Study on the possible use of Vi polysaccharide typhoid fever vaccine to control endemic typhoid fever in Nepal

Biofilm formation, antimicrobial susceptibility, serogroups and virulence genes of uropathogenic E. coli isolated from clinical samples in Iran

BACKGROUND

Uropathogenic Escherichia coli O- Serogroups with their virulence factors are the most prevalent causes of UTIs. The present research performed to track common uropathogenic E.coli serogroups, antibiotic resistance pattern of strains and prevalence of virulence genes in isolations having the ability to constitute biofilm.

METHODS

In this research 130 E.coli isolation from patients having UTI symptoms were collected and antimicrobial resistance pattern was performed by Kirby-Bauer method. Polymerase chain reaction was done using primer pairs to identify common serogroups of uropathogenic E.coli and studying virulence genes in isolations creating biofilm.

RESULTS

Among 130 E.coli isolates, 80 (61.53 %) were able to make biofilm that 15 isolates (18.75 %) indicated strong reaction, 20 (25 %) of medium and 45 (56.25 %) of weak biofilm reaction. Among isolations creating biofilm, the highest resistance reported to Ampicillin (87.5 %) and the lowest to Nitrofurantoin (3.75 %). The frequency of fimH, pap, sfa and afa genes in isolations having the ability to create strong biofilm reported 93.33 %, 86.66 %, 86.66 % and 66.66 %, respectively.

CONCLUSIONS

The findings indicated the importance of virulence genes in serogroups producing uropathogenic E.coli biofilm. It is recommended that strains producing biofilm before antibiotic use should be studied.

Anti-inflammatory, analgesic and antipyretic activity of methanolic Tecomaria capensis leaves extract

OBJECTIVE

To evaluate the analgesic, anti-inflammatory and antipyretic activity of methanolic Tecomaria capensis (T. capensis) leaves extract using different models in rats.

METHODS

Methanolic T. capensis leaves extract (100, 300, 1000 and 2000 mg/kg body weight) was given to rats orally to observe acute toxicity, and observed for 14 days. Analgesic activity was evaluated using tail immersion and formalin induced paw licking models in rats. Anti-inflammatory activity was evaluated using carrageenan induced paw edema model in rats. Antipyretic activity was evaluated using brewer's yeast induced pyrexia model in rats. Methanolic T. capensis leaves extract were given at dose of 100, 200 and 500 mg/kg p.o.

RESULTS

Results demonstrated that the no mortality was reported even after 14 days. This indicated that the methanol extract was safe up to a single dose of 2 000 mg/kg body weight. Methanolic T. capensis leaves extract (100, 200 and 500 mg/kg p.o.) significantly increased the latency period in the tail immersion test, reduced the licking time in both the neurogenic and inflammatory phases in the formalin test. Methanolic T. capensis leaves extract (100, 200 and 500 mg/kg p.o.) significantly prevented increase in volume of paw edema. Methanolic T. capensis leaves extract at the doses of (100, 200 and 500 mg/kg p.o.) significantly decreased the rectal temperature of the rats.

CONCLUSIONS

This study exhibites that methanolic T. capensis leaves extract possesses analgesic, anti-inflammatory and antipyretic activity which may be mediated by the central and peripheral mechanisms.

In vitro biofilm formation by uropathogenic Escherichia coli and their antimicrobial susceptibility pattern

OBJECTIVE

To detect in vitro biofilm formation of uropathogenic Escherichia coli (E. coli) (UPEC) strains isolated from urine specimens and also to determine their antimicrobial susceptibility pattern using 13 commonly used antibiotics.

METHODS

The present study comprised of 166 urine specimens collected from tertiary care hospitals in and around Coimbatore, South India. All the specimens were subjected to gram staining, bacterial culture and the E. coli strains were screened for biofilm formation using Tube Method (TM), Congo Red Agar (CRA) and Tissue Culture Plate method (TCP) respectively. Subsequently, the antimicrobial susceptibility test was performed by Kirby Bauer-disk diffusion method for the biofilm and non-biofilm producing E. coli strains.

RESULTS

Of the 100 (60.2 %) E. coli strains, 72 strains displayed a biofilm positive phenotype under the optimized conditions in the Tube Method and the strains were classified as highly positive (17, 23.6%), moderate positive (19, 26.3 %) and weakly positive (36, 50.0 %), similarly under the optimized conditions on Congo Red agar medium, biofilm positive phenotype strains were classified as highly positive (23, 23 %), moderate positive (37, 37 %) and weakly positive (40, 40%). While in TCP method, the biofilm positive phenotype strains were also classified as highly positive (6, 6 %), moderate positive (80, 80 %) and weakly positive (14, 14 %), it didn't not correlate well with the tube method for detecting biofilm formation in E. coli. The rates of antibiotic resistance of biofilm producing E. coli were found to be 100 % for chloramphenicol and amoxyclav (amoxicillin and clavulanic acid), 86% for gentamicin and cefotaxime, 84% for ceftazidime, 83% for cotrimoxazole and piperacillin/tazobactam, 75% for tetracycline and 70% for amikacin.

CONCLUSIONS

This study reveals the prevalence and antimicrobial susceptibility pattern of biofilm and non-biofilm producing uropathogenic E. coli strains.