Aims: Currently, limited antibiotics are available to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. One approach is the use of adjuvants in antibiotic therapy. 1,4-Naphthoquinones are naturally occurring alkaloids shown to have antibacterial properties. The objective of this study is to investigate the synergy between 1,4-naphthoquinone and selected b-lactam antibiotics and to evaluate the potential use of 1,4naphthoquinone as an adjuvant in antibiotic treatment against MRSA infections. Methods: The antibacterial activity of 1,4-naphthoquinone and plumbagin was tested against nine pathogenic bacterial strains using the microdilution broth method. The interactions between 1,4-naphthoquinone and three antibiotics (cefuroxime, cefotaxime, and imipenem) were estimated by calculating the fractional inhibitory concentration of the combination. Results: The compounds 1,4-naphthoquinone and plumbagin exhibited a broad range of bacteriostatic and bactericidal effects against both Gram-positive and Gram-negative bacteria. The interaction between 1,4naphthoquinone and imipenem, cefuroxime, and cefotaxime was synergistic against methicillin-sensitive Staphylococcus aureus and MRSA clinical strains. Against ATCC-cultured MRSA, a synergistic effect was observed between 1,4-naphthoquinone and cefotaxime. However, combination with imipenem only produced an additive effect, and an antagonistic action was observed between 1,4-naphthoquinone and cefuroxime. Conclusions: Although individually less potent than common antibiotics, 1,4-naphthoquinone acts synergistically with imipenem, cefuroxime, and cefotaxime against MRSA clinical strains and could potentially be used in adjuvant-antibiotic therapy against multidrug resistant bacteria.

Epidemiology and etiology of hand, foot, and mouth disease (HFMD) based on large sample size or evaluation of detection for more enterovirus serotypes are not well investigated in Chongqing of China. 45,616 suspect HFMD patients were prospectively enrolled among whom 21,615 were laboratory confirmed HFMD cases over a 5-year period (January 2011 to December 2015). Their epidemiological, clinical, and laboratory data were extracted and stratified by month, age, sex, disease severity, and enterovirus serotype. Subsequently 292 non-EV-A71/CV-A16 HFMD confirmed cases were randomly selected in three consecutive outbreaks to detect CV-A6 and CV-A10, using RT-PCR. Results showed that the HFMD epidemic peaked in early summer and autumn. The median age of onset was 2.45 years with a male-to-female ratio of 1.54:1, and with children under 5 years of age accounting for 92.54% of all confirmed cases. EV-A71 and CV-A16 infection accounted for only 36.05% (7793/21615) of total confirmed cases while EV-A71 accounted for 59.64% (232/389) of severe cases. Importantly, the proportion of EV-A71 infection generally increased with age which showed rapid growth in severe cases. CV-A6 and CV-A10 were tested positive in Chongqing, but CV-A6 had greater positive rates of 62.33% while CV-A10 had 4.79% in non-EV-A71/CV-A16 HFMD confirmed cases.

Background: To evaluate the diagnostic performance of ultrasound-guided percutaneous needle biopsy (US-PNB) for peripheral pulmonary lesions on the basis of the intention-to-diagnose principle and to identify the risk factors for diagnostic failure.