Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) expressing Panton-Valentine leukocidin (PVL) have been characterized worldwide, but it has not been done in Egypt. In this study, we analyzed the molecular characteristics of PVL+CA-MRSA in Egypt, compared their genetic patterns with that of PVL+ methicillin-susceptible S. aureus and PVL+CA-MRSA from different countries, and investigated the allelic variations among their lukS-PV and lukF-PV gene sequences. The prevalence of PVL+MRSA was 19.04%. They belonged to different genetic clones with multi-locus sequence types (MLST) 30, 80, and the novel type 1010. ST80 strains showed unique antibiotic resistance profile that was distinguishable from the European ST80 clone: they had no resistance to tetracycline and fusidic acid. Two nonsynonymous substitutions in the lukS-PV gene region and two haplotype variants among these isolates were detected. We revealed that PVL is a good marker for CA-MRSA infections and that PVL+ isolates belonged to different genotypes.
Two-dimensional electrophoresis (2DE) combined with mass spectrometry was used to characterize the exo-proteome secreted by two strains (ER13 and ER21) representing community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) belonging to clonal complex 80 (CC80). Common spots were detected between the 2 gels using the Progenesis SameSpots software. Two hundred and fifty-one and 312 spots from the exo-proteome of ER13 and ER21 were resolved, respectively. 2DE overlap comparison showed that 59 spots were shared. LC-MS/MS analysis identified 57 proteins from these spots comprising about 21% extracellular, 48% cytoplasmic, 2% cytoplasmic membrane, 2% cell wall, and 26% with unknown localization. The identified proteins were classified with respect to their Gene Ontology (GO) annotation as ∼24% virulence determinants and toxins, ∼17% involved in carbohydrate metabolism, ∼14% involved in environmental stress, and ∼12% associated with cell division. The identification of the enterotoxin B from the exo-products of both strains used in our study, as belonging to CC80 was interesting.
In recent years, electronic (e)-cigarettes have dramatically increased in popularity as an alternative to conventional cigarettes. Little is known about the effects of e-cigarette vapor (EV) on bacteria that colonize the nasopharynx, including methicillin-resistant Staphylococcus aureus (MRSA). As most cases of pneumonia can be traced to bacteria in a patient's nasopharynx, increased virulence in potential pathogens could have direct consequences clinically for these patients. And because bacterial colonizers are spread between humans, increased virulence in one subject has implications for the community. There is accumulating evidence that exposure to cigarette smoke (CS) increases the pathogenicity of MRSA, as well as its dampening effects on the host immune system. EV exposure has also been demonstrated to increase MRSA virulence both in vitro and in a murine model of pneumonia. In this chapter, we will compare the virulence changes reported in MRSA exposed to CS vs. those exposed to EV, as well as proposed mechanisms and therapeutic targets.
Helicobacter pylori, previously known as Campylobacter pylori, is the most famous causative agent of stomach ulcer, duodenal ulcer, gastritis, and gastric cancer and it has a direct relation with other gastric malignancies. It is a ubiquitous organism that is present in a percent of 30-100% of the global population. This percentage varies according to different geographical locations. Clinical manifestation, transmission, method of diagnosis, management of the infection, and even the treatment differs from region to region. In this review, we are concentrating on the above-mentioned factors that affect H. pylori infection epidemiology and we are directing the spotlight towards the epidemiology of this bacterium in Egypt. We have summarized different tools of diagnosis and the most famous modes of transmission of this infection in Egypt and mentioned our recommendations for future research investigation in these aspects. For example, using pulsedfield gel electrophoresis and next-generation sequencing for the full genomic characterization of H. pylori samples from this geographical area.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.