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Typhoid fever, caused by the human restricted pathogen Salmonella Typhi, remains a major global public health concern. Even after successful treatment, approximately 3-5% of patients with typhoid fail to clear the bacteria within one year and become chronic carriers. Most typhoid carriers have gallstones in their gallbladder, and biofilm formation on gallstones is highly correlated with chronic carriage. This study’s goal was to identify asymptomatic typhoid carriers in an endemic setting in Kenya, and to compare acute versus chronic isolates. A cohort of typhoid fever patients identified through blood and/or stool culture, and their household contacts, were followed up after treatment to detect longitudinal S. Typhi stool shedding. An abdominal ultrasound scan was used to identify individuals with gallstones. A total of 32 index patients and 32 household contacts were successfully followed-up. Gallstones were detected in 4 cases and 1 household contact. The duration of S. Typhi shedding was significantly longer in individuals with gallstones compared to those without, P<0.001. Eighty-three (83) S. Typhi strains were tested for susceptibility to commonly used antimicrobials and examined by in vitro biofilm formation assays. Out of 37 infected individuals, 32.4% had infections caused by multidrug resistant (MDR) S. Typhi strains and only 18.9% were infected by susceptible strains. Non-MDR strains formed significantly better biofilms in vitro than the MDR strains (P<0.001). This study provides data on S. Typhi chronic carriage that will influence public health approaches aimed at reducing typhoid transmission and the burden of infection.
Objectives Bacterial resistance to conventional antibiotics is a serious public health problem. Over the past decade, small proteins known as antimicrobial peptides (AMPs), natural compounds produced by all prokaryotic and eukaryotic cells have shown promising results in overcoming the growing problems of antibiotic resistance. There are nowadays several peptides of plant origin and rich in cysteines which have shown very good antimicrobial activities. The research of molecules with bactericidal activity is always current event with increase of multi resistance. The present study was undertaken to investigate the in vitro antibacterial activities of four synthesized peptides obtained in 97% yield by the solid phase synthesis method. Method The synthesis reaction was monitored by combined HPLC and LCMS methods and evaluation of the antibacterial property of these synthetized peptides. The antibacterial test was perform using micro dilution method on many species of bacteria, S. epidermidis ATCC 35984, S. aureus ATCC 25923, S. aureus ATCC 8095, E. faecalis ATCC 29212, E. faecium ATCC 700221, K. pneumoniae ATCC 700603, E. coli ATCC 25922, A. baumannii ATCC 19606, P. aeruginosa ATCC 27853. Results The conformity and effectiveness of the synthesis of the peptides was carried out by LCMS with an average yield of 91%. Peptides were bactericidal on almost all of these strains excepted E. coli ATCC 25922 where it was bacteriostatic. The biofilm eradication capacity test was carried out on two ATCC strains of S. epidermidis. Strain 35984 is a good biofilm-forming strain, while strain 12228 is considered a poor biofilm former. Comparison of the presence of biofilm between them showed a significant difference with p<0.05, showing that the controls used are significantly different in all cases. Conclusion Antimicrobial peptides are a good alternative today to fight against microbial resistance. In view of the results obtained, the different Neo peptides could serve as a basis for preclinical approaches to potential new active ingredients to combat certain microbial resistance.