Helicobacter pylori is a highly prevalent and harmful gastrointestinal pathogen. Antibiotic resistance and biofilm complexity have led to a decrease in the cure rate. Probiotics are considered to be an adjuvant therapy for clinical Helicobacter pylori infections. However, there is no substantial explanation for the adjuvant role of probiotics on H. pylori biofilm. In this study, the effects of probiotics in combination with amoxicillin (AMX) and clarithromycin (CLR) on H. pylori biofilms were explored in vitro for the first time. The minimum inhibitory concentration (MIC) and the fractional inhibitory concentration (FIC) for H. pylori was determined by the microbroth dilution method, and the plate counting method was used to determine the minimum biofilm removal concentration (MBEC) and survival rate for H. pylori biofilm. The biofilm structure was observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), protein and polysaccharide contents in extracellular polymeric substances (EPS) were determined by the Bradford method and the phenol-sulfate method, respectively. The gene expression levels of cagA and vacA were evaluated by real-time qPCR. Among the ten H. pylori strains, the clinical strain 3192 showed the strongest film-forming ability, the 3192 biofilms significantly improved the resistance to AMX and CLR, and AMX and CLR showed antagonistic effects on planktonic 3192 cells. When the Lactobacillus salivarius LN12 cell-free supernatant (CFS) was in combination with AMX and CLR, the 3192 biofilm structure was destroyed to a greater extent than when separately; more biofilm biomass and protein in EPS was decreased; and the downregulation effect of the virulence gene vacA was also greater than that of single use. In this study, we suggest that the addition of LN12 to AMX and CLR may enhance the therapeutic effect of triple therapy, especially for the treatment of H. pylori biofilms.

Helicobacter pylori is a gastrointestinal pathogen with a high infection rate. Probiotics are clinically used as an adjuvant to improve the cure rate and reduce the side effects of antibiotic treatment for H. pylori. This study is the first to explore the effects of a cell-free supernatant of high- or low-dose Lactobacillus salivarius LN12 combined with amoxicillin (AMX) and clarithromycin (CLR) on H. pylori 3192 biofilms in terms of the biofilm biomass, survival rates, biofilm structure, and transcriptome. The results showed that the combination of the CFS of high-dose LN12 with AMX and CLR had stronger effects on the biofilm biomass, survival rate, and structure of H. pylori 3192 biofilms. H. pylori 3192 biofilms may increase the expression of NADH-related genes and downregulate flagellar assembly and quorum sensing-related receptor genes to deal with the stronger stress effects of high-dose LN12 with AMX and CLR. In conclusion, the biofilm biomass, survival rate, structure, and transcriptome results showed that the combination of LN12 CFS with AMX and CLR had dose effects. We recommend that compared with low doses, high doses of L. salivarus LN12 combined with AMX and CLR may be more effective for H. pylori biofilm than low doses.

Here, we present the complete genome sequence of Helicobacter pylori 3192, isolated from a patient diagnosed with nonatrophic gastritis in China. The genome is 1.6 Mbp long and encompasses 1,566 genes, including cagA and vacA genes.

Partial discharges in power cables will generate small currents with low frequencies in the ground cords. In cable PD online monitoring systems, CTs are usually used to obtain such PD signals. In this paper, by derivations based on theories of wave propagation, the frequency characteristics of Rogowski CTs (RCTs) and the effects of transformer parameters (size, core material, etc.) on its pass band B, sensitivity H(jω0), the lower cutoff frequency fL is acquired. The feasibility of such derivations is verified by experiments. By conducting comparative experiments, the effect of the use of screening box and the way of coil winding on the performance of a current transformer is acquired. A feasible plan to improve the frequency characteristics of CTs is presented, in order to acquire more stable gain and better anti-interference ability within their pass band.