Article Figures & Data
Figures
- FIG. 1.
PCR-based genotypes of H. influenzae. Lane 1, P6 gene encoding outer membrane protein P6; lane 2, bla; lane 3, pbp3-S; lane 4, pbp3-BLN; lane *, cps b encoding type b capsular polysaccharides. MM, molecular weight marker.
- FIG. 2.
Genetic identity and/or high relatedness among BLNAR isolates. PFGE dendrogram (unweighted pair group method with arithmetic means) of 61 BLNAR strains (MIC ≥ 4 μg/ml). Dice coefficients are shown above the dendrogram. Isolates with ≥80% relatedness on the dendrogram are considered highly genetically related.
Tables
- TABLE 1.
Oligonucleotide primers used in this study
Primer Gene Sequence Product size (bp) PBP3-S ftsI Forward 5′-GATACTACGTCCTTTAAATTAAG-3′ 551 Reverse 5′-GCAGTAAATGCCACATACTTA-3′ PBP3-BLN ftsI Forward 5′-TTCAAGTAACCGTGGTGTGAC-3′ 465 Reverse 5′-GCAGTAAATGCCACATATTTC-3′ BLP bla Forward 5′-TAAGAGAATTATGCAGTGCTGCC-3′ 458 Reverse 5′-TCCATAGTTGCCTGACTCCCC-3′ P6 p6 Forward 5′-ACGATGCTGCAGGCAATGGT-3′ 198 Reverse 5′-TCCATAGTTGCCTGACTCCCC-3′ CPSB cps b Forward 5′-ACGATGCGCAGGCAATGGT-3′ 224 Reverse 5′-CATCAGTATTACCTTCTACTAAT-3′ - TABLE 2.
Sources of clinical isolates of H. influenzae
Characteristic Total no. (%) of isolates No. (%) with susceptibility to AMP P valuea Susceptible Intermediate Resistant Total 264 161 (61.0) 37 (14.0) 66 (25.0) Gender Male 143 (54.2) 91 (63.6) 16 (11.2) 36 (25.2) NS Female 121 (45.8) 70 (57.9) 21 (17.4) 30 (24.8) Age (yr) 0-2 108 (40.9) 56 (51.9) 19 (17.6) 33 (30.6) NS 3-5 38 (14.4) 27 (71.1) 5 (13.2) 6 (15.8) NS 6-12 19 (7.2) 12 (63.2) 1 (5.3) 6 (31.6) NS 13-20 15 (5.7) 10 (66.7) 1 (6.7) 4 (26.7) NS 21-50 72 (27.3) 48 (66.7) 9 (12.5) 15 (20.8) NS ≥51 12 (4.5) 8 (66.7) 2 (16.7) 2 (16.7) NS Specimens type Middle ear fluid 66 (25.0) 34 (51.5) 14 (21.2) 18 (27.3) Nasopharyngeal secretion 77 (29.2) 46 (59.7) 10 (13.0) 21 (27.3) NS Nasal discharge/sinus aspirate 63 (23.9) 38 (60.3) 9 (14.3) 16 (25.4) NS Tonsil swab 58 (22.0) 43 (74.1) 4 (6.9) 7 (19.0) NS Type of clinic University medical center 37 (14.0) 23 (62.2) 7 (18.9) 11 (18.9) NS General hospital 84 (31.8) 49 (58.3) 14 (16.7) 21 (25.0) NS Private clinic 143 (54.2) 89 (62.2) 16 (11.2) 38 (26.6) NS ↵a NS, nonsignificant.
- TABLE 3.
Correlation between PCR-based genotyping and susceptibility to AMP
PCR-based genotype No. of isolates No. of isolates with MIC to AMP (μg/ml) of: MIC (μg/ml) Susceptibility (%)a ≤0.12 0.25 0.5 1 2 4 8 16 32 ≥64 MIC50 MIC90 Range S I R gBLNAS 87 3 35 46 3 0.5 0.5 0.12-1 100 0 0 Group I/II gBLNAR 98 5 23 21 18 23 6 2 0.5 2 0.12-8 68.4 23.5 8.1 Group III gBLNAR 74 7 14 18 24 10 1 4 16 1-32 9.5 18.9 71.6 Group I/II gBLPACR 1 1 128 128 128 0 0 100 Group III gBLPACR 2 2 >128 >128 >128 0 0 100 gBLPAR 2 2 64 >128 64->128 0 0 100 Total 264 8 58 67 28 37 24 26 10 1 5 0.5 8 0.12->128 ↵a S, susceptible; I, intermediate; R, resistant.
- TABLE 4.
Antimicrobial susceptibilities of H. influenzae isolates to other antibiotics according to PCR-based genotypes
Antimicrobial agent PCR-based genotype No. of isolates MIC (μg/ml) Susceptibility (%)a MIC50 MIC90 Range S I R Clavulanate-amoxicillin gBLNAS 87 0.5 1 0.25-2 100 0 0 Group I/II gBLNAR 98 1 4 0.25-16 92.9 NA 7.1 Group III gBLNAR 74 8 32 2-32 26.7 NA 73.3 Total 259 1 16 0.25-32 Cefpodoxime gBLNAS 87 0.12 0.12 ≤0.06-0.12 100 NA 0 Group I/II gBLNAR 98 0.25 2 ≤0.06-8 90.8 NA 9.2 Group III gBLNAR 74 8 16 ≤0.06-64 9.1 NA 91.9 Total 259 0.25 8 ≤0.06-64 Cefditoren gBLNAS 87 ≤0.06 ≤0.06 ≤0.06-0.12 NA NA NA Group I/II gBLNAR 98 ≤0.06 0.12 ≤0.06-0.5 NA NA NA Group III gBLNAR 74 0.25 0.5 ≤0.06-8 NA NA NA Total 259 ≤0.06 0.5 ≤0.06-8 Cefuroxime gBLNAS 87 1 2 0.25-16 97.7 1.1 1.2 Group I/II gBLNAR 98 2 16 0.25-64 66.3 12.3 21.4 Group III gBLNAR 74 64 128 0.25->128 1.4 4.1 94.6 Total 259 2 128 0.12->128 Clarithromycin gBLNAS 87 8 16 2-32 79.3 17.2 3.5 Group I/II gBLNAR 98 8 16 2-32 75.5 22.5 2.0 Group III gBLNAR 74 8 16 4-16 60.8 39.2 0 Total 259 8 16 2-32 Azithromycin gBLNAS 87 2 4 0.25-8 98.8 NA 1.2 Group I/II gBLNAR 98 2 4 0.5-16 95.9 NA 4.1 Group III gBLNAR 74 2 4 0.5-8 97.3 NA 2.7 Total 259 2 4 0.25-16 Telithromycin gBLNAS 87 2 4 0.5-8 97.7 2.3 0 Group I/II gBLNAR 98 2 4 0.5-8 93.9 6.1 0 Group III gBLNAR 74 2 4 1-8 87.8 12.2 0 Total 259 2 4 0.5-8 Levofloxacin gBLNAS 87 ≤0.06 ≤0.06 ≤0.06 100 0 0 Group I/II gBLNAR 98 ≤0.06 ≤0.06 ≤0.06-0.12 100 0 0 Group III gBLNAR 74 ≤0.06 ≤0.06 ≤0.06-0.5 100 0 0 Total 259 ≤0.06 ≤0.06 ≤0.06-0.5 Meropenem gBLNAS 87 ≤0.06 ≤0.06 ≤0.06-0.12 100 0 0 Group I/II gBLNAR 98 0.12 0.25 ≤0.06-0.5 100 0 0 Group III gBLNAR 74 0.25 0.5 ≤0.06-2 90.5 0 9.5 Total 259 0.12 0.5 ≤0.06-2 ↵a S, susceptible; I, intermediate; R, resistant; NA, not available.
