scholarly journals STRESS TOLERANCE AND ANTIBIOTIC SUSCEPTIBILITY OF CRONOBACTER SPP. ISOLATED FROM POWDERED INFANT FORMULA RETAILED IN NIGERIA

2021 ◽  
Vol 9 (6) ◽  
pp. 190-202
Author(s):  
Ezeh Abimbola R ◽  
Smith Stella I. ◽  
Aboaba Olusimbo O
Keyword(s):  
Stress Response ◽  
Mortality Rate ◽  
Stress Tolerance ◽  
Antibiotic Susceptibility ◽  
Zero Tolerance ◽  
Opportunistic Pathogen ◽  
Powdered Infant Formula ◽  
Infant Formulae ◽  
Neonates And Infants ◽  
Different Levels

 ., is an emerging, opportunistic pathogen that causes infections such as , meningitis and in neonates and infants, and can sometimes lead to death. There is zero tolerance for the presence of . all powdered infant formulae because of the high mortality rate (80%) associated with . . Three . (CS14, CS17 and CS124) isolated from PIF retailed in Nigeria were exposed to different levels of stress (pH, osmotic, oxidative, heat, bile and desiccation). The production ability of the isolates was investigated and the susceptibility of the isolates to different antibiotics was carried out using the MIC panel. Variation in stress response was observed in the isolates with no consistent pattern. The CS 17 ( ) and CS 124 ( ) showed the highest tolerance to stress on the average. All the isolates exhibited the ability to produce ranging from 1.30 – 2.0 and were also sensitive to more than 95% of the antibiotics used in the MIC panel, with no resistance to any.

scholarly journals Prevalence of metallo-β-lactamase genes among Pseudomonas aeruginosa isolated from various clinical samples in China

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wei Wang ◽  
Xiaoya Wang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Ethylenediaminetetraacetic Acid ◽  
Carbapenem Resistance ◽  
Opportunistic Pathogen ◽  
Detection Methods ◽  
Clinical Samples ◽  
Routine Practice ◽  
Carbapenem Resistant ◽  
High Prevalence

AbstractBackgroundPseudomonas aeruginosa is an opportunistic pathogen which is associated with nosocomial infections and causes various diseases including urinary tract infection, pneumonia, soft-tissue infection and sepsis. The emergence of P. aeruginosa-acquired metallo-β-lactamase (MBL) is most worrisome and poses a serious threat during treatment and infection control. The objective of this study was to identify antibiotic susceptibility, phenotypic detection of MBL production and to determine the prevalence of MBL genes in carbapenem-resistant P. aeruginosa isolated from different clinical samples.MethodsA total of 329 non-duplicate P. aeruginosa isolated from various clinical samples from two hospitals in China between September 2017 and March 2019 were included in this study. Phenotypic detection of MBL was performed by the combined detection method using imipenem and imipenem-ethylenediaminetetraacetic acid (EDTA) discs. MBL-encoding genes including blaVIM-1, blaVIM-2, blaIMP-1, blaIMP-2, blaSPM-1, blaSIM, blaNDM-1 and blaGIM were detected by polymerase chain reaction (PCR).ResultsOf the 329 P. aeruginosa, majority of the isolates were resistant to imipenem (77.5%) followed by meropenem (64.7%). Of the 270 P. aeruginosa isolates tested, 149 (55.2%) isolates were found to be positive for MBL detection. Of the different samples, 57.8% (n = 26) of P. aeruginosa isolated from blood were found to be positive for MBL production. Of the various MBL genes, blaIMP-1 (28.2%) was the most predominant gene detected followed by blaVIM-2 (18.8%), blaVIM-1 (16.1%), blaNDM-1 (9.4%), blaIMP-2 (6.7%), blaSIM (6.0%), blaSPM-1 (4.0%) and blaGIM (1.3%) genes.ConclusionsThe high resistance of P. aeruginosa toward imipenem and meropenem and the high prevalence of blaIMP-1 and blaVIM-2 set the alarm on the increasing, perhaps the increased, carbapenem resistance. In addition to routine antibiotic susceptibility testings, our results emphasize the importance of both the phenotypic and genotypic MBL detection methods in routine practice for early detection of carbapenem resistance and to prevent further dissemination of this resistant pathogen.

scholarly journals Salivary oxytocin, cognitive anxiety and self-confidence in pre-competition athletes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irene La Fratta ◽  
Sara Franceschelli ◽  
Lorenza Speranza ◽  
Antonia Patruno ◽  
Carlo Michetti ◽  
...  
Keyword(s):  
Stress Response ◽  
State Anxiety ◽  
Young Male ◽  
Soccer Players ◽  
Soccer Match ◽  
Self Confidence ◽  
Cognitive Anxiety ◽  
Psychophysiological Stress ◽  
Different Levels

AbstractIt is well known that soccer sport has the potential for high levels of stress and anxiety and that these are linked to Cortisol (C) variations. To date, much research has been devoted to understanding how Oxytocin (OT) can affect anxiety in response to a challenge. The aim of this study was to investigate, in 56 young male soccer players, the psychophysiological stress response 96 and 24 h before one soccer match of a tournament, in order to establish whether athletes who won or lost, show different levels of C and OT or expressions of competitive state anxiety subcomponents. We found that winners had significantly lower Cognitive anxiety and higher Self-confidence scores than losers. Also, significant differences between winners and losers in C and OT concentrations were observed, with higher OT levels in who has won and higher C levels in who has lost. Our results showed interesting associations between OT, C, anxiety feelings, and the outcome of competition.

scholarly journals Autoinducer-2 Triggers the Oxidative Stress Response in Mycobacterium avium, Leading to Biofilm Formation

2008 ◽  
Vol 74 (6) ◽  
pp. 1798-1804 ◽  
Author(s):  
Henriette Geier ◽  
Serge Mostowy ◽  
Gerard A. Cangelosi ◽  
Marcel A. Behr ◽  
Timothy E. Ford
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Quorum Sensing ◽  
Mycobacterium Avium ◽  
Biofilm Formation ◽  
Transcriptional Response ◽  
Opportunistic Pathogen ◽  
Environmental Stresses ◽  
Oxidative Stress Response ◽  
Autoinducer 2

ABSTRACT Mycobacterium avium is an environmental organism and opportunistic pathogen with inherent resistance to drugs, environmental stresses, and the host immune response. To adapt to these disparate conditions, M. avium must control its transcriptional response to environmental cues. M. avium forms biofilms in various environmental settings, including drinking water pipes and potable water reservoirs. In this study, we investigated the role of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation by M. avium. The addition of the compound to planktonic M. avium cultures resulted in increased biofilm formation. Microarray and reverse transcriptase PCR studies revealed an upregulation of the oxidative stress response upon addition of AI-2. This suggests that the response to AI-2 might be related to oxidative stress, rather than quorum sensing. Consistent with this model, addition of hydrogen peroxide, a known stimulus of the oxidative stress response, to M. avium cultures resulted in elevated biofilm formation. These results suggest that AI-2 does not act as a quorum-sensing signal in M. avium. Instead, biofilm formation is triggered by environmental stresses of biotic and abiotic origins and AI-2 may exert effects on that level.

Null mutation in sspA of Cronobacter sakazakii influences its tolerance to environmental stress

2021 ◽  
Author(s):  
Jie Zhan ◽  
Xin Tan ◽  
Xiaoyuan Wang
Keyword(s):  
Stress Tolerance ◽  
Protein A ◽  
Bacterial Chemotaxis ◽  
Water Concentration ◽  
Acid Tolerance ◽  
Opportunistic Pathogen ◽  
Cronobacter Sakazakii ◽  
Knockout Mutant ◽  
Cellular Survival ◽  
E Coli

Cronobacter sakazakii is a known foodborne opportunistic pathogen that can affect the intestinal health of infants. Despite undergoing complex manufacturing processes and low water concentration in the finished product, infant formula has been associated with Cronobacter infections, suggesting that C. sakazakii’s pathogenicity may be related to its tolerance to stress. In this study, the effect of the stringent starvation protein A (SspA), which plays an important role in E. coli cellular survival under environmental stresses, on the stress tolerance of C. sakazakii BAA894 was investigated by creating an sspA-knockout mutant. The effects of this mutation on the acid, desiccation and drug tolerance were assessed, and results showed that acid tolerance decreased, while desiccation tolerance increased in LB and decreased in M9. Moreover, the MICs of 10 antibiotics in LB medium and 8 antibiotics in M9 medium were determined and compared of the wild-type and ΔsspA. Transcriptome analysis showed that 27.21% or 37.78% of the genes in ΔsspA were significantly differentially expressed in LB or M9 media, the genes relevant to microbial metabolism in diverse environments and bacterial chemotaxis were detailed analyzed. The current study contributes towards an improved understanding of the role of SspA in C. sakazakii BAA894 stress tolerance.

Microbiological Guidelines and Sampling Plans for Dried Infant Cereals and Powdered Infant Formula from a Canadian National Microbiological Survey

1980 ◽  
Vol 43 (8) ◽  
pp. 613-616 ◽  
Author(s):  
D. L. COLLINS-THOMPSON ◽  
K. F. WEISS ◽  
G. W. RIEDEL ◽  
S. CHARBONNEAU
Keyword(s):  
Test Organism ◽  
Rejection Rate ◽  
Fecal Coliforms ◽  
Powdered Infant Formula ◽  
Sampling Plans ◽  
Infant Foods ◽  
Hygienic Practice ◽  
Infant Formulae ◽  
Sampling Procedures

The microbiological safety and quality of 130 lots of domestic and imported dried infant cereals and powdered infant formulae were determined using aerobic colony count (ACC), aerobic sporeformers, confirmed and fecal coliforms, Escherichia coli, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens (spores), hemolytic streptococci and yeast and molds. Based on the analytical results and sampling procedures of this survey, no health hazards were found. The results were also used to develop a three-class acceptance plan for ACC (n = 5, c = 2, m = 103/g, M = 104/g), confirmed coliforms (n = 5, c = 1, m = < 1.8/g, M = 20/g) and Salmonella (n = 20, c = 0, m = 0, M = 0). These plans were influenced by the proposed Codex Code of Hygienic Practice for Foods for Infants and Children. Canadian-produced infant foods had an estimate lot rejection rate based on the three-class acceptance plan of 1.1 to 20.3%, based on cereal type and test organism.

scholarly journals Phylogenetics of Molecular Regulators Contributing to Plant Stress Tolerance

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 407
Author(s):  
Xiang Yu ◽  
Yan Bao
Keyword(s):  
Stress Response ◽  
Plant Breeding ◽  
Stress Tolerance ◽  
Wild Species ◽  
Plant Stress ◽  
Gene Families ◽  
Homologous Gene ◽  
Plant Tolerance ◽  
Functional Conservation ◽  
Plant Stress Tolerance

Genetic studies on model plants and crops in the last few decades have uncovered numerous genes that play vital roles in plant tolerance to adverse environments. These genes could be used as targets for genetic engineering to improve plant tolerance to abiotic and biotic stresses. Recent advances in CRISPR-based genome editing have accelerated modern plant breeding and wild-species domestication. However, the stress regulators in many crops and horticultural cultivars and their wild species remain largely unexplored. Thus, transferring the accumulated knowledge of these molecular regulators from model plants to a wider range of other species is critical for modern plant breeding. Phylogenetic analysis is one of the powerful strategies for studying the functional conservation and diversity of homologous gene families among different species with complete genome sequences available. In addition, many transcriptome datasets of plants under stress conditions have been publicly released, providing a useful resource for addressing the stress response of given gene families. This Special Issue aims to illustrate the phylogenetics of molecular regulators with potential in contributing to plant stress tolerance and their stress response diversity in multiple non-model plants.

scholarly journals PQS Produced by the Pseudomonas aeruginosa Stress Response Repels Swarms Away from Bacteriophage and Antibiotics

2019 ◽  
Vol 201 (23) ◽  
Author(s):  
Jean-Louis Bru ◽  
Brandon Rawson ◽  
Calvin Trinh ◽  
Katrine Whiteson ◽  
Nina Molin Høyland-Kroghsbo ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Stress Response ◽  
Antibiotic Treatment ◽  
Bacterial Pathogen ◽  
Warning Signal ◽  
Opportunistic Pathogen ◽  
Evolutionary Strategy ◽  
Swarming Motility ◽  
Content Type ◽  
Bacteriophage Infection

ABSTRACT We investigate the effect of bacteriophage infection and antibiotic treatment on the coordination of swarming, a collective form of flagellum- and pilus-mediated motility in bacteria. We show that phage infection of the opportunistic bacterial pathogen Pseudomonas aeruginosa abolishes swarming motility in the infected subpopulation and induces the release of the Pseudomonas quinolone signaling molecule PQS, which repulses uninfected subpopulations from approaching the infected area. These mechanisms have the overall effect of limiting the infection to a subpopulation, which promotes the survival of the overall population. Antibiotic treatment of P. aeruginosa elicits the same response, abolishing swarming motility and repulsing approaching swarms away from the antibiotic-treated area through a PQS-dependent mechanism. Swarms are entirely repelled from the zone of antibiotic-treated P. aeruginosa, consistent with a form of antibiotic evasion, and are not repelled by antibiotics alone. PQS has multiple functions, including serving as a quorum-sensing molecule, activating an oxidative stress response, and regulating the release of virulence and host-modifying factors. We show that PQS serves additionally as a stress warning signal that causes the greater population to physically avoid cell stress. The stress response at the collective level observed here in P. aeruginosa is consistent with a mechanism that promotes the survival of bacterial populations. IMPORTANCE We uncover a phage- and antibiotic-induced stress response in the clinically important opportunistic pathogen Pseudomonas aeruginosa. Phage-infected P. aeruginosa subpopulations are isolated from uninfected subpopulations by the production of a stress-induced signal. Activation of the stress response by antibiotics causes P. aeruginosa to physically be repelled from the area containing antibiotics altogether, consistent with a mechanism of antibiotic evasion. The stress response observed here could increase P. aeruginosa resilience against antibiotic treatment and phage therapy in health care settings, as well as provide a simple evolutionary strategy to avoid areas containing stress.

scholarly journals High Salt Cross-ProtectsEscherichia colifrom Antibiotic Treatment through Increasing Efflux Pump Expression

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Manlu Zhu ◽  
Xiongfeng Dai
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Antibiotic Treatment ◽  
Antibiotic Susceptibility ◽  
Stress Condition ◽  
Efflux Pump ◽  
Environmental Stresses ◽  
Antimicrobial Treatment ◽  
High Salt ◽  
Protection Effect

ABSTRACTEnvironmental stresses often co-occur when bacteria encounter antibiotic treatment inside the human body. The cellular response to environmental stressors can alter the global gene expression pattern of bacteria. However, the relationship between the cellular stress response and antibiotic susceptibility remains poorly understood. Here we studied the effect of high salt, an important environmental stress condition inside the human body, on bacterial susceptibility to antibiotics. We found that high salt reduces the susceptibility ofEscherichia colito tetracycline and chloramphenicol, leading to a cross-protection effect. The cross-protection effect originates from the increased AcrAB-TolC efflux pump expression level under high-salt conditions. Our study demonstrates that stress-induced gene expression alterations can cross-protect bacteria from antibiotic treatment and should thus be considered when investigating antibiotic susceptibility and applying antimicrobial treatment.IMPORTANCEEnvironmental stresses often co-occur when bacteria confront antibiotic treatment. We provide a clear example that a natural stress condition (high salt) can cross-protect bacteria from antibiotic treatment by triggering the bacterial stress response program (elevated AcrAB-TolC efflux pump expression). Our study highlights the importance of taking the co-occurrence of bacterial environmental stresses into consideration when investigating antibiotic susceptibility and applying antimicrobial treatment.

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