Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects.

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, ß-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 µg/mL) and antibacterial effects on S. intermedius and ß-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and ß-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against ß-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

Salmonellosis: A food borne zoonotic and public health disease in Egypt.

Salmonellosis is an important food borne disease of public health significance. Global estimates of the disease burden shows more than 20 million cases and 0.15 million deaths annually. The disease caused by a variety of Salmonella organisms worldwide. Salmonella pathogens are belonging to family Enterobacteriaceae that are known to infect many hosts inducing variable clinical diseases pictures. Typhoidal and non-typhoidal Salmonellae are common diseases among Egyptians with severe socioeconomic losses. Different species of animals and poultry as well as their products are the main sources and reservoirs for zoonotic human illness. Enteric fever and gastroenteritis are the main clinical manifestations in patients. Great attention toward salmonellosis drug resistance, prevention and control should be considered.

Synergistic Effect of a Pleuromutilin Derivative with Tetracycline against Streptococcus suis In Vitro and in the Neutropenic Thigh Infection Model.

Tetracycline (TET) has been widely used in the treatment of Streptococcus suis (S. suis) infection. However, it was found that the efficacy of many antibiotics in S. suis decreased significantly, especially tetracycline. In this study, GML-12 (a novel pleuromutilin derivative) was used in combination with TET against 12 S. suis isolates. In the checkerboard assay, the TET/GML-12 combination exhibited synergistic and additive effects against S. suis isolates (n = 12). In vitro time-killing assays and in vivo therapeutic experiments were used to confirm the synergistic effect of the TET/GML-12 combination against S. suis strains screened based on an FICI ≤ 0.5. In time-killing assays, the TET/GML-12 combination showed a synergistic effect or an additive effect against three isolates with a bacterial reduction of over 2.4-log10 CFU/mL compared with the most active monotherapy. Additionally, the TET/GML-12 combination displayed potent antimicrobial activity against four isolates in a mouse thigh infection model. These results suggest that the TET/GML-12 combination may be a potential therapeutic strategy for S. suis infection.

The Virulence Potential of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Cultured from the Airways of Cystic Fibrosis Patients.

Staphylococcus aureus is one of the most common pathogens that infects the airways of patients with cystic fibrosis (CF) and contributes to respiratory failure. Recently, livestock-associated methicillin-resistant S. aureus (LA-MRSA), usually cultured in farm animals, were detected in CF airways. Although some of these strains are able to establish severe infections in humans, there is limited knowledge about the role of LA-MRSA virulence in CF lung disease. To address this issue, we analyzed LA-MRSA, hospital-associated (HA-) MRSA and methicillin-susceptible S.aureus (MSSA) clinical isolates recovered early in the course of airway infection and several years after persistence in this hostile environment from pulmonary specimens of nine CF patients regarding important virulence traits such as their hemolytic activity, biofilm formation, invasion in airway epithelial cells, cytotoxicity, and antibiotic susceptibility. We detected that CF LA-MRSA isolates were resistant to tetracycline, more hemolytic and cytotoxic than HA-MRSA, and more invasive than MSSA. Despite the residence in the animal host, LA-MRSA still represent a serious threat to humans, as such clones possess a virulence potential similar or even higher than that of HA-MRSA. Furthermore, we confirmed that S. aureus individually adapts to the airways of CF patients, which eventually impedes the success of antistaphylococcal therapy of airway infections in CF.

Pet-related Pasteurella multocida induced peritonitis in peritoneal dialysis: a case report and review of the literatures.

BACKGROUND: P. multocida (Pasteurella multocida) is animal-sourced gram-negative coccobacillus which can be transmitted to human through many animals including household pets. P. multocida induced peritoneal dialysis-related peritonitis has rarely been reported. In recent years, there has been an increase in the incidence of P. multocida induced peritoneal dialysis-related peritonitis, for the reason that patients with PD at home bred household pets. In this study, we present a case of a P. multocida induced peritoneal dialysis-related peritonitis, which is suspected to be caused through intimate contact with a household cat and we have reviewed 28 cases reported before and give suggestions for treatment and the way of prevention. CASE PRESENTATION: A 75-year-old man with end-stage renal disease (ESRD) for nearly 5 years on continuous ambulatory peritoneal dialysis (CAPD) was admitted to the nephrology department with a 1-week history of abdominal pain and a cloudy peritoneal dialysis effluent. Based on the history, physical examination and laboratory results with the findings in the peritoneal dialysis fluid, a diagnosis of peritoneal dialysis-related peritonitis was confirmed. The final culture of initial peritoneal effluent results indicated the organism was P. multocida. After a 12-day antibiotic treatment, the condition of patient was not improved. The patient was switched to ampicillin/sulbactam (3 g intravenously) twice every day and the condition was improved significantly. On further inquiring, the patient reported that he had had a cat at home and when the patient did CAPD, the cat was usually playing with the tubing or contacting the patient during CAPD. CONCLUSION: In our case and reviewed cases, P. multocida induced peritoneal dialysis-related peritonitis could be cured by proper antibiotic treatment. If individuals keep the pet away from the PD process, the infection route may be severed. P. multocida induced peritoneal dialysis-related peritonitis does not need catheter removal and exchange with hemodialysis except long-time intractable peritonitis.

The first report of Brucella melitensis Rev.1 human brucellosis in Bosnia and Herzegovina.

Brucellosis is an emergent and endemic zoonotic disease in Bosnia and Herzegovina. In this report we have diagnosed the first case of human brucellosis in Bosnia and Herzegovina, using molecular and microbiological tests, caused by live attenuated Brucella melitensis Rev.1 strain. The infection was caused through unintentional exposure to vaccination of small ruminants in Bosnia and Herzegovina and without any prior accidental self-injection of vaccine suspension.