RESUMO
Respiratory tract infections remain the leading cause of morbidity and mortality worldwide. The burden is further increased by polymicrobial infection or viral and bacterial co-infection, often exacerbating the existing condition. Way back in 1918, high morbidity due to secondary pneumonia caused by bacterial infection was known, and a similar phenomenon was observed during the recent COVID-19 pandemic in which secondary bacterial infection worsens the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) condition. It has been observed that viruses paved the way for subsequent bacterial infection; similarly, bacteria have also been found to aid in viral infection. Viruses elevate bacterial infection by impairing the host's immune response, disrupting epithelial barrier integrity, expression of surface receptors and adhesion proteins, direct binding of virus to bacteria, altering nutritional immunity, and effecting the bacterial biofilm. Similarly, the bacteria enhance viral infection by altering the host's immune response, up-regulation of adhesion proteins, and activation of viral proteins. During co-infection, respiratory bacterial and viral pathogens were found to adapt and co-exist in the airways of their survival and to benefit from each other, i.e., there is a cooperative existence between the two. This review comprehensively reviews the mechanisms involved in the synergistic/cooperativity relationship between viruses and bacteria and their interaction in clinically relevant respiratory infections.
RESUMO
Cyanobacterial species are ancient photodiazotrophs prevalent in freshwater bodies and a natural reservoir of many metabolites (low to high molecular weight) such as non-ribosomal peptides, polyketides, ribosomal peptides, alkaloids, cyanotoxins, and isoprenoids with a well-established bioactivity potential. These metabolites enable cyanobacterial survival in extreme environments such as high salinity, heavy metals, cold, UV-B, etc. Recently, these metabolites are gaining the attention of researchers across the globe because of their tremendous applications as antimicrobial agents. Many reports claim the antimicrobial nature of these metabolites; unfortunately, the mode of action of such metabolites is not well understood and/or known limited. Henceforth, this review focuses on the properties and potential application, also critically highlighting the possible mechanism of action of these metabolites to offer further translational research. The review also aims to provide a comprehensive insight into current gaps in research on cyanobacterial biology as antimicrobials and hopes to shed light on the importance of continuing research on cyanobacteria metabolites in the search for novel antimicrobials.
RESUMO
The diversity of antibiotic-resistance bacteria (ARB) from the effluents of Aizawl city municipal waste dumping site was studied using a culture-dependent method. The present study molecularly identified 73 isolates that were differentiated into three phyla (Proteobacteria, Actinobacteria, and Firmicutes) belonging to 17 family and 22 genera. Bacillus constitutes the most dominant genus comprising 16% of the total isolates. The topology of the phylogenetic tree differentiates them into five major clades. Corynebacterium and Rhodococcus which are morphologically alike were clustered together and the Gram-positive bacteria such as Staphylococcus, Bacillus, and Lysinibacillus formed a separate cluster. Antibiotic resistance of the identified bacterial isolates was performed using 19 different antibiotics. Among the isolates, 70 of them found resistant to polymixin B and nalidixic acid and 10 isolates exhibited resistance to 15 tested antibiotics. The present study revealed that bacteria with antibiotic resistance are extensively distributed in the effluents of the dumping site and may serve as a significant reservoir for the spreading of antibiotic resistance to opportunistic pathogens.
