Antimicrobial Resistance in Haemophilus influenzae Respiratory Tract Isolates in Korea: Results of a Nationwide Acute Respiratory Infections Surveillance

Abstract

Antimicrobial susceptibility patterns and ␤-lactam resistance mechanisms of 544 Haemophilus influenzae isolates through the nationwide Acute Respiratory Infections Surveillance (ARIS) network in Korea during 2005 and 2006 were determined. Resistance to ampicillin was 58.5%, followed by resistance to cefuroxime (23.3%), clarithromycin (18.7%), cefaclor (17.0%), amoxicillin-clavulanate (10.4%), and chloramphenicol (8.1%). Levofloxacin and cefotaxime were the most active agents tested in this study. ␤-Lactamase production (52.4%) was the main mechanism of ampicillin resistance, affecting 96.1% of TEM-1-type ␤-lactamase. According to their ␤-lactam resistance mechanisms, all isolates were classified into the following groups: ␤-lactamase-negative, ampicillin-sensitive (BLNAS) strains (n ‫؍‬ 224; 41.5%); ␤-lactamase-positive, ampicillin-resistant (BLPAR) strains (n ‫؍‬ 255; 47.2%); ␤-lactamase-negative, ampicillin-resistant (BLNAR) strains (n ‫؍‬ 33; 6.1%); and ␤-lactamase-positive, amoxicillin-clavulanate-resistant (BLPACR) strains (n ‫؍‬ 28; 5.2%). Among the BLNAR and BLPACR strains, there were various patterns of multiple-amino-acid substitutions in penicillin-binding protein 3. Particularly, among BLNAR, group III isolates, which had three simultaneous substitutions (Met377Ile, Ser385Thr, and Leu389Phe), were identified for the first time in Korea. Three group III strains displayed the highest MIC of cefotaxime (1 to 2 g/ml). The results indicate the importance of monitoring a changing situation pertaining to the increase and spread of BLNAR and BLPACR strains of H. influenzae for appropriate antibiotic therapy for patients with respiratory tract infections in Korea.

Genetic Diversity of theftsIGene in β-Lactamase-Nonproducing Ampicillin-Resistant and β-Lactamase-Producing Amoxicillin-/Clavulanic Acid-Resistant NasopharyngealHaemophilus influenzaeStrains Isolated from Children in South Korea

“…Compared with the report by Kim et al, 18 the proportion of IIa strains was markedly lower, and IIb strains were more prevalent in the nasopharyngeal BLNAR and BLPACR isolates (Table 1). However, the prevalence of IIb was similar to that noted by Bae et al 1 The most prevalent types of both BLNAR and BLPACR strains were also reported to be the most prevalent in a recent Portuguese study by Barbosa et al 2 (Table 1). The ftsI mutation groups of the BLPACR strains exhibited lower diversity than did those of the BLNAR strains, likely because the group of BLPACR strains originated from a small number of types (IIb and III) ( Table 1).…”

“…Previous studies in South Korea showed that BLPAR strains were the most prevalent in the clinical setting, with BLNAR or BLPACR strains accounting for a smaller proportion. 1,18,19 However, in this study, both the prevalence of colonizing NTHi (34.2%) and rates of resistance (73.8%) were very high in the nasopharynx of hospitalized children with no infection history.…”

“…BLNAR strains are usually classified into three groups (I, II, and III) based on the presence of different amino acid substitutions in the transpeptidase region of PBP3, as previously described by Ubukata et al 35 Group II was further divided into subgroups IIa, IIb, IIc, and IId, as described by Dabernat et al,5 and III-like was further classified according to García-Cobos et al 10 Although other classifications exist, for example, that of Hasegawa et al, 12 the former classifications seem to be more convenient for our comparison of the amino acid substitution groups of nasopharyngeal strains to groups derived from infectious strains reported by Bae et al 1 and Kim et al 18 More groups (19 groups) were found in these nasopharyngeal strains compared with the 14 groups noted by Kim et al 18 and 11 by Bae et al 1 in the clinical setting. Compared with the report by Kim et al, 18 the proportion of IIa strains was markedly lower, and IIb strains were more prevalent in the nasopharyngeal BLNAR and BLPACR isolates (Table 1).…”

“…18 Another study of nationwide acute respiratory infection during 2005 and 2006 reported 47.2% BLPAR, 6.1% BLNAR, and 5.2% BLPACR strains among NTHi. 1 Taken together, these findings suggest that BLPAR strains are the most prevalent strains in the clinical setting in Korea, although some differences between studies have been noted. However, there is no information regarding the proportion of nasopharyngeal strains that are BLNAR or BLPACR.…”

Comparative pharmacokinetics of cefuroxime lysine after single intravenous, intraperitoneal, and intramuscular administration to rats

“…A related cephalosporin, cefuroxime sodium, has been listed in the Catalogue of Basic Medicines of the State in China for the treatment of patients with infections of soft tissue, respiratory tract, urinary tract, bone and joint tissues [1][2][3] . With the merits of greater water solubility and reduced irritation to the veins, cefuroxime lysine may become a suitable substitute for cefuroxime sodium in these indications.…”