been proposed as solutions to this problem. PT is showing promise as an alternative method of treatment against the bacteria methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a virulent and antibiotic resistant bacterium capable of causing infections of the skin, respiratory system, and various other body systems. In this research proposal, we propose investigating the use of the Staphylococcal bacteriophage (phage) GH15 as a therapeutic agent against MRSA infections due to its broad host range, its lack of bacterial virulence genes, and its strong ability to lyse various strains of MRSA. Specifically, we propose to evaluate the tail fibre genes of GH15 contributing to the phage’s host range, in addition to the ability of the phage to induce antiphage humoral immune responses in human cells, in the interest of exploring GH15 as a therapeutic agent for use in PT, specifically against MRSA.

Genomic Analysis of 48 Paenibacillus larvae Bacteriophages

The antibiotic-resistant bacterium Paenibacillus larvae is the causative agent of American foulbrood (AFB), currently the most destructive bacterial disease in honeybees. Phages that infect P. larvae were isolated as early as the 1950s, but it is only in recent years that P. larvae phage genomes have been sequenced and annotated. In this study we analyze the genomes of all 48 currently sequenced P. larvae phage genomes and classify them into four clusters and a singleton. The majority of P. larvae phage genomes are in the 38–45 kbp range and use the cohesive ends (cos) DNA-packaging strategy, while a minority have genomes in the 50–55 kbp range that use the direct terminal repeat (DTR) DNA-packaging strategy. The DTR phages form a distinct cluster, while the cos phages form three clusters and a singleton. Putative functions were identified for about half of all phage proteins. Structural and assembly proteins are located at the front of the genome and tend to be conserved within clusters, whereas regulatory and replication proteins are located in the middle and rear of the genome and are not conserved, even within clusters. All P. larvae phage genomes contain a conserved N-acetylmuramoyl-l-alanine amidase that serves as an endolysin.

PREVALENCE OF MULTIPLE ANTIBIOTIC RESISTANT AND HAEMOLYSIN PRODUCING BACTERIA IN MARKETED FISH SAMPLES

Sea foods hold one of the greatest potentials to meet current and future demands of proteins to feed the world’s ever-burgeoning population. Fresh seafood is an excellent source of proteins, a good source of minerals, and some vitamins, and it is low in fats, cholesterol, and sodium. Fishery products which are of great importance for human nutrition worldwide and provide clear health benefits. Food borne pathogens are the leading causes of illness and death in less developed countries killing approximately 1.8 million people annually. Bacteria are the most important cause of seafood spoilage. Percentage prevalence of bacterial population in fish samples collected from Ukkadam fish market, Coimbatore was significantly higher during the study period. About 7 fish intestinal samples were then enriched in nutrient broth and cultured. Biochemical test were performed to determine their phenotypic characteristics. The antibiotic resistance pattern and MAR index showed an increased antibiotic resistant bacterium in fish which may severe food borneillness in human. Thehemolytic activity and extracellular protein reveals the frequency of virulence and strong pathogenecity. On this basis, we came to the conclusion that all the isolates are highly pathogenic and cause various food poisoning in humans.

Cwp84, aClostridium difficilecysteine protease, exhibits conformational flexibility in the absence of its propeptide

In recent decades, the global healthcare problems caused byClostridium difficilehave increased at an alarming rate. A greater understanding of this antibiotic-resistant bacterium, particularly with respect to how it interacts with the host, is required for the development of novel strategies for fightingC. difficileinfections. The surface layer (S-layer) ofC. difficileis likely to be of significant importance to host–pathogen interactions. The mature S-layer is formed by a proteinaceous array consisting of multiple copies of a high-molecular-weight and a low-molecular-weight S-layer protein. These components result from the cleavage of SlpA by Cwp84, a cysteine protease. The structure of a truncated Cwp84 active-site mutant has recently been reported and the key features have been identified, providing the first structural insights into the role of Cwp84 in the formation of the S-layer. Here, two structures of Cwp84 after propeptide cleavage are presented and the three conformational changes that are observed are discussed. These changes result in a reconfiguration of the active site and exposure of the hydrophobic pocket.