Related Experiment Videos
Antibiotic resistance study of invasive S.pneumoniae
Abstract:
121 invasive pneumococci isolated from meningitis, septicemia, pneumopathies and other clinical infections (osteo-arthritis, peritonitis, sinusitis, otilis, conjunctivitis, plagues) were screened for susceptibility to penicillin G (P), erythromycim (E), chloramphenicol (Cl), tetracycline (T), ceftriaxone (Cro), and sulfametoxazole trimethoprim (SxT) by diffusimetric method, by MICs to P and Cro by agar dilutions and E-test. 48.8% were penicillin resistant (MICs > 0.12 microgram/ml), 22.7% being highly resistant (MICs 3-8 micrograms/ml). Any strain was resistant to P only, but patterns with P included were frequent (55.8%). Resistance to SxT was highest (monoresistance 25.6% as well as polyresistance 69.8%). 72.9% were resistant strains to > or = 1 antibiotic with 12 patterns of resistance (1-5 antibiotics). All of the strains were susceptible to Cro (MICs-0.003-0.5 microgram/ml). Resistance was closely correlated to serotypes 6,9,14,19,23 to site of isolation and diagnosis. Pneumococci from meningitis were 2-3 times more susceptible to P,E,Cl,T and SxT than the isolates from pneumopathies or other infections.
Insights
Invasive pneumococci show high resistance to penicillin and sulfamethoxazole-trimethoprim, but remain susceptible to ceftriaxone. Resistance patterns varied by serotype and infection site, with meningitis isolates being more susceptible.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Invasive pneumococcal infections pose significant public health challenges.
- Understanding antimicrobial susceptibility patterns is crucial for effective treatment.
Purpose of the Study:
- To evaluate the antimicrobial susceptibility of invasive *Streptococcus pneumoniae* isolates.
- To identify resistance patterns and correlations with serotypes and clinical origins.
Main Methods:
- Disk diffusion, agar dilution, and E-test methods were used.
- Susceptibility testing against penicillin G, erythromycin, chloramphenicol, tetracycline, ceftriaxone, and sulfamethoxazole-trimethoprim.
- Analysis of 121 invasive pneumococcal isolates from various clinical infections.
Main Results:
- 48.8% of isolates were resistant to penicillin G, with 22.7% highly resistant.
- Sulfamethoxazole-trimethoprim exhibited the highest resistance rates (monoresistance 25.6%, polyresistance 69.8%).
- All isolates remained susceptible to ceftriaxone; resistance correlated with specific serotypes and infection sites.
Conclusions:
- Ceftriaxone is a reliable treatment option for invasive pneumococcal infections.
- High rates of penicillin and sulfamethoxazole-trimethoprim resistance necessitate careful antibiotic selection.
- Serotype and clinical origin are important factors influencing pneumococcal resistance patterns.