Antibiotic Resistance in Sputum Isolates of Streptococcus pneumoniae in Chronic Obstructive Pulmonary Disease is Related to Antibiotic Exposure

Figures & data

Table 1.  Characteristics of patients with atleast one S. pneumoniae isolate compared with those without any S. pneumoniae isolate from sputum culture.

Characteristic	Patients with an S. pneumoniae isolate	Patients without an S. pneumoniae isolate	P
Number	38	89
Age (Mean ± SD)	66.55 ± 9.82	67.12 ± 9.39	0.76
Male (Percentage)	97.37	98.88	0.51
Race
White (Percentage)	35 (92%)	72 (81%)	0.18
Black (Percentage)	3 (8%)	17 (19%)
Years since COPD diagnosis (Median, Range)	6.5 (0–50)	6.0 (0–54)	0.90
Smoking in pack years (Mean ± SD)	76.16 ± 37.38	81.41 ± 42.71	0.51
FEV1 in Liters (Mean ± SD)	1.56 (0.56–4.07)	1.38 (0.47–3.93)	0.29
FEV1% predicted (Median, Range)	49.0 (17–95)	42.0 (15–99)	0.22
FEV1/FVC % (Mean ± SD)	53.22 ± 11.78	52.89 ±13.75	0.89
Exacerbations per year (Median, Range)	2.0 (0–8.74)	1.95 (0–14.05)	0.95

SD: Standard Deviation;

FEV₁: Forced Expiratory Volume in 1 Second; FVC: Forced Vital Capacity.

Table 2.  Patients with S. pneumoniae isolated from at least one sputum culture.

Patient Number	Total Visits By Patient	Number of Visits (%) S. pneumoniae Isolated	Number of Different Strains
5	54	12 (22.2)	6
6	33	1 (3.0)	1
10	120	3 (2.5)	3
14	49	6 (12.2)	4
19	115	11 (9.6)	2
22	20	6 (30.0)	1
27	57	1 (1.8)	1
31	17	2 (11.8)	1
33	70	3 (4.3)	2
34	11	1 (9.1)	1
42	5	1 (20.0)	1
44	103	14 (13.6)	1
46	115	5 (4.3)	4
48	111	1 (0.9)	1
53	25	1 (4.0)	1
60	57	2 (3.5)	2
63	99	40 (40.4)	2
67	86	9 (10.5)	5
68	83	1 (1.2)	1
70	86	3 (3.5)	2
74	58	17 (29.3)	6
75	78	2 (2.6)	2
76	24	1 (4.2)	1
79	61	1 (1.6)	1
84	56	9 (16.1)	2
87	69	7 (10.1)	2
89	29	1 (3.4)	1
90	5	1 (20.0)	1
96	54	2 (3.7)	1
100	53	3 (5.7)	2
103	41	1 (2.4)	1
105	46	1 (2.2)	1
106	38	4 (10.5)	2
108	27	16 (59.3)	2
116	31	1 (3.2)	1
118	28	1 (3.6)	1
119	30	2 (6.7)	1
121	30	1 (3.3)	1
Total	2074	194 (9.4)	71

Table 3.  Serotypes of S. pneumoniae isolates.

Serotype of S. Pneumoniae	Number of Isolates N = 194
3	15
4	1
7	6
14	2
15	26
16	2
22	1
31	2
34	1
11A	12
18C	3
19F	18
22F/A	2
23/F	1
23A/B	2
23F	52
33F	1
35B	1
6A	6
6B	7
9A/L/N	12
9V	1
NT	20

NT = Non-typeable / Not able to differentiate.

Figure 1.  Effect of exposure to a macrolide antibiotic in previous 3 and 6 months and sputum isolation of macrolide resistant S. pneumoniae in COPD patients.

Table 4.  Antibiotic exposure in the previous 3 and 6 months in patients with the 75 S. pneumoniae isolates included in this analysis.

Type of Antibiotic	Antibiotic use for any reason		Antibiotic Use for COPD Exacerbation
	3 Months	6 Months	3 Months	6 Months
β-lactam	10	16	8	12
Amoxicillin	2	5	1	4
Amoxicillin/Clavulanic acid	7	8	6	6
Ceftriaxone	1	1	1	1
Cefuroxime	0	1	0	0
Ampicillin/Sulbactam	0	1	0	1
Macrolide	11	18	9	14
Clarithromycin	1	1	0	0
Azithromycin	10	17	9	14
Tetracyclines	1	3	0	1
Trimethoprim/Sulfamethoxazole	7	14	2	7
Fluoroquinolones	14	21	11	17
Ciprofloxacin	4	5	3	4
Gatifloxacin	1	1	1	1
Levofloxacin	6	12	6	11
Ofloxacin	4	4	2	2

Table 5.  Exposure to β-lactam, macrolide, or trimethoprim/sulfamethoxazole (TMP Sulfa) in past 3 and 6 months with isolation of S. pneumoniae resistant to those antibiotics from COPD patients

	β-lactam exposure in past 3 months	No β-lactam exposure in past 3 months	p (Fisher's exact test)	β-lactam exposure in past 6 months	No β-lactam exposure in past 6 months	p (Fisher's exact test)
Penicillin Resistance	1 (10%)	5 (7.7%)	0.59	1 (6.2%)	5 (8.5%)	1.00
	Macrolide exposure in past 3 months	No macrolide exposure in past 3 months	p (Fisher's exact test)	Macrolide exposure in past 6 months	No macrolide exposure in past 6 months	p (Fisher's exact test)
Erythromycin Resistance	6 (54.5%)	12 (18.7%)	0.02	10 (53.6%)	8 (14%)	<0.001
	TMP Sulfa exposure in past 3 months	No TMP Sulfa exposure in past 3 months	p (Fisher's exact test)	TMP Sulfa exposure in past 6 months	No TMP Sulfa exposure in past 6 months	p (Fisher's exact test)
Trimethoprim/Sulfamethoxazole Resistance	3 (42.9%)	9 (13.2%)	0.08	3 (21.4%)	9 (14.8%)	0.69

Penicillin resistance was defined as MIC ≥ 2.

Erythromycin resistance was defined as MIC ≥ 1.

Trimethoprim/Sulfamethoxazole resistance was defined as MIC ≥ 4.