scholarly journals Effect of the Dexamethasone and the Difenihidramiana on the Degranulation of the Eosinophilic Granular Cell of Tilapia

Author(s):  
Luis Alberto Romano ◽  
Virgínia Fonseca Pedrosa

The aim of this study was to determine the relationship between EGC degranulation in fish injected with formalin-killed Escherichia coli and the effect of dexamethasone, diphenhydramine supplied separately and before formalin-killed E. coli. We performed a quantitative analysis of the number of cell granules and demonstrated that: compared to the EGCs of animals, the injection of dead E. coli with formalin generated degranulation of the EGC, while the administration of dexamethasone alone did not show significant differences with control group animals. The administration of diphenhydramine alone did not show significant differences neither with the animals of the dexamethasone treated group nor with those of the control group. When dexamethasone was administered one hour before the E. coli injection, degranulation was apparently inhibited and the number of granules did not show significant differences either with the animals in the control group or with those treated with dexamethasone. Finally, when this group was compared with the group of animals that were only injected with E. coli, the differences were statistically significant. However, when diphenhydramine was administered one hour before E. coli injection, a critical inhibition of EGC degranulation was evidenced, with a marked increase in the number of granules. All this seems to show that dexamethasone can partially inhibit the release of substances that participate in the inflammatory process. Diphenhydramine, a recognized antihistamine, inhibited degranulation of EGCs. These results suggest that EGC can release histamine like mammalian mast cells.

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1656-1668 ◽  
Author(s):  
Catherine Deschamps ◽  
Olivier Clermont ◽  
Marie Claire Hipeaux ◽  
Guillaume Arlet ◽  
Erick Denamur ◽  
...  

Over the last decade, CTX-M enzymes have become the most prevalent extended-spectrum β-lactamases (ESBLs) worldwide, mostly in Escherichia coli, causing a major health problem. An epidemiological relationship has been established between a rare genotype of E. coli, the D2 genotype, and the presence of CTX-M genes. We investigated this striking association by exploring the genetic backgrounds of 18 D2 genotype CTX-M-producing strains and of the plasmids encoding CTX-M enzymes. The 18 strains had different genetic backgrounds, as assessed by multilocus sequence and O typing, and were associated with various plasmids bearing diverse CTX-M genes. The region encompassing the genetic marker of the D2 genotype (TSPE4.C2) was not correlated with the presence of CTX-M genes. CTX-M-producing D2 strains had far fewer virulence factors than a control group of 8 non-ESBL-producing D2 strains, and an inverse relationship was found between the number of co-resistances associated with the CTX-M gene and the number of virulence factors found in the strain. These findings provide evidence for multiple acquisitions of plasmids carrying CTX-M genes in different D2 genotype strains. They strongly suggest that convergent evolution has occurred, and indicate that there has been selection for the association of a specific genetic background of the strain and the CTX-M gene. This fine-tuning of the relationship between the D2 genotype and CTX-M genes presumably increases the fitness of the strain, indicating a role for the host cell in the acquisition and dissemination of CTX-M genes.


2016 ◽  
Vol 60 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Kai Wang ◽  
Yu Qi ◽  
Shushuai Yi ◽  
Zhihua Pei ◽  
Na Pan ◽  
...  

Abstract Introduction: The aim of the experiment was to establish the enterotoxigenic Escherichia coli K88 (ETEC K88)-induced BALB/c mouse duodenum inflammation model. Material and Methods: Mice were administered different concentrations of E. coli K88 (1.0 × 107-109 CFU/mL) for 3 d by means of an esophageal catheter. Results: The results showed that the treated group expressed several significant clinical symptoms, such as reduced dietary demands and weight loss, an increased presence of IL-1α, TNF-α, and MPO in the peripheral blood, and some pathological changes in the duodenum. On the 6th-8th days, the body weight of the mice was the lowest. On the 8th day, there were significant differences in IL-1α, TNF-α, and MPO levels compared to the control group (P < 0.05), the gap between the duodenum mucous layer and the muscular layer had widened, the number of goblet cells was increased, and the inflammatory infiltrate and inflammation changes in the lamina propria and the mucous layer were the most obvious. Conclusion: The duodenum inflammation was the most severe on day 8; thus, the model was successfully established. In addition, varying concentrations of ETEC K88 did not significantly influence the duodenum inflammation (P > 0.05).


2003 ◽  
Vol 66 (11) ◽  
pp. 2005-2009 ◽  
Author(s):  
XIANGWU NOU ◽  
MILDRED RIVERA-BETANCOURT ◽  
JOSEPH M. BOSILEVAC ◽  
TOMMY L. WHEELER ◽  
STEVEN D. SHACKELFORD ◽  
...  

The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceaeon carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not (P &gt; 0.05) different between cattle designated for chemical dehairing (8.1 and 5.9 log CFU/100 cm2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 log CFU/100 cm2 for APC and EBC, respectively). However, E. coli O157:H7 hide prevalence was higher (P &lt; 0.05) for the control group than for the treated group (67% versus 88%). In contrast to hides, the bacterial levels were lower (P &lt; 0.05) on the treated (3.5 and 1.4 log CFU/100 cm2 for APC and EBC) than the control (5.5 and 3.2 log CFU/100 cm2 for APC and EBC) preevisceration carcasses. Prevalence of E. coli O157:H7 was lower (P &gt; 0.05) on treated than on control preevisceration carcasses (1% versus 50%). These data indicate that chemical dehairing of cattle hides is an effective intervention to reduce the incidence of hide-to-carcass contamination with pathogens. The data also imply that any effective hide intervention process incorporated into beef processing procedures would significantly reduce carcass contamination by E. coli O157:H7.


2021 ◽  
Author(s):  
Heesu Kim ◽  
Dong Gun Lee

Abstract Hydrogen peroxide (H2O2) is a debriding agent that damages the microbial structure and function by generating various reactive oxygen species (ROS). H2O2-produced hydroxyl radical (OH∙) also exert oxidative stress on microorganisms. The spread of antibiotic resistance in bacteria is a serious issue worldwide, and greater efforts are needed to identify and characterize novel antibacterial mechanisms to develop new treatment strategies. Therefore, this study aimed to clarify the relationship between H2O2 and Escherichia coli and to elucidate a novel antibacterial mechanism(s) of H2O2. Following H2O2 exposure, increased levels of 8-hydroxyldeoxyguanosine and malondialdehyde indicated that H2O2 accelerates oxidation of bacterial DNA and lipids in E. coli. As oxidative damage worsened, the SOS response was triggered. Cell division arrest and resulting filamentation were identified in cells, indicating that LexA was involved in DNA replication. It was also verified that RecA, a representative SOS gene, helps self-cleavage of LexA and acts as a bacterial caspase-like protein. Our findings also showed that dinF is essential to preserve E. coli from H2O2-induced ROS, and furthermore, demonstrated that H2O2-induced SOS response and SOS genes participate differently in guarding E. coli from oxidative stress. As an extreme SOS response is considered apoptosis-like death (ALD) in bacteria, additional experiments were performed to examine the characteristics of ALD. DNA fragmentation and membrane depolarization appeared in H2O2-treated cells, suggesting that H2O2 causes ALD in E. coli. In conclusion, our investigations revealed that ALD is a novel antibacterial mode of action(s) of H2O2 with important contributions from SOS genes.


2017 ◽  
Vol 80 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
Daniel L. Weller ◽  
Jasna Kovac ◽  
Sherry Roof ◽  
David J. Kent ◽  
Jeffrey I. Tokman ◽  
...  

ABSTRACT Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.


1986 ◽  
Vol 49 (12) ◽  
pp. 944-951 ◽  
Author(s):  
J. E. KENNEDY ◽  
C. I. WEI ◽  
J. L. OBLINGER

The distribution of coliphages in various foods and the relationship between the incidences of coliphages and bacterial indicators were investigated. A total of 120 food samples comprising twelve products and including fresh meats, shellfish, vegetables and processed meats, were analyzed for indigenous coliphages using Escherichia coli hosts C, C-3000 and B. Bacterial analyses included enumeration of E. coli, fecal coliforms and coliforms, as well as aerobic plate counts and Salmonella analyses. Coliphages were detected (≥10 PFU/100 g) in 56% of samples and eleven of twelve products. Coliphages, E. coli, fecal coliforms and coliforms were recovered at a level of at least 30 organisms per 100 g in 43, 43, 68 and 81% of samples, with overall mean recoveries of 13, 19, 93 and 4300 organisms/100 g, respectively. Highest and lowest recoveries of coliphages and E. coli were from fresh meats and vacuum-packaged processed meats, respectively. Significant nonparametric correlations between coliphages, E. coli, fecal coliforms and coliforms were found among all food samples.


1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.


2015 ◽  
Vol 59 (9) ◽  
pp. 5171-5180 ◽  
Author(s):  
M. A. Fleury ◽  
G. Mourand ◽  
E. Jouy ◽  
F. Touzain ◽  
L. Le Devendec ◽  
...  

ABSTRACTResistance to extended-spectrum cephalosporins (ESCs) is an important health concern. Here, we studied the impact of the administration of a long-acting form of ceftiofur on the pig gut microbiota and ESC resistance inEscherichia coli. Pigs were orally inoculated with an ESC-resistantE. coliM63 strain harboring a conjugative plasmid carrying a gene conferring resistance,blaCTX-M-1. On the same day, they were given or not a unique injection of ceftiofur. Fecal microbiota were studied using quantitative PCR analysis of the main bacterial groups and quantification of short-chain fatty acids.E. coliand ESC-resistantE. coliwere determined by culture methods, and the ESC-resistantE. coliisolates were characterized. The copies of theblaCTX-M-1gene were quantified. After ceftiofur injection, the main change in gut microbiota was the significant but transitory decrease in theE. colipopulation. Acetate and butyrate levels were significantly lower in the treated group. In all inoculated groups,E. coliM63 persisted in most pigs, and theblaCTX-M-1gene was transferred to otherE. coli. Culture and PCR results showed that the ceftiofur-treated group shed significantly more resistant strains 1 and 3 days after ESC injection. Thereafter, on most dates, there were no differences between the groups, but notably, one pig in the nontreated group regularly excreted very high numbers of ESC-resistantE. coli, probably leading to a higher contamination level in its pen. In conclusion, the use of ESCs, and also the presence of high-shedding animals, are important features in the spread of ESC resistance.


2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Subhrajit Bhar ◽  
Tungadri Bose ◽  
Sharmila S. Mande

ABSTRACT Signal transduction systems are essential for microorganisms to respond to their ever-changing environment. They can be distinguished into one-component systems, two-component systems, and extracytoplasmic-function σ factors. Abundances of a few signal-transducing proteins, termed herein as sensory proteins (SPs), have previously been reported to be correlated with the genome size and ecological niche of certain Gram-positive bacteria. No such reports are available for Gram-negative bacteria. The current study attempts to investigate the relationship of the abundances of SPs to genome size in Escherichia coli, and the bacterial pathotypes or phylotypes. While the relationship between SP abundance and genome size could not be established, the sensory protein index (SPI), a new metric defined herein, was found to be correlated with E. coli virulence. In addition, significant association was observed among the distribution of SPs and E. coli pathotypes. Results indicate that such associations might be due to genomic rearrangements to best utilize the resources available in a given ecological niche. Overall, the study provides an in-depth analysis of the occurrence of different SPs among pathogenic and nonpathogenic E. coli strains. Possibilities of using the SPI as a marker for identifying pathogenic strains from among an organism complex are also discussed. IMPORTANCE Sensory proteins (SPs) act as sensors and actuators for a cell and participate in important mechanisms pertaining to bacterial survival, adaptation, and virulence. Therefore, bacterial species residing in similar ecological niches or those sharing common pathotypes are expected to exhibit similar SP signatures. We have investigated profiles of SPs in different species of Escherichia coli and present in this article the sensory protein index (SPI), a metric for quantifying the abundance and/or distribution of SPs across bacterial genomes, which could indicate the virulence potency of a bacterium. The SPI could find use in characterizing uncultured strains and bacterial complexes, as a biomarker for disease diagnostics, evaluating the effect of therapeutic interventions, assessing effects of ecological alterations, etc. Grouping the studied strains of E. coli on the basis of the frequency of occurrence of SPs in their genomes could potentially replicate the stratification of these strains on the basis of their phylotypes. In addition, E. coli strains belonging to the same pathotypes were also seen to share similar SP signatures. Furthermore, the SPI was seen to be an indicator of pathogenic potency of E. coli strains. The SPI metric is expected to be useful in the (pathogenic) characterization of hereto uncultured strains which are routinely sequenced in host microbiome analysis projects, or from among an ensemble of microbial organisms constituting a biospecimen. Thus, the possibilities of using the SPI as a biomarker for diagnosis of a disease or the outcome of a therapeutic intervention cannot be ruled out. Further, SPIs obtained from longitudinal ecological samples have the potential to serve as key indicators of environmental changes. Such changes in the environment are often detrimental to the resident biome and methods for timely detection of environmental changes hold huge socioeconomic benefits.


2016 ◽  
Vol 101 (7-8) ◽  
pp. 304-312 ◽  
Author(s):  
Cagla Bali ◽  
Nejat Altintas ◽  
Ozlem Ozmete ◽  
Ibrahim Gelincik ◽  
Hakan Yabanoglu ◽  
...  

Curcumin has remarkable anti-inflammatory and antioxidant properties. The aim of this study was to investigate the protective effects of curcumin on a rat model of carbapenem-resistant Escherichia coli–induced acute lung injury (ALI). Thirty-two rats were randomly allocated to 4 groups to induce an ALI: negative control group (rats not infected with E coli with no antibiotic treatment), positive control group (rats infected with E coli with no antibiotic treatment), imipenem group (rats infected with E coli that received intraperitoneal injection of imipenem), and the imipenem+curcumin group (rats infected with E coli that received intraperitoneal injection of imipenem and were fed on curcumin).The rats were killed, and lung tissues samples were harvested for biochemical analyses and histopathologic examination. Total antioxidant status (TAS), total oxidant status (TOS), tumor necrosis factor α (TNFα), and interleukin-6 (IL6) were measured. TOS increased in the positive control group (P &lt; 0.001) and decreased in the imipenem and imipenem+curcumin groups (P &lt; 0.001 and P &lt; 0.001, respectively). TAS decreased in the positive control group (P = 0.005). Imipenem treatment did not increase TAS, but the imipenem+curcumin group increased TAS (P = 0.014). TNFα and IL6 increased in the positive control group compared with the negative control group (P &lt; 0.001 and P = 0.010, respectively). Imipenem decreased TNFα (P &lt; 0.001), but did not decrease IL6 (P = 0.418). Imipenem+curcumin decreased TNFα (P &lt; 0.001); this decrease was more pronounced compared with the imipenem group (P = 0.008). IL6 decreased in the curcumin group compared with the positive control group (P = 0.011). Curcumin combined with imipenem can be an alternative therapeutic agent to overcome the resistance of E coli strains.


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