Aislamiento de Staphylococcus epidermidis portador de integrón clase 1 en un paciente con sepsis neonatal

Genotyping and high flux sequencing of the bacterial pathogenic elements - integrons

Regarded as a common genetic element responsible for horizontal gene transfer and wide spread of antimicrobial resistance among a large variety of bacteria, integrons are commonly distributed and considered as a determinant in the acquisition and evolution of virulence and antibiotic resistance. To date, the surveillances of integrons have been widely conducted in clinic, community even husbandry. For exact and accurate integron screening, as well as resistant cassettes, reliable monitoring methods is need. Current methods applied on integron screening are mainly conducted by the screening of integrases, followed by the detection of various gene cassettes inserted into integrons. PCR and PCR-related methods (such as RFLP) are mainly employed under such circumstances. Matured LAMP and Sequencing technology have lowered cost and dramatically increased throughput in integron screening and possessed the advantages in similarity analysis of mutated resistant cassettes. This review focused on the classification and characterization of integrons, antimicrobial resistance of integron and genotyping methods for integrons. In methodology, PCR, LAMP and Sequencing technology were mainly introduced for the screening of various classes' integrons and the detection of resistant gene cassettes. Staphylococcus, Pseudomonas and Enterococcus were selected as typical integron-positive clinical and environmental pathogens screened with three methods mentioned above. With the surveillance of the occurrence of integron and resistance gene cassettes conducted in South China, the review also summarized the occurrence, pathogenicity and virulence mediated by integrons.

Microbial pathogenicity and virulence mediated by integrons on Gram-positive microorganisms

Gram-positive microorganisms are one of leading pathogenic microorganisms in public health, including several typical "Super Bugs" as methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae carbapenemase and vancomycin-resistant enterococci, which caused a increasement of infections, clinical failures and expenses. Regarded as a common genetic element responsible for horizontal gene transfer, integrons are widely distributed in various pathogens considered as a determinant in the acquisition and evolution of antibiotic resistance. Current investigations mainly focus on the distribution of integrons in Gram-negative microorganisms, while the role of integron in antibiotic resistance among Gram-positive microorganisms remains unclear and need investigation. To date, the surveillances of integrons in Gram-positive microorganism have been widely conducted in clinic, community even husbandry. China remains one of the worst country in antibiotics abuse worldwide and considered as a potential area for the prevalence of antimicrobial microorganisms and the occurrence of various 'Super Bugs'. Recently, the surveillance of the occurrence of integron and resistance gene cassettes was conducted in South China during the first 10 years of the 21st century. Referred to the surveillance in South China and other investigation in Asian countries, this review aims to summarize the occurrence, pathogenicity and virulence mediated by integrons in typical Gram-positive microorganisms (Staphylococcus, Enterococcus, Corynebacterium and Streptococcus) and the role of integrons in antibiotic resistance.

Resistance integrons: class 1, 2 and 3 integrons

As recently indiscriminate abuse of existing antibiotics in both clinical and veterinary treatment leads to proliferation of antibiotic resistance in microbes and poses a dilemma for the future treatment of such bacterial infection, antimicrobial resistance has been considered to be one of the currently leading concerns in global public health, and reported to widely spread and extended to a large variety of microorganisms. In China, as one of the currently worst areas for antibiotics abuse, the annual prescription of antibiotics, including both clinical and veterinary treatment, has approaching 140 gram per person and been roughly estimated to be 10 times higher than that in the United Kingdom, which is considered to be a potential area for the emergence of “Super Bugs”. Based on the integrons surveillance in Guangzhou, China in the past decade, this review thus aimed at summarizing the role of integrons in the perspective of both clinical setting and environment, with the focus on the occurrence and prevalence of class 1, 2 and 3 integrons.