Effects Of Gram-negative Bacteria Research Articles

The Effect of Gram Negative Bacteria on Semen Parameters of a Sample of Infertile Men and Antibiotic Susceptibility Tests

The most Gram statistically significant cause of male infertility is male urogenital tract infection, being related to 8%-35% of male infertility. The detrimental effect of bacterial infection on male infertility was in no whole agreement. The aim of this work showed the influence of Gram negative bacteria on semen quality among infertile males. A total of 50 semen specimens were collected from infertile men and 50 samples from the healthy individual as the control group were attending Kamal Al-Sammrai Hospital / Baghdad during the period 25 May 2020 to 15 October 2020. Bacteriospermia identification in semen specimens was first prepared by the classical culture methods and confirmed by Vitek 2 system. The present study revealed that 38% of isolates were Gram negative and 62% was no growth. Escherichia coli (22%) followed by Enterobacter cloacae (4%), Klebsiella pneumonia (4%), and each of Raoultella ornithinolytica, Pseudomonas aeruginosa, and Citrobacter freundii at a percentage (2%) and only one (1%) unidentified. This work indicated that some Gram negative bacteria lead to poor health of seminal fluid. Record of Gram negative bacilli was sensitive to Vancomycin, Rifampicin, and Trimmethoprim/sulfamethoxazole combination drug while Fusidicacid was resistant from most Gram negative bacilli. Semen investigation for bacterial detection in infertile males should be done regularly because bacteria may be hurting the semen quality.

Crosstalk Between Nuclear Glucose-Regulated Protein 78 and Tumor Protein 53 Contributes to the Lipopolysaccharide Aggravated Apoptosis of Endoplasmic Reticulum Stress-Responsive Porcine Intestinal Epithelial Cells

Background/Aims: Lipopolysaccharides (LPSs) act as virulence factors that trigger intestinal inflammation and thereby compromise the production of pigs worldwide. Intestinal diseases and dysfunction have been attributed to endoplasmic reticulum stress (ERS) and the subsequent apoptosis of intestinal epithelial cells. Therefore It is important to explore whether LPSs aggravate ERS-mediated apoptosis of intestinal epithelial cells. Methods: ERS and inflammation models were established in porcine cell line J2 (IPEC-J2) and the cells were treated with tunicamycin or LPS at specific times. The expression of marker proteins was determined by western blot and immunofluorescence. Possible crosstalk between proteins was analyzed by co-immunoprecipitation. Small interfering RNA transfection was employed to verify the mechanisms. Results: We found that Escherichia coli-derived LPS aggravated ERS and ERS-mediated apoptosis in ERS-responsive IPEC-J2 cells. The crosstalk between nuclear glucose-regulated protein 78 (GRP78) and tumor protein 53 (p53) was verified to trigger this LPS-aggravated apoptosis of ERS-responsive intestinal cells. Conclusion: This novel finding implies that intestinal malfunctions might solely originate from the effects of Gram-negative bacteria on ERS-responsive intestinal cells. The regulation of ERS signaling (especially the crosstalk between nuclear GRP78 and p53) in ERS-responsive/rapidly growing intestines may help intestinal cells survive from Gram-negative bacterial infections.

Synthesis of oleic acid coated iron oxide nanoparticles and its role in anti-biofilm activity against clinical isolates of bacterial pathogens

In the present study, iron oxide nanoparticles (IONPs) were synthesized using the solvothermal method. The surface of the IONPs was modified with oleic acid (OA) and its role in anti-biofilm activity against clinical isolates of bacterial pathogens was studied. The physiochemical properties of OA-IONPs were characterized using vibrating sample magnetometer, X-ray diffraction, Fourier transform infrared, dynamic light scattering and scanning electron microscopy. The biofilm inhibitory effect of OA-IONPs was tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa). The OA-IONPs showed a potent biofilm inhibitory effect in the case of Gram-positive bacteria and a less significant effect in Gram-negative bacteria. Further, enhanced biofilm inhibition was achieved against both the bacteria using external magnetic target and confirmed using fluorescence microscopy. In conclusion, OA-IONPs can be used as an effective surface modifier for biomaterials to prevent biofilm formation.

Targeting Bacterial RNA Polymerase: Promises for Future Antisense Antibiotics Development

The progress of transcription is synthesized by complex molecules, among which DNA-dependent RNA polymerase (RNAP) is the central enzyme. The prokaryotic RNAP is a large protein composed of core subunits (α2, β and β') and a σ factor that is required for specific recognition of the promoter site and the initiation of transcription. Despite its ubiquity, structural and functional similarities, bacterial RNAPs do not share extensive sequence homology with eukaryotic RNAPs. Bacterial RNAP an attractive target for the development of anti-bacterial drugs as its inactivation would lead to bacterial cell death. This review will present the state of knowledge on the assembly and function of RNAP subunits in bacteria with special focus on insights provided by structural analysis of a key component σ factor. Thorough retrospection has been provided for better understanding of progress and problems in targeting RNAP by traditional chemical compounds. Recent progress using innovative strategies including structural biology and phage based screening, especially the antisense technology, has shed light on developing the first set of macro-molecule RNAP inhibitors. In particular, exploration on targeting RNAP σ70 for realization of broad spectrum antisense bactericidal effect in gram negative bacteria presents the first successful example of PNA-peptide conjugate showing attractive potential as conventional broad-spectrum antibiotics, in which possible way the antisense antibiotics might develop into to meet the range and type of usage in future health care.

Pattern recognition receptors and interleukin-8 mediate effects of Gram-positive and Gram-negative bacteria on lung epithelial cell function.

Lung epithelial cells express pattern recognition receptors, which react to bacteria. We have evaluated the effect of Gram-positive and Gram-negative bacteria on interleukin-8 (CXCL8) release from epithelial cells and the integrity of the epithelial barrier. Primary cultures of human airway epithelial cells and the epithelial cell line A549 were used, and CXCL8 release was measured after exposure to Gram-negative or Gram-positive bacteria. Epithelial barrier function was assessed in monolayer cultures of A549 cells. Gram-positive bacteria Staphylococcus aureus or Streptococcus pneumoniae, induced release of CXCL8 from human airway epithelial cells. These bacteria also disrupted barrier function in A549 cells, an effect mimicked by CXCL8 and blocked by specific binding antibodies to CXCL8. Gram-negative bacteria Escherichia coli or Pseudomonas aeruginosa induced greater release of CXCL8 than Gram-positive bacteria. However, Gram-negative bacteria did not affect epithelial barrier function directly, but prevented disruption induced by Gram-positive bacteria. These effects of Gram-negative bacteria on barrier function were mimicked by FK565, an agonist of the nucleotide-binding oligomerization domain 1 (NOD1) receptor, but not by the Toll-like receptor (TLR) 4 agonist bacterial lipopolysaccharide. Neither the Gram-negative bacteria nor FK565 blocked CXCL8 release. These data show differential functional responses induced by Gram-negative and Gram-positive bacteria in human lung epithelial cells. The NOD1 receptors may have a role in preventing disruption of the epithelial barrier in lung, during inflammatory states.

Role of the bactericidal/permeability-increasing protein in host defence

Much has been learned recently about the structure and function of 55 kDa bactericidal/permeability-increasing protein (BPI), a member of a genomically conserved lipid-interactive protein family. Analysis of BPI fragments and the crystal structure of human BPI have established that BPI consists of two functionally distinct domains: a potently antibacterial and anti-endotoxin amino-terminal domain (∼20 kDa) and a carboxy-terminal portion that imparts opsonic activity to BPI. A recombinant amino-terminal fragment (rBPI 21) protects animals against the effects of Gram-negative bacteria and endotoxin. In man, rBPI 21 is nontoxic and non-immunogenic and is in Phase II/III clinical trials with apparent therapeutic benefit.

Actinobacillus actinomycetemcomitans and Bacteroides gingivalis activate human peripheral monocytes to produce interleukin-1 and tumor necrosis factor.

The effects of gram-negative bacteria clearly associated with juvenile and adult periodontitis on monokine production were assessed using standard in vitro assay techniques. Actinobacillus actinomycetemcomitans and Bacteroides gingivalis were able to activate human peripheral blood monocytes to produce significant amounts of interleukin-1 (IL-1) and tumor necrosis factor (TNF). These monokines are known to induce osteoclastic bone resorption. An oral gram-positive organism, Staphylococcus epidermidis, was able to induce only modest amounts of IL-1 and TNF, slightly above unstimulated monocyte levels.

Effects of gram-negative bacteria on ureteral structure and function : L. Grana, W. L. Donnellan, and O. Swenson. J Urol. 99: 538. 1968

Effects of gram-negative bacteria on ureteral structure and function : L. Grana, W. L. Donnellan, and O. Swenson. J Urol. 99: 538. 1968

Effects of Gram-negative Bacteria on Ureteral Structure and Function

Effects of Gram-negative Bacteria on Ureteral Structure and Function