Bacterial pathogens

Thu, 08/27/2020 - 06:32
Author(s): Mahmoud M. Tawfick, Andrew Rosser, Kumar Rajakumar Fimbriae mediate adhesion of Salmonella enterica organisms to the intestinal epithelium, which is an essential step in the pathogenesis process preceding invasion and/or systemic spread. In addition, Salmonella fimbrial genes transcripts were detected in the blood samples from Salmonella infected human patients, which supports the...
Thu, 08/27/2020 - 06:18
Author(s): Richard K. Gast, Deana R. Jones, Rupa Guraya, Kenneth E. Anderson, Darrin M. Karcher The transmission of Salmonella to humans via contaminated eggs is an international public health concern. S. Enteritidis is deposited inside eggs after colonizing reproductive tissues of infected hens. Diverse housing facility characteristics and flock management practices influence Salmonella...
Thu, 08/27/2020 - 04:02
Interaction of tea phenolics with gut microbiota may play an integral role in the health benefits of these bioactive compounds, yet this interaction is not fully understood. Here, the metabolic fate of epigallocatechin-3-gallate (EGCG) and its impact on gut microbiota were integrally investigated viain vitro fermentation. As revealed by ultrahigh performance liquid chromatography hybrid...
Thu, 08/27/2020 - 02:02
The optimisation tests of sodium percarbonate (biocide) with the formula 2Na2CO3·3H2O2, as a green oxidizing agent for biological deactivation of chicken manure, were carried out. The microbiological analysis of fresh manure which consisted of the enumeration of bacteria, fungi and eggs of intestinal parasites showed that the number of bacteria Enterobacteriaceae, i.e. 8.3 log10CFU/g, and the...
Wed, 08/26/2020 - 16:00
Vibrio cholerae is an autochthonous inhabitant of the aquatic environment. Several molecular methods have been used for typing V. cholerae strains, but there is no proper database for such scheme, including multilocus sequence typing (MLST) for V. cholerae O1 and O139 strains. We used 54 V. cholerae O1 and three O139 strains isolated from clinical and environmental sources and regions of India...
Wed, 08/26/2020 - 10:04
ABSTRACT The facultative intracellular pathogen Listeria monocytogenes, like many related Firmicutes, uses the nucleotide second messenger cyclic di-AMP (c-di-AMP) to adapt to changes in nutrient availability, osmotic stress, and the presence of cell wall-acting antibiotics. In rich medium, c-di-AMP is essential; however, mutations in cbpB, the gene encoding c-di-AMP binding protein B, suppress...
Wed, 08/26/2020 - 08:03
by Carmen Schwechheimer, Kassidy Hebert, Sarvind Tripathi, Praveen K. Singh, Kyle A. Floyd, Elise R. Brown, Monique E. Porcella, Jacqueline Osorio, Joseph T. M. Kiblen, Fernando A. Pagliai, Knut Drescher, Seth M. Rubin, Fitnat H. Yildiz Production of an extracellular matrix is essential for biofilm formation, as this matrix both secures and protects the cells it encases. Mechanisms underlying...
Wed, 08/26/2020 - 08:03
Mucosal-associated invariant T (MAIT) cells are innate T lymphocytes activated by bacteria that produce vitamin B2 metabolites. Mouse models of infection have demonstrated a role for MAIT cells in antimicrobial defense. However, proposed protective roles of MAIT cells in human infections remain unproven and clinical conditions associated with selective absence...
Wed, 08/26/2020 - 06:17
Author(s): Chunxia Li, Xiaodong Sun, Bing Niu, Yuan Jiang, Jielin Yang, Qin Chen Cronobacter spp. is a conditioned pathogen found mainly in milk powder; it can seriously harm infant health. We investigated biofilm formation in eight strains of Cronobacter spp. and found that DSM 18707 had the strongest capacity to form biofilm. Biofilm-related genes bcsA, bcsG, flgJ, and flhE were selected for...
Tue, 08/25/2020 - 22:22
A method based on vapor‐phase advanced oxidation process (AOP) for decontaminating red or green grapes was validated for inactivating Listeria monocytogenes and spoilage molds. A Central Composite Design (CCD) and Response Surface Methodology (RSM) were applied to determine the contribution of UV‐C (254 nm) dose, hydrogen peroxide, and ozone concentration on the lethality toward Aspergillus niger...
Tue, 08/25/2020 - 22:13
Background Most hydroponic lettuce growers harvest and package their marketable size lettuces with an intact root ball. With a high microbial load on the peat moss substrate, there is a risk of microbial transfer unto the edible portion during packaging and throughout the product's shelf life. Since the produce is believed to have no contact with the substrate, no sanitizer wash is performed...
Tue, 08/25/2020 - 16:00
Salmonella Weltevreden is increasingly reported from aquatic environments, seafood, and patients in several Southeast Asian countries. Using genome-wide analysis, we characterized S. Weltevreden isolated from cultured shrimp and tilapia from Vietnam and China to study their genetic characteristics and relatedness to clinical isolates of S. Weltevreden ST-365. The phylogenetic analysis revealed up...
Tue, 08/25/2020 - 16:00
Mycobacterium tuberculosis (Mtb) is extremely recalcitrant to antimicrobial chemotherapy requiring 6 months to treat drug-sensitive tuberculosis (TB). Despite this, 4–10% of cured patients will develop recurrent disease within 12 months after completing therapy. Reasons for relapse in cured TB patients remains speculative, attributed to both pathogen and host factors. Populations of dormant...
Tue, 08/25/2020 - 14:07
Salmonella and avian influenza virus are important pathogens affecting the poultry industry and human health worldwide. In this experimental study, we evaluated the consequences of co-infection of Salmonella enteritidis (SE) with H9N2 avian influenza virus (H9N2-AIV) in chickens. Four groups were included: control group, H9N2-AIV group, H9N2-AIV + SE group, and SE group. Infected chickens were...
Tue, 08/25/2020 - 10:06
ABSTRACT Escherichia coli strain Nissle has been used as a probiotic and therapeutic agent for over a century. Reports suggest that Nissle protects mice from enterohemorrhagic E. coli (EHEC) O157:H7 strains; however, mice are not very susceptible to O157:H7 and are not accurate models for O157:H7 infection in humans. Also, Nissle is closely related to uropathogenic E. coli (UPEC) strain CFT073,...
Tue, 08/25/2020 - 10:05
ABSTRACT Influenza A virus (IAV) causes annual epidemics of respiratory disease in humans, often complicated by secondary coinfection with bacterial pathogens such as Staphylococcus aureus. Here, we report that the S. aureus secreted protein lipase 1 enhances IAV replication in vitro in primary cells, including human lung fibroblasts. The proviral activity of lipase 1 is dependent on its...
Tue, 08/25/2020 - 10:05
ABSTRACT Active efflux of antibiotics preventing their accumulation to toxic intracellular concentrations contributes to clinically relevant multidrug resistance. Inhibition of active efflux potentiates antibiotic activity, indicating that efflux inhibitors could be used in combination with antibiotics to reverse drug resistance. Expression of ramA by Salmonella enterica serovar Typhimurium...
Tue, 08/25/2020 - 10:05
ABSTRACT Colicins are toxins produced and released by Enterobacteriaceae to kill competitors in the gut. While group A colicins employ a division of labor strategy to liberate the toxin into the environment via colicin-specific lysis, group B colicin systems lack cognate lysis genes. In Salmonella enterica serovar Typhimurium (S. Tm), the group B colicin Ib (ColIb) is released by temperate phage-...
Tue, 08/25/2020 - 10:05
ABSTRACT Bacterial lipoproteins (Lpps) are a class of membrane-associated proteins universally distributed among all bacteria. A characteristic N-terminal cysteine residue that is variably acylated anchors C-terminal globular domains to the extracellular surface, where they serve numerous roles, including in the capture and transport of essential nutrients. Lpps are also ligands for the Toll-like...
Tue, 08/25/2020 - 10:05
ABSTRACT Quorum sensing is a chemical communication process in which bacteria use the production, release, and detection of signal molecules called autoinducers to orchestrate collective behaviors. The human pathogen Vibrio cholerae requires quorum sensing to infect the small intestine. There, V. cholerae encounters the absence of oxygen and the presence of bile salts. We show that these two...
Tue, 08/25/2020 - 10:05
ABSTRACT DNA supercoiling (DS) is essential for life because it controls critical processes, including transcription, replication, and recombination. Current methods to measure DNA supercoiling in vivo are laborious and unable to examine single cells. Here, we report a method for high-throughput measurement of bacterial DNA supercoiling in vivo. Fluorescent evaluation of DNA supercoiling (FEDS)...
Tue, 08/25/2020 - 10:05
ABSTRACT A multifunctional autoprocessing repeats-in-toxin (MARTX) toxin plays an essential role in the virulence of many pathogens, including a fulminating human pathogen Vibrio vulnificus. H-NS and HlyU repress and derepress expression of the MARTX toxin gene rtxA in V. vulnificus, respectively. However, little is known about other regulatory proteins and environmental signals involved in rtxA...
Tue, 08/25/2020 - 10:05
ABSTRACT Severe systemic bacterial infections result in colonization of deep tissues, which can be very difficult to eliminate with antibiotics. It remains unclear if this is because antibiotics are not reaching inhibitory concentrations within tissues, if subsets of bacteria are less susceptible to antibiotics, or if both contribute to limited treatment efficacy. To detect exposure to...
Tue, 08/25/2020 - 10:05
ABSTRACT The crust is the outermost spore layer of most Bacillus strains devoid of an exosporium. This outermost layer, composed of both proteins and carbohydrates, plays a major role in the adhesion and spreading of spores into the environment. Recent studies have identified several crust proteins and have provided insights about their organization at the spore surface. However, although...
Tue, 08/25/2020 - 10:04
ABSTRACT Membrane bound acyltransferase-3 (AT3) domain-containing proteins are implicated in a wide range of carbohydrate O-acyl modifications, but their mechanism of action is largely unknown. O-antigen acetylation by AT3 domain-containing acetyltransferases of Salmonella spp. can generate a specific immune response upon infection and can influence bacteriophage interactions. This study...
Tue, 08/25/2020 - 10:04
The Gram-negative enterobacterium Erwinia amylovora causes fire blight disease in apple and pear trees. Lipopolysaccharides and the exopolysaccharide amylovoran are essential E. amylovora virulence factors. We found that mutations to rfbX disrupted amylovoran production and virulence in apple fruits and tree shoots, and that deletion of yibD suppressed the rfbX mutant phenotype. Expression of...
Tue, 08/25/2020 - 08:04
Colistin is an important antibiotic currently used to manage infections caused by multidrug-resistant pathogens in both humans and livestock animals. A new mobile colistin-resistance (mcr-9) gene was recently discovered; this discovery highlighted the need for rigorous monitoring of bacterial resistance against colistin. Salmonella is one of the major pathogens responsible for foodborne illnesses...
Mon, 08/24/2020 - 20:40
by Jared D. Honeycutt, Nicolas Wenner, Yan Li, Susan M. Brewer, Liliana M. Massis, Sky W. Brubaker, Phoom Chairatana, Siân V. Owen, Rocío Canals, Jay C. D. Hinton, Denise M. Monack The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric...
Mon, 08/24/2020 - 20:29
Fosfomycin and nitrofurantoin are antibiotics of choice to orally treat non-complicated urinary tract infections (UTIs) of community origin because they remain active against bacteria resistant to other antibiotics. However, epidemiologic surveillance studies have detected a reduced susceptibility to these drugs. The objective of this study was to determine possible mechanisms of resistance to...
Mon, 08/24/2020 - 18:39
Genomic data for psychrophilic bacteria causing blown pack spoilage (BPS) are limited. This study characterizes the genome of a novel Clostridium gasigenes strain CGAS001 isolated from meat juice sample (MJS) of vacuum-packed lamb meat by comparing it with the type strain C. gasigenes DSM 12272 and five strains representing four other BPS-causing Clostridium sensu stricto species. Phenotypic...
Mon, 08/24/2020 - 18:12
Aims: This study aimed to describe the demographic and geographic patterns of campylobacteriosis in Denmark, Finland, Norway and Sweden during 2000–2015. Methods: All Campylobacter infections notified to national authorities in the four countries during the study period were included. Background data for each notification consisted of patient age, sex, geographical location, presumed origin of...
Mon, 08/24/2020 - 18:05
Author(s): Woo-Ju Kim, Soo-Hwan Kim, Dong-Hyun Kang Hot chili sauce is a type of condiment whose popularity is steadily increasing with the incline of a risk for foodborne outbreaks. The combination effect of 915 MHz microwave and carvacrol was studied to inactivate the foodborne pathogens inoculated in hot chili sauce. The addition of 3.25 mM carvacrol did not change the dielectric properties...
Mon, 08/24/2020 - 18:01
Author(s): Bai Wei, Ke Shang, Se-Yeoun Cha, Jun-Feng Zhang, Min Kang, Hyung-Kwan Jang Salmonella is a type of zoonotic bacteria that represents an economic and public health concern worldwide. Difficulties in sample collection from migratory birds mean little is known about their importance as a reservoir of Salmonella. The present study evaluated the prevalence and potential risk of Salmonella...
Mon, 08/24/2020 - 17:39
ABSTRACT Staphylococcus aureus is a highly significant infection problem in health care centers, particularly after surgery. It has been shown that nearly 80% of S. aureus infections following surgery are the same as those in the anterior nares of patients, suggesting that the anterior nares is the source of the infection strain. This has led to the use of mupirocin ointment being applied nasally...
Mon, 08/24/2020 - 17:38
ABSTRACT It is well understood that the adaptive immune response to infectious agents includes a modulating suppressive component as well as an activating component. We now show that the very early innate response also has an immunosuppressive component. Infected cells upregulate the CD47 "don’t eat me" signal, which slows the phagocytic uptake of dying and viable cells as well as...
Mon, 08/24/2020 - 17:38
The increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is worrisome. Coordinated efforts to better understand global prevalence and risk factors are needed. Developing lower- and middle-income countries need reliable, readily available, and cost-effective solutions for detecting ESBL E. coli to contribute to global surveillance. We evaluated MacConkey agar...
Mon, 08/24/2020 - 17:38
A fundamental, clinical, and scientific concern is how lytic bacteriophage, as well as antibiotics, impact diagnostic positivity. Cholera was chosen as a model disease to investigate this important question, because cholera outbreaks enable large enrollment, field methods are well established, and the predatory relationship between lytic bacteriophage and the etiologic agent Vibrio cholerae share...
Mon, 08/24/2020 - 17:38
Timely and accurate methods for detecting Clostridium perfringens-associated diseases (CPAD) are crucial to improve patient care. A number of studies have evaluated the accuracy of nucleic acid amplification tests (NAAT) in detecting CPAD, but decisive results about their effectiveness have not been reported. We conducted a meta-analysis to evaluate the diagnostic performance of NAAT for...
Mon, 08/24/2020 - 17:38
Salmonella is a highly diverse genus consisting of over 2,600 serovars responsible for high-burden food- and waterborne gastroenteritis worldwide. Sensitivity and specificity of PCR-based culture-independent diagnostic testing (CIDT) systems for Salmonella, which depend on a highly conserved gene target, can be affected by single nucleotide polymorphisms (SNPs), indels, and genomic rearrangements...
Mon, 08/24/2020 - 06:16
Author(s): Zenghai Jiang, Tanveer Muhammad Anwar, Xianqi Peng, Silpak Biswas, Mohammed Elbediwi, Yan Li, Weihuan Fang, Min Yue Foodborne disease is one of the most important public health issues worldwide. Food of animal origin is considered as the main vehicle of transmission to humans. Pigs are carriers of numerous foodborne pathogens, including Salmonella which is linked to pork related...
Mon, 08/24/2020 - 06:13
Author(s): Anas Al-Nabulsi, Tareq Osaili, Amani Sawalha, Amin N. Olaimat, Borhan Aldeen Albiss, Ghadeer Mehyar, Mutamed Ayyash, Richard Holley White brined cheese may serve as an ideal medium for the growth of foodborne pathogens including E. coli O157:H7. The objectives of this study were i) to evaluate the inhibitory effects of zinc oxide (ZnO) nanoparticles against E. coli O157:H7 at 10 or 37...
Mon, 08/24/2020 - 00:00
Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat...
Sun, 08/23/2020 - 00:00
Plasmid-mediated colistin resistance (mcr) determinants are challenging the efficacy of polymyxins against Gram-negative pathogens. Among 10 mcr genes described so far, the major determinants mcr-1 and mcr-3 are found closely linked to hpap2 or dgkA genes, encoding a hypothetical phosphatidic acid phosphatase of type 2 (PAP2) and a diacylglycerol kinase, respectively, whose functions are still...
Sat, 08/22/2020 - 12:01
Background Tuberculosis (TB) control is hindered by absence of rapid tests to identify Mycobacterium tuberculosis (MTB) and detect isoniazid (INH) and rifampin (RIF) resistance. We evaluated the accuracy of the BD MAX multidrug-resistant (MDR)-TB assay (BD MAX) in South Africa, Uganda, India, and Peru. Methods Outpatient adults with signs/symptoms of pulmonary TB were prospectively enrolled....
Sat, 08/22/2020 - 12:01
To the Editor—We read the article by Franz et al [1] with great interest. They performed a pan-genome, spatio-temporal, phylogenetic study of Escherichia coli isolates of O157:H7, a major serotype of Shiga toxin–producing E. coli (STEC), and concluded that E. coli O157:H7 has spread globally by the transportation of cattle. We have the following concerns with this study: (1) reservoir selection...
Sat, 08/22/2020 - 06:26
Author(s): Rui Dong, Xiaojie Qin, Shoukui He, Xiujuan Zhou, Yan Cui, Chunlei Shi, Yiping He, Xianming Shi Non-coding small RNAs (sRNAs) have been recognized as major regulators of bacterial stress response. The sRNA DsrA is known to be involved in acid tolerance response of Salmonella, while its role in the response to other stress factors such as oxidants remains unclear. The aim of this study...
Sat, 08/22/2020 - 06:24
Author(s): Amreeta Sarjit, Joshua T. Ravensdale, Ranil Coorey, Narelle Fegan, Gary A. Dykes The effect of heat against eleven Salmonella strains in model meat juices was examined. Juices from beef, lamb and goat were made from either the fatty layer (FL), muscle (M) or a mixture of both (FLM). The pH of each FLM sample was altered to match the pH of PBS and vice versa to determine the pH effect...
Sat, 08/22/2020 - 02:03
The present study investigated the diversity of culturable rhizobacteria associated with potato (S. tuberosum L.) in Tanzania and assessed their in vitro plant growth-promoting (PGP) activities to deduce their potential as biofertilizers. Potato rhizosphere soil and tuber samples (54 samples in total) were collected from 9 villages in three different agro-ecological regions in Tanzania. A total...
Fri, 08/21/2020 - 22:18
ABSTRACT Salmonellaenterica has been shown to survive in low moisture foods (LMF) for extended periods. The objectives of this study were to statistically identify the effects of environmental stress factors; growth temperature (GTemp), osmotic (Osmo), oxidation (Oxi) and pH on the potential cross‐tolerance effect on the survivability of S. enterica in LMF. A factorial design was utilized to...
Fri, 08/21/2020 - 22:18
This present study revealed the effectiveness of a combined microwave‐ultrasonic pasteurization system on Listeria monocytogenes in bottle gourd juice. Response surface methodology based on the central composite design was employed for optimization with microwave power (W), microwave‐induced temperature (ºC), ultrasound amplitude (%) and ultrasound exposure time (min) as the independent factors....

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