The pathogenesis of Staphylococcus aureus in autoimmune diseases.

Autoimmune disease are defined as the attacks on host tissue by the immune system. Several factors, e.g. genetic and environmental triggers (in particular, viruses, bacteria, and other infectious pathogens) play a role in the development of autoimmune diseases. Bacterial infections are related to several autoimmune diseases, e.g. chronic inflammations and demyelination. Nowadays, an estimated 20-30% of the general human population carry Staphylococcus aureus (S. aureus). This organism can asymptomatically colonize healthy individuals. S. aureus carriers show no sign of infection and can thus spread this bacterium in the community. Several studies investigated the potential involvement of this bacterium as the etiological agents of autoimmune diseases. The present review focused on the role of S. aureus infections in the pathogenesis of autoimmune, inflammatory, and demyelinating diseases. Possible modes of the pathogenic action of bacteria are discussed in association with the ways in which S. aureus can initiate or exacerbate autoimmunity.

CRISPR Technology in Gene-Editing-Based Detection and Treatment of SARS-CoV-2.

Outbreak and rapid spread of coronavirus disease (COVID-19) caused by coronavirus acute respiratory syndrome (SARS-CoV-2) caused severe acute respiratory syndrome (SARS-CoV-2) that started in Wuhan, and has become a global problem because of the high rate of human-to-human transmission and severe respiratory infections. Because of high prevalence of SARS-CoV-2, which threatens many people worldwide, rapid diagnosis and simple treatment are needed. Genome editing is a nucleic acid-based approach to altering the genome by artificially changes in genetic information and induce irreversible changes in the function of target gene. Clustered, regularly interspaced short palindromic repeats (CRISPR/Cas) could be a practical and straightforward approach to this disease. CRISPR/Cas system contains Cas protein, which is controlled by a small RNA molecule to create a double-stranded DNA gap. Evidence suggested that CRISPR/Cas was also usable for diagnosis and treatment of SARS-CoV-2 infection. In this review study, we discoursed on application of CRISPR technology in detection and treatment of SARS-CoV-2 infection. Another aspect of this study was to introduce potential future problems in use of CRISPR/Cas technology.

Genetic characterization of extensive drug resistant Acinetobacter baumannii: an appalling impediment.

INTRODUCTION: Acinetobacter baumannii infections are a growing public-health concern. The bacterium's potentiality to acquire resistance to a number of commonly used antibiotics has turned it into a formidable pathogen. AIMS: Molecular characterization of extensive drug resistant (XDR) typing of A. baumannii clinical isolates by polymerase chain reaction. MATERIALS AND METHODS: Thirty XDR A. baumannii were investigated for the presence of genes encoding carbapenemase resistance, biofilm capacity, autoinducer synthase, virulence and surface motility by polymerase chain reaction (PCR). Later, the isolates were typed by plasmid-based replicon (Rep) (PBRT) and trilocus sequence typing. RESULTS: All 30 XDR A. baumannii strains displayed genes related to surface motility, autoinducer synthase, virulence determinant, biofilm related genes except PER, and bap, the frequency of which was 83.3% and 76.6%, respectively. Analysis of rep genes showed highest frequency of rep6 and rep2 genes, with frequency of 75% and 65%, respectively. All XDR A. baumannii strains belonged to SG I (European clone II) group. CONCLUSIONS: Our results show the extraordinary plasticity of XDR A. baumannii and suggest that the strains have gained endemicity in our hospital, which could be a great concern in the near future.

Virulence characterization of Klebsiella pneumoniae and its relation with ESBL and AmpC beta-lactamase associated resistance.

BACKGROUND AND OBJECTIVES: Trend analysis reveals that Klebsiella pneumoniae has witnessed a steep enhancement in the antibiotic resistance and virulence over the last few decades. The present investigation aimed at a comprehensive approach investigating antibiotic susceptibility including, extended spectrum beta-lactamase (ESBL) and AmpC ß-lactamase (AmpC) resistance and the prevalence of virulence genes among the K. pneumoniae isolates. MATERIALS AND METHODS: Sixty-one K. pneumoniae isolates were obtained from various clinical infections. Antimicrobial susceptibility was performed by disk diffusion method. The Mast® D68C test detected the presence of ESBLs and AmpCs phenotypically, and later presence of ESBL and AmpC genes was observed by polymerase chain reaction (PCR). Multiplex-PCR was performed to investigate various virulence genes. RESULTS: Amongst 61 K. pneumoniae isolates, 59% were observed as ESBL and 14.7% as AmpC producers. All ESBL producers were positive for bla CTX-M-15 , while bla CTX-M-14 was observed in 54.1% isolates. The frequency of AmpC genes was as follows: bla CMY-2 (60.7%) and bla DHA-1 (34.4%). The most frequent virulence genes were those encoding enterobactin and lipopolysaccharide. Presence of mrkD was associated with bla DHA-1 gene, while bla CMY-2 significantly (p≤0.05) correlated with the presence of iutA and rmpA virulence genes. bla DHA-1 positive isolates had urine as a significant source, while bla CMY-2 positive isolates were mainly collected from wound exudates (p≤0.05). CONCLUSION: Our results highlight that ESBL and AmpC production along with a plethora of virulence trait on K. pneumoniae should be adequately considered to assess its pathogenesis and antibiotic resistance.