PCR and Infectious Diseases

Since the 1950s, the medical community has been faced with infectious diseases, which have brought significant public health and financial challenges. Currently, routine testing for the laboratory diagnosis for infectious agents is based on cell culture, serological, and molecular methods. However, cell culture-based methods are used mainly in research laboratories and are less sensitive methods when compared with serological and molecular methods. The diagnosis of infectious diseases has been revolutionized by the development of molecular techniques, mainly with the applications of polymerase chain reaction (PCR). The high sensitivity, specificity, and ease with which the PCR can be used to detect genetic sequences known have led to your wide application in science. A great number of qualitative and quantitative molecular assays are mostly based on what have been described such as real-time PCR, multiplex PCR, LAMP-PCR, and digital PCR. These assays could identify active infection by detecting infectious agents and nucleic acid in various clinical conditions including arboviruses, sexually transmitted infections, and bacterial infections. Further advancement of molecular technology is needed to improve the capacity to detect infectious agents in order to control the spread of infectious diseases and lead to appropriate actions which help to benefit patients and health-care workers themselves

Microbial content recovered from diabetic foot infections: a cross-sectional study in Brazil / Conteúdo microbiano recuperado em infecções de pé diabético: um estudo transversal no Brasil

In Brazil, the prevalence of diabetes mellitus (DM) is 11.9 million cases. Diabetic foot ulcers (DFU) increase morbidity and cause hospital admissions among DM patients. In an attempt to better understand DFU, this cross-sectional study investigated microbial content and their susceptibility to antimicrobials. Secretion from foot ulcers of 30 diabetic patients were obtained in three Brazilian hospitals and submitted to microbiological evaluation. All recovered strains were identified and submitted to antimicrobial susceptibility tests. Genetic diversity was investigated by PCR coupled with denaturing gradient gel electrophoresis (PCR-DGGE). DFU exhibited a polymicrobial profile composed of 72.5% aerobic and 22.3% anaerobic bacteria, and 2.5% fungi species. A total of 91 microorganisms were isolated, and the number of recovered species per patient ranged from 1-9. Peptostreptococcus spp. was the most frequently recovered obligate anaerobic Genus and was resistant mostly to penicillin and clindamycin. A total of 37.5% S. aureus strains were methicillin resistant. E. coli were the most susceptible Gram-negative species and Pseudomonas aeruginosa were the most resistant. The present study demonstrated that almost 34% of microbial species observed on DGGE gels were not cultivable. The recovery of multidrug resistant microorganisms pointed out to the need for more attention when prescribing an empirical therapy and emphasized the relevance of this study