Impact of the revised penicillin susceptibility breakpoints forStreptococcus pneumoniaeon antimicrobial resistance rates of meningeal and non-meningeal pneumococcal strains

Abstract

BACKGROUND AND OBJECTIVESIn January 2008, the Clinical Laboratory Standard Institute (CLSI) revised the Streptococcus pneumoniae breakpoints for penicillin to define the susceptibility of meningeal and nonmeningeal isolates. We studied the impact of these changes. In addition, the pneumococcal resistance rate to other antimicrobial agents was reviewed.DESIGN AND SETTINGLaboratory data on peumococcal isolates collected retrospectively from hospitalized children in tertiary care hospital in Riyadh, Saudi Arabia from January 2006 to March 2012.PATIENTS AND METHODSOnly sterile samples were included from cerebrospinal fluids, blood, sterile body fluids and surgical tissue. Other samples such as sputum and non sterile samples were excluded. We included samples from children 14 years old or younger. The minimum inhibitory concentration (MIC) for penicillin, cefuroxime, ceftriaxone and meropenem were determined by using the E-test, while susceptibility to erythromycin, cotrimoxazole and vancomycin were measured using the disc diffusion methods following the guideline of CLSI.RESULTSSpecimens were analyzed in two different periods: from January 2006 to December 2007 and from January 2008 to March 2012. During the two periods there were 208 samples of which 203 were blood samples. Full penicillin resistance was detected in 6.6% in the first period. There was decrease in penicillin nonmeningeal resistance to 1.5% and an increase in resistance in penicillin meningeal 68.2% in the second period (P=.0001). There was an increase in rate of resistance among S pneumoniae isolates over the two periods to parenteral cefuroxime, erythromycin and cotrimoxazole by 34.6%, 35.5% and 51.9%, respectively. Total meropenem resistance found 4.3% and no vancomycin resistance was detected.CONCLUSIONSThe current study supports the use of the revised CLSI susceptibility breakpoints that promote using penicillin to treat nonmeningeal pneumococcal disease, and might slow the development of resistance to broader-spectrum antibiotics.

Streptococcus pneumoniae vaccination strategies and its expected impact on penicillin non-susceptibility in children under the age of five: Let's recap!

“…In order to better comprehend and respond to the global rise of antibiotic non-susceptibility, the World Health Organization (WHO) called for action through its “Global action plan on antimicrobial resistance” that recommends the gathering of key data and information through close monitoring and surveillance of rapidly emerging resistant strains [33] . Likewise, the Clinical Laboratory Standards Institute (CLSI) suggested the use of different sensitivity breakpoints for pneumococcal meningitis (≤0.06 μg / ml) and non-meningitis pneumococcal disease (≥2 μg / ml) for an optimal long-haul reporting of pneumococcal penicillin resistance rates in epidemiological surveillance studies [34] , [35] . Prior to the development of PCV-7, several pneumococcal surveillance sites reported increased resistance rates of pneumococcal serotypes in pediatric populations worldwide [36] , [37] , [38] , [39] .…”

Management of community-acquired pneumonia in infants and children: Clinical practice guidelines endorsed by the Saudi Pediatric Infectious Diseases Society

“…In this report, we provide the most up to date guidelines for the management of community-acquired pneumonia (CAP) in infants and children aged over 90 days. The current recommendations given by the Pediatric Infectious Diseases Society and Infectious Diseases Society of America 2011 Practice guidelines, WHO, and other international guidelines are considered as well as regional variations in susceptibility patterns and resources [[1], [2], [3], [4], [5], [6]]. Some published and unpublished antibiograms from several tertiary care organizations in the regions comprising Saudi Arabia, United Arab Emirates, Kuwait, and Oman have shown significant improvements in the susceptibility pattern of Streptococcus pneumoniae to penicillin for the last three years, so the current recommendations have been customized accordingly [2,3].…”