Letters in Applied Microbiology

Aeromonas dhakensis is reported as an emerging pathogenic species within the genus Aeromonas and is widely distributed in tropical coastal areas. This study provided a detailed description and characterization of a strain of A. dhakensis (202108B1) isolated from diseased Ancherythroculter nigrocauda in an inland region of China. Biochemical tests identified the isolate at the genus level, and the further molecular analysis of concatenated housekeeping gene sequences revealed that the strain belonged to the species A...

The efficiency of PCR-based diagnostic assays can be impacted by the quality of DNA template, and anal samples can be particularly problematic due to the presence of faecal contaminants. Here we compared the Quick-DNA Viral Kit (Zymo, Zymo Research, CA) and MagNA Pure 96 DNA and Viral NA Small Volume Kit (MP96, Roche), for use of the Seegene Anyplex II HPV28 assay (Anyplex28, Seegene) with anal samples. Total of 94 anal samples extracted using the MP96 and Zymo kits were tested via the Anyplex28, which detects high-risk human papillomavirus (HR-HPV, Panel A) and low-risk (LR-HPV, Panel B) HPV types...

In this study, we evaluated the antimicrobial activity of bacteria isolated from the marine sponges Hymeniacidon perlevis and Halichondria panicea against seven Acinetobacter baumannii strains, the majority of which were clinically relevant carbapenem-resistant Acinetobacter baumannii (CRAb) strains. We observed the inhibitory activity of 18 (out of 114) sponge-isolated bacterial strains against all A. baumanii strains using medium-throughput solid agar overlay assays. These inhibitory strains belonged to the genera Lactococcus, Pseudomonas and Vagococcus...

Species from Candida parapsilosis complex are frequently found in neonatal candidemia. The antifungal agents to treat this infection are limited and the occurrence of low in vitro susceptibility to echinocandins such as micafungin has been observed. In this context, the chaperone Hsp90 could be a target to reduce resistance. Thus, the objective of this research was to identify isolates from the C. parapsilosis complex and verify the action of Hsp90 inhibitors associated with micafungin. The fungal identification was based on genetic sequencing and mass spectrometry...

Citrus canker is a disease caused by the Gram-negative bacterium Xanthomonas citri subp. citri (X. citri), which affects all commercially important varieties of citrus and can lead to significant losses. Fruit sanitization with products such as chlorine-based ones can reduce the spread of the disease. While effective, their usage raises concerns about safety of the workers. This work proposes essential oils (EOs) as viable alternatives for fruit sanitization. EOs from Cymbopogon species were evaluated as to their antibacterial activity, their effect on the bacterial membrane, and their ability to sanitize citrus fruit...

Colicin (Col) plasmid contains colicin encoding genes arranged in an operon controlled by an SOS inducible promoter. Therefore, any external stresses to the host cell can induce the expression of the downstream genes in the Col operon including a lysis gene. The lysis protein is involved in the extracellular release of colicin through lysis of the producer cells which causes a decline in culture turbidity. However, it is not yet known that E. coli cells with ColE9-J plasmid hold the same level of cell death at the population level following a set of induced conditions...

The poultry industry is very important agricultural and industrial sector in Tunisia and Nigeria, with little information about occurrence of diarrheagenic Escherichia coli in the farmers and chickens. This study aimed to detect the prevalence of diarrhoeal E. coli in humans and poultry, and to investigate plasmid-mediated quinolone resistance (PMQR) genes in both countries. Seventy-four isolates of E. coli were studied; nine different virulence genes were screened by PCR. Serotyping was performed only for pathotypes as well as the determining of antibiotic resistance profiles against 21 antibiotics...

Environmental pollution with aromatic and aliphatic hydrocarbons caused by oil and petrochemical industries has very toxic and carcinogenic effects on living organisms and should be removed from the environment. In this research, after analyzing the oil sludge of the Bahregan area, it was found that most aliphatic paraffin compounds are related to octadecane, most liquid aliphatic compounds are related to hexadecane and most aromatic compounds are related to Naphthalene, Phenanthrene, Fluoranthene, and Anthracene...

Seleniivibrio woodruffii strain S4T is an obligate anaerobe belonging to the phylum Deferribacterota. It was isolated for its ability to respire selenate and was also found to respire arsenate. The high-quality draft genome of this bacterium is 2.9 Mbp, has a G+C content of 48%, 2,762 predicted genes of which 2,709 are protein-coding and 53 RNA genes. An analysis of the genome focusing on the genes encoding for molybdenum-containing enzymes (molybdoenzymes) uncovered a remarkable number of genes encoding for members of the dimethylsulfoxide reductase family of proteins (DMSOR), including putative reductases for selenate and arsenate respiration, as well as genes for nitrogen-fixation...

We investigated bile salts' ability to induce phenotypic changes in biofilm production and protein expression of pathogenic Escherichia coli strains. For this purpose, 82 pathogenic E. coli strains isolated from humans (n = 70), and animals (n = 12), were examined for their ability to form biofilms in the presence or absence of bile salts. We also identified bacterial proteins expressed in response to bile salts using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-electrophoresis) and Liquid Chromatography-Mass Spectrometry (LC-MS/MS)...

Bacterial wilt is a widespread and devastating disease that impacts the production of numerous crucial crops worldwide. The main causative agent of the disease is Ralstonia solanacearum. Due to the pathogen's broad host range and prolonged survival in the soil, it is challenging to control the disease with conventional strategies. Therefore, it is of great importance to develop effective alternative disease control strategies. In recent years, phage therapy has emerged as an environmentally friendly and sustainable biocontrol alternative, demonstrating significant potential in controlling this severe disease...

There is growing interest in using autochthonous lactic acid bacteria (LAB) that provide unique sensory characteristics to dairy products without affecting their safety and quality. This work studied the capacity of three Brazilian indigenous non-starter LABs (NSLAB) to produce biogenic amines (BAs) and evaluated their effect on the volatile organic compounds (VOCs), microbial LAB communities, and physicochemical profile of short-aged cheese. Initially, the strain's potential for biosynthesis of BAs was assessed by PCR and in vitro assays...

Diagnostic laboratories in Aotearoa New Zealand refer cultures from faecal samples positive for Shiga-toxin genes to the national Enteric Reference Laboratory for isolation of Shiga-toxin producing Escherichia coli (STEC) for epidemiological typing. As there was variation in the culture media being referred, a panel of 75 clinical isolates of STEC, representing 28 different serotypes, was used to assess six commercially available media and provide guidance to clinical laboratories. Recommendations were subsequently tested for a three-month period where STEC isolations and confirmations were assessed by whole genome sequencing analysis against the culture media referred...

Lactic acid bacteria, found in heterogenous niches, are known for their health-endorsing properties and are in demand as prospective probiotics. Hence, the scientific community around the globe is in continuous search for novel and new potential strains with extensive applicability and minimum risk. In this context, the present study evaluated the efficiency of Lactiplantibacillus plantarum (P2F2) of human origin, a highly autoaggregating and coaggregating (with pathogens) strain for its colonization, growth promotion, and immunomodulation...

Staphylococcus argenteus has received increased attention from an aspect of food safety since several food poisoning outbreaks caused by the bacterium were reported in Japan. However, S. argenteus prevalence among food handlers and utensils has not yet been investigated. In this study, we investigated S. argenteus prevalence among a collection of coagulase-positive staphylococci (CPS) that were isolated during food sanitary inspections in Japan. Out of a total of 191 CPS isolates, 14 were identified as S. argenteus...

Silver compounds are used in wound dressings to reduce bioburden. Where infection is not rapidly resolved, bacteria may be exposed to sub-therapeutic concentrations of antimicrobial over prolonged periods of time. In this study, a panel of chronic wound bacteria, Pseudomonas aeruginosa (two strains), Staphylococcus aureus and Escherichia coli, were exposed to silver nitrate on agar. Phenotypic characterisation was achieved using broth microdilution sensitivity testing, a crystal violet biofilm assay and a wax moth pathogenesis model...

It is problem that influenza virus infection increases susceptibility to secondary bacterial infection in lung leading to lethal pneumonia. We previously reported that exopolysaccharides (EPS) derived from Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (OLL1073R-1) could prevent against influenza virus infection followed by secondary bacterial infection in vitro. Therefore, the present study assessed whether EPS derived OLL1073R-1 protects the alveolar epithelial barrier disfunction caused by influenza virus infection...

Dermatomycosis is an infection with global impacts caused especially by dermatophytes and Candida species. Current antifungal therapies involve drugs that face fungal resistance barriers. This clinical context emphasizes the need to discover new antifungal agents. Herein, the antifungal potential of ten curcumin analogs was evaluated against five Candida and four dermatophyte species. The most active compound, 3,3'-dimethoxycurcumin (DMC), exhibited Minimum Inhibitory Concentration (MIC) values ranging from 1...

Fishes are the most edible protein source worldwide and generate several remnants such as scales, viscera, head, bone, and skin. Fish wastes are not disposed of properly, which adversely affects the environment, especially the water bodies where fish processing industries dispose of their waste. Fish waste mainly contains nitrogen, oil, fat, salts, heavy metals, and organic compounds, which increase the biological oxygen demand (BOD) and chemical oxygen demand (COD). Fish waste can degrade in various ways, such as physicochemical or by enzymatic action, but using microbes is an environmentally friendly approach that can provide valuable compounds such as products such as collagen, chitin, minerals, and fish protein concentrates...

Endophytic microorganisms associated with medicinal plants are of particular interest as they are a potential source of new bioactive chemicals effective against novel emerging and drug-resistant pathogens. Agave americana is a tropical medicinal plant with antibacterial, antifungal, and anticancer properties. We studied the biodiversity of fungal endophytes of Agave americana and their antimicrobial production potential. Isolated endophytic fungi were classified into 32 morphotypes (15 from stem and 17 from leaf) based on their cultural and morphological characteristics...