RESUMO
Skin and soft tissue infections (SSTIs), which are mainly caused by Gram-positive cocci existing on the skin surface, are more common than those caused by Gram-negative bacteria; however, the role of Gram-negative bacteria as emerging pathogens in SSTIs cannot to be ignored. Klebsiella pneumoniae is an opportunistic pathogenic bacterium that mainly inhabits the respiratory and intestinal tracts of humans and animals, as well as the environment, including aquaculture farms. This bacterium can cause multiple infections in humans and animals. The present study reports the case of a SSTI which was suspected to be caused by Klebsiella pneumoniae in a 74-year-old farmer with venous thrombosis. The patient had exposed his four bare limbs to the farmed shrimps and shrimp pond routinely. Pustule and skin ulcers were observed on both the legs of the patient. After receiving anti-infection therapy, the SSTI was almost completely resolved on day 9 and the patient was then discharged.
RESUMO
The improper usage of antibiotics is known to cause widespread antibiotic resistance. In this study, the antibacterial effects of a polypeptide-enriched extract from the skin of the amphibian Rana chensinensis (RCP) were evaluated against the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, the Gram-positive bacterium Staphylococcus aureus and the fungus Candida albicans. The mechanisms underlying these effects were also studied, and the minimum inhibitory concentration of RCP was determined for each species. Analyses of the levels of adenosine triphosphates (ATPases), including Na+/K+-ATPase and Ca2+-ATPase, and scanning electron microscopy confirmed that RCP damaged the microbial cell walls and membranes. RCP perturbed microbial metabolism and particularly affected the tricarboxylic acid cycle (TCA), suggesting that this agent downregulated the levels of succinate dehydrogenase, malate dehydrogenase and ATPase activity in cells. Furthermore, RCP caused the leakage of genetic material from all four microbial strains. In conclusion, RCP effectively inhibited the growth of Gram-negative and Gram-positive bacteria and a fungal species by disrupting energy metabolic processes.