Bacterial Treatment Failure Research Articles

Battling Biofilm Forming Nosocomial Pathogens Using Chitosan and Pluronic F127

Biofilm represents a potential strut in bacterial treatment failure. It has a dual action; it affords microbial resistance against antibiotics and facilitate transmission of pathogenic bacteria. Nosocomial bacteria pose a serious problem in healthcare units; it prolongs patient hospital stay and increases the mortality rates beside other awful economical effect. This study was planned for targeting nosocomial bacterial biofilm using natural and biologically safe compounds like Chitosan and/or Pluronic F127. Ninety-five isolates were recovered from 107 nosocomial clinical samples. Different bacterial and fungal species were detected, from which Klebsiella pneumonia (23%), Pseudomonas aeruginosa (19%), Acinetobacter baumannii (18%) and E.coli (17%) were the predominate organisms. Pseudomonas aeruginosa, Acinetobacter baumanni and Klebsiella pneumonia were the abundant antibiotic resistant strains with multi-resistance pattern of 72%, 65% and 59%, respectively. A significant percentage of these isolates were strong biofilm forming. Herein, we investigate the effect of Chitosan and Pluronic F127 alone and in combination with each other against biofilm production. Chitosan show variable degree of biofilm inhibition, while Pluronic F127 was able to retard biofilm formation by 80% to 90% in most strain. There is no significant difference (P< 0.05) between Pluronic F127 alone and its effect in combination with Chitosan.

Lack of penicillin tolerance in group A streptococci.

In acute tonsillitis, group A streptococci (GAS) is the etiological agent in 30–50% of cases. The reported frequencies of clinical and bacterial treatment failure following penicillin therapy range from 10 to 25%, increasing if treatment is reduced from 10 to 7 days. The MIC value of GAS for penicillin V (pcV) is 0.004–0.03 mg/l by the plate dilution and 0.008–0.03 by the broth dilution technique (2). Resistant strains have not been isolated in vivo but according to some investigations, penicillin tolerance may be one cause of treatment failure (6).

Clindamycin in Recurrent Group A Streptococcal Pharyngotonsillitis– An Alternative to Tonsillectomy?

Fifty-three patients with bacterial treatment failure after a 10-day course of treatment with phenoxymethyl penicillin (pcV) for group A streptococcal (GAS) pharyngotonsillitis were randomly assigned to continued treatment with pcV, or to treatment with clindamycin instead. The patients were then followed for 1 year with throat cultures and clinical examination every third month and in the event of symptoms of sore throat. In the first 3-month period, 15/22 patients in the pcV group yielded one or more positive cultures for GAS, all of the same T-type as in the original throat culture, as compared to 3/26 in the clindamycin group (p < 0.001). All three cases in the clindamycin group were due to a new T-type and thus were re-infections. In the pcV group, owing to repeated treatment failure, 12/22 patients were switched to treatment with clindamycin within the 3-month period following the second treatment. During the remainder of the 1-year follow-up period, sporadic cases of GAS-positive throat cultures occurred in both groups, but there was no significant difference in frequency between the two groups. It is concluded that, in patients with GAS pharyngotonsillitis and failure after pcV treatment, a 10-day course of clindamycin can protect the patient from recurrence for at least 3 months and might be an alternative to tonsillectomy.

Penicillin tolerance in group A streptococci and treatment failure in streptococcal tonsillitis.

Penicillin tolerance in Streptococcus pyogenes has been suggested as a possible cause of therapeutic failure in streptococcal phryngitis treated with penicillin. In 144 patients with acute group A streptococcal tonsillitis treated with phenoxymethyl penicillin 12.5 mg per kg body weight b.i.d. for 10 days the same T-type was recovered after treatment in 21%. The recovery rate was higher for non-tolerant strains, 23%, than for tolerant strains, 10% (p greater than 0.05). Of patients with a non-tolerant strain 17% had both clinical and bacterial treatment failure in comparison with 5% infected with a tolerant strain (p greater than 0.05). Reinfection with a new serotype occurred in altogether 3%. The present data did not indicate that penicillin tolerance in group A streptococci is of significance in acute tonsillitis treated with phenoxymethylpenicillin for 10 days.

Treatment failure in acute streptococcal tonsillitis in children over the age of 10 and in adults.

13/169 outpatients (8%) with streptococcal tonsillitis developed a new tonsillitis with the same strain within 2 weeks of completion of therapy (clinical treatment failures) and 24 (14%) remained carriers (bacterial treatment failures) after treatment with phenoxymethylpenicillin (penicillin V) 12.5 mg/kg body weight twice daily for 10 days. The mean serum concentration 60 min after penicillin V administration was 7.84 micrograms/ml. Very large individual differences in serum concentration were found but these differences could not be correlated to treatment failure. About 60% of the patients showed salivary concentrations around 0.03 micrograms/ml. Three strains of streptococci (groups C and G) from patients with bacterial treatment failure had MIC values of 0.06 and 0.12 micrograms/ml. A majority of the patients with clinical treatment failures had contact with individuals with high carrier rates of beta-hemolytic streptococci. It therefore seems likely that some so-called treatment failures in reality are new infections. In clinical treatment failures group A streptococci were twice as common as groups C + G. In bacteriological treatment failures the ratio between A and C + G was 1:1. Patients with nonstreptococcal tonsillitis as well as carriers of groups C and G may appear among bacterial treatment failures.