scholarly journals Efflux-Mediated bile Resistance in Gram-Positive Pathogens

2022 ◽  
Author(s):  
Amjed Alsultan ◽  
Dhama Alsallami
Keyword(s):  
Intestinal Tract ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Gastrointestinal Infections ◽  
Gram Positive ◽  
Antimicrobial Substances ◽  
Serious Infections ◽  
Key Factor ◽  
Bile Resistance ◽  
Human Intestinal Tract

Gram-positive pathogens are causing many serious infections that affect humans and result in mild to severe diseases worldwide. In order to survive and initiate infection, enteric pathogens must resist the physiochemical defence factors in the human intestinal tract. One of these defence factors is bile, a potent antibacterial like compound in the intestine. Efflux pumps are the important mechanism by which bacteria resist antibacterial agents such as bile. Efflux of antimicrobial substances outside the bacterial cell is considered as a key factor for intestinal colonization and virulence of enteric pathogens. This paper will review the research conducted on efflux–mediated bile resistance in Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis and Clostridium perfringens. These bacteria colonize in the human & animal gastrointestinal tract and they have a multiple mechanism to resist the innate defences in the gut and antibacterial activity of bile. However, bile resistance in these bacteria is not fully understood. The evidence from this review suggests that Gram-positive pathogens have the ability to active transport of bile. Further research is needed to know how these pathogens sense bile and how bile regulates its virulence factor. In general, therefore, it seems that understanding the specific mechanism of bile resistance in enteric bacteria including gram-positive pathogens may involve in the development of novel strategies to control and treatment of gastrointestinal infections.

scholarly journals Assessment of Murraya koenigii Leaf Extract against New Multiple Drug Resistance Human Enteric Pathogens

2020 ◽  
Vol 32 (10) ◽  
pp. 2647-2652
Author(s):  
Rudrangshu Chatterjee ◽  
Dushyant Singh ◽  
M.L. Aggarwal ◽  
Ajit Varma ◽  
Abhishek Chauhan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Leaf Extract ◽  
Multiple Drug Resistance ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Multi Drug Resistance ◽  
Multiple Drug ◽  
Bacterial Strains ◽  
Murraya Koenigii ◽  
Gastrointestinal Infections

Sewage waters are the primary habitats to harbour antibiotic resistance bacteria (ARB) especially multi-drug resistance (MDR) human enteric pathogens. Microorganisms acquire resistance towards many commercial antibiotics due to their inappropriate use. In this study, human enteric pathogens were isolated, identified and characterized and shows the resistance against five different clinically significant commonly prescribed antibiotics. The bacterial strains were isolated from different sewage treatment plants located in Delhi city, India. Samples were analyzed for the detection of pathogenic human enteric bacteria through morphological, biochemical and molecular analysis. Methanolic leaf extract of Murraya koenigii showed the significant antibacterial activity against multi drug resistant human enteric pathogens. Thus, Murraya koenigii leaves would be a potential alterantive to antibiotic regimens for the prevention of gastrointestinal infections.

scholarly journals The Great ESKAPE: Exploring the Crossroads of Bile and Antibiotic Resistance in Bacterial Pathogens

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Kevin S. Gipson ◽  
Kourtney P. Nickerson ◽  
Eliana Drenkard ◽  
Alejandro Llanos-Chea ◽  
Snaha Krishna Dogiparthi ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Gastrointestinal Transit ◽  
Resistance Mechanisms ◽  
Enteric Pathogens ◽  
Bacterial Burden ◽  
Gastrointestinal Infections ◽  
Content Type ◽  
Bile Resistance ◽  
Pathogen Exposure

ABSTRACT Throughout the course of infection, many pathogens encounter bactericidal conditions that threaten the viability of the bacteria and impede the establishment of infection. Bile is one of the most innately bactericidal compounds present in humans, functioning to reduce the bacterial burden in the gastrointestinal tract while also aiding in digestion. It is becoming increasingly apparent that pathogens successfully resist the bactericidal conditions of bile, including bacteria that do not normally cause gastrointestinal infections. This review highlights the ability of Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter (ESKAPE), and other enteric pathogens to resist bile and how these interactions can impact the sensitivity of bacteria to various antimicrobial agents. Given that pathogen exposure to bile is an essential component to gastrointestinal transit that cannot be avoided, understanding how bile resistance mechanisms align with antimicrobial resistance is vital to our ability to develop new, successful therapeutics in an age of widespread and increasing antimicrobial resistance.

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

Florid Bacillus cereus Infection of the Placenta Associated With Intrauterine Fetal Demise

2021 ◽  
pp. 109352662199902
Author(s):  
Stephanie Shea ◽  
Alberto Paniz-Mondolfi ◽  
Emilia Sordillo ◽  
Michael Nowak ◽  
Fumiko Dekio
Keyword(s):  
Bacillus Cereus ◽  
Placental Tissue ◽  
Maternal Blood ◽  
Gastrointestinal Infections ◽  
Gram Positive ◽  
Fetal Demise ◽  
Placental Infection ◽  
Intrauterine Fetal Demise ◽  
Acute Necrotizing ◽  
Poor Outcomes

Bacillus cereus is a gram-positive, rod-shaped bacterium that is commonly implicated in foodborne illness but has also become increasingly recognized as a source of serious non-gastrointestinal infections, including sepsis, meningitis, and pneumonia. Non-gastrointestinal B. cereus infections have been identified in children, especially in neonates; however, there are no previously described cases of fetal demise associated with B. cereus placental infection. We present a case of acute chorioamnionitis-related intrauterine fetal demise of twin A at 17 weeks gestation, noted two days after selective termination of twin B. Histological examination revealed numerous gram-positive bacilli in placental tissue, as well as fetal vasculature, in the setting of severe acute necrotizing chorioamnionitis and subchorionitis, intervillous abscesses, acute villitis, and peripheral acute funisitis. Cultures of maternal blood and placental tissue both yielded growth of B. cereus. This case underscores the importance of B. cereus as a human pathogen, and specifically demonstrates its potential as an agent of severe intraamniotic and placental infection with poor outcomes for the fetus.

The human intestinal tract – a hotbed of resistance gene transfer? Part I

2007 ◽  
Vol 29 (3) ◽  
pp. 17-21 ◽  
Author(s):  
Abigail A. Salyers ◽  
Kyung Moon ◽  
David Schlesinger
Keyword(s):  
Gene Transfer ◽  
Resistance Gene ◽  
Intestinal Tract ◽  
Human Intestinal Tract

Improved diagnosis of gastrointestinal infections using a semi-automated multiplex real-time PCR for detection of enteropathogens

2021 ◽  
Vol 70 (9) ◽  
Author(s):  
Berta Fidalgo ◽  
Elisa Rubio ◽  
Victor Pastor ◽  
Marta Parera ◽  
Clara Ballesté-Delpierre ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Enteric Pathogens ◽  
Pcr Analysis ◽  
Culture Methods ◽  
Gastrointestinal Infections ◽  
Content Type ◽  
Link Type ◽  
Microbiological Culture ◽  
Micro Organisms

Introduction. The identification of enteropathogens is critical for the clinical management of patients with suspected gastrointestinal infection. The FLOW multiplex PCR system (FMPS) is a semi-automated platform (FLOW System, Roche) for multiplex real-time PCR analysis. Hypothesis/Gap Statement. FMPS has greater sensitivity for the detection of enteric pathogens than standard methods such as culture, biochemical identification, immunochromatography or microscopic examination. Aim.The diagnostic performance of the FMPS was evaluated and compared to that of traditional microbiological procedures. Methodology. A total of 10 659 samples were collected and analysed over a period of 7 years. From 2013 to 2018 (every July to September), samples were processed using standard microbiological culture methods. In 2019, the FMPS was implemented using real-time PCR to detect the following enteropathogens: Shigella spp., Salmonella spp., Campylobacter spp., Giardia intestinalis, Entamoeba histolytica, Blastocystis hominis, Cryptosporidum spp., Dientamoeba fragilis, adenovirus, norovirus and rotavirus. Standard microbiological culture methods (2013–2018) included stool culture, microscopy and immunochromatography. Results. A total of 1078 stool samples were analysed prospectively using the FMPS from July to September (2019): bacterial, parasitic and viral pathogens were identified in 15.3, 9.71 and 5.29 % of cases, respectively. During the same period of 6 years (2013–2018), the proportion of positive identifications using standard microbiological methods from 2013 to 2018 was significantly lower. A major significant recovery improvement was observed for all bacteria species tested: Shigella spp./enteroinvasive Escherichia coli (EIEC) (P <0.05), Salmonella spp. (P <0.05) and Campylobacter spp. (P <0.05). Marked differences were also observed for the parasites G. intestinalis, Cryptosporidium spp. and D. fragilis. Conclusion. These results support the value of multiplex real-time PCR analysis for the detection of enteric pathogens in laboratory diagnosis with outstanding performance in identifying labile micro-organisms. The identification of unsuspected micro-organisms for less specific clinical presentations may also impact on clinical practice and help optimize patient management.

scholarly journals Negligible import of enteric pathogens by newly arrived asylum seekers and no impact on incidence of notified Salmonella and Shigella infections and outbreaks in Rhineland-Palatinate, Germany, January 2015 to May 2016

2018 ◽  
Vol 23 (20) ◽  
Author(s):  
Lutz Ehlkes ◽  
Maja George ◽  
Donald Knautz ◽  
Florian Burckhardt ◽  
Klaus Jahn ◽  
...  
Keyword(s):  
Public Health ◽  
Asylum Seekers ◽  
Enteric Bacteria ◽  
Host Population ◽  
Enteric Pathogens ◽  
German Population ◽  
Target Groups ◽  
Targeted Approach ◽  
Country Specific ◽  
Children Under 5

Introduction The 2015 refugee crisis raised concerns about an import of infectious diseases affecting the German population. Aims: To evaluate public and individual health benefits of stool screening, and explore whether importation of enteric pathogens by newly arrived asylum seekers impacts on the host population. Methods: We used data from mandatory stool screening to determine the overall, age, sex, and country-specific prevalence of enteric bacteria and helminths. We used surveillance data to assess whether the number of incoming asylum seekers influenced notifications of salmonellosis and shigellosis in Rhineland-Palatinate. Results: Salmonella were found in 0.2% (95% confidence interval (CI) 0.2–0.3%) of 23,410 samples collected from January 2015 to May 2016. Prevalence was highest in children under 5 years (0.8%; 95% CI: 0.5–1.3%). No Shigella or invasive Salmonella spp. were detected. In a subset of 14,511 samples, the prevalence of helminth infestation was 2.4% (95% CI: 2.1–2.6%), with highest proportions detected in adolescents (4.6%; 95% CI 3.8–5.4%) and among Eritreans (9.3%; 95% CI: 7.0–12.0%); in the latter particularly Schistosoma mansoni and Taenia spp. The increase in asylum applications did not increase notifications of salmonellosis and shigellosis. No transmission from asylum seekers to German residents was notified. Conclusion: Public health risk associated with imported enteric pathogens is very low overall. Addressing individual and public health risks, we recommend replacing stool screening of all newly arrived asylum seekers by a targeted approach, with target groups and approaches being adapted if necessary. Target groups supported by our data are children, adolescents, and Eritreans.

scholarly journals Genetic analysis of the role of the conserved inner membrane protein CvpA in EHEC resistance to deoxycholate

2020 ◽  
Author(s):  
Alyson R. Warr ◽  
Rachel T. Giorgio ◽  
Matthew K. Waldor
Keyword(s):  
Stress Response ◽  
Membrane Protein ◽  
Bile Salt ◽  
Cell Envelope ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Inner Membrane ◽  
Bacterial Phyla ◽  
E Coli ◽  
Inner Membrane Protein

The function of cvpA, a bacterial gene predicted to encode an inner membrane protein, is largely unknown. Early studies in E. coli linked cvpA to Colicin V secretion and recent work revealed that it is required for robust intestinal colonization by diverse enteric pathogens. In enterohemorrhagic E. coli (EHEC), cvpA is required for resistance to the bile salt deoxycholate (DOC). Here, we carried out genome-scale transposon-insertion mutagenesis and spontaneous suppressor analysis to uncover cvpA’s genetic interactions and identify common pathways that rescue the sensitivity of a ΔcvpA EHEC mutant to DOC. These screens demonstrated that mutations predicted to activate the σE-mediated extracytoplasmic stress response bypass the ΔcvpA mutant’s susceptibility to DOC. Consistent with this idea, we found that deletions in rseA and msbB and direct overexpression of rpoE restored DOC resistance to the ΔcvpA mutant. Analysis of the distribution of CvpA homologs revealed that this inner membrane protein is conserved across diverse bacterial phyla, in both enteric and non-enteric bacteria that are not exposed to bile. Together, our findings suggest that CvpA plays a role in cell envelope homeostasis in response to DOC and similar stress stimuli in diverse bacterial species. IMPORTANCE Several enteric pathogens, including Enterohemorrhagic E. coli (EHEC), require CvpA to robustly colonize the intestine. This inner membrane protein is also important for secretion of a colicin and EHEC resistance to the bile salt deoxycholate (DOC), but its function is unknown. Genetic analyses carried out here showed that activation of the σE-mediated extracytoplasmic stress response restored the resistance of a cvpA mutant to DOC, suggesting that CvpA plays a role in cell envelope homeostasis. The conservation of CvpA across diverse bacterial phyla suggests that this membrane protein facilitates cell envelope homeostasis in response to varied cell envelope perturbations.

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