Graduate Medical Education

University of Pennsylvania Medical Center Guidelines for Antimicrobial Therapy

Streptococcus pneumoniae

Combined Data for the Hospital of the University of Pennsylvania , Presbyterian Medical Center, and the UPHS Outpatient Practices - January 2001 to December 2006

January to December 2001

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	45	73	22	4	131	74	19	7
Penicillin - CDC criteria	45	96	4	0	131	93	7	0
Ceftriaxone	44	100	0	0	49	98	2	0
Levofloxacin	44	100	0	0	129	99	0	1
Erythromycin	44	93	0	7	131	79	2	19
Cotrimoxazole (Sulfa-TMP)	44	74	10	17	130	76	3	21
Chloramphenicol	44	100	0	0	44	73	0	27
Vancomycin	17	100	0	0	44	100	0	0

January to December 2002

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	39	82	13	5	102	77	13	10
Penicillin - CDC criteria	39	95	3	2	102	90	9	1
Ceftriaxone	39	95	3	2	31	84	13	3
Levofloxacin	39	100	0	0	101	93	3	4
Erythromycin	39	89	0	11	102	82	1	17
Cotrimoxazole (Sulfa-TMP)	39	79	3	18	102	75	5	20
Chloramphenicol	10	90	0	10	27	78	0	22
Vancomycin	11	100	0	0	29	100	0	0

January to December 2003

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	48	83	13	4	107	67**	23	9
Penicillin - CDC criteria	48	96	2	2	107	88	8	4
Ceftriaxone	48	98	2	0	46	94	6	0
Levofloxacin	48	100*	0	0	104	98#	0	2
Erythromycin	48	83	0	17	104	78	1	21
Cotrimoxazole (Sulfa-TMP)	48	83	2	15	104	83	6	11
Chloramphenicol	10	80	0	20	39	95	0	5
Vancomycin	16	100	0	0	47	100	0	0

* 16/48 sensitive isolates had levofloxacin MICs >1 and <=2; of these 3 isolates had MICs =2; # 32/102 sensitive isolates had levofloxacin MICs >1 and <=2; of these, 10 had levofloxacin MICs =2

pneumococci with levofloxacin MICs =2 are very likely to have 1st step QRDR mutations; those with MICs = 1.5 are considered by most to be classified in the MIC=2 group.

** 3/3 csf isolates had penicillin MICs <0.05

January to December 2004

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	30	87	10	3	97	63	26	11
Penicillin - CDC criteria	30	94	0	6	97	89	7	4
Ceftriaxone	29	100	0	0	43	95	5	0
Levofloxacin	30	100+	0	0	97	94++	3	3
Erythromycin	30	97	0	3	97	75	0	23*
Cotrimoxazole (Sulfa-TMP)	30	90	7	3	97	81	1	18**
Chloramphenicol	14	100	0	0	42	98	0	2
Vancomycin	16	100	0	0	43	100	0	0

+10/30 susceptible isolates had levofloxacin MIC=2. ++ 32/97 susceptible isolates had MIC=2. Pneumococci with levofloxacin MICs =2 are very likely to have 1st step QRDR mutations.

* most erythromycin resistant strains were from HUP inpatients & outpatients. 27% of HUP isolates were erythro-R vs. 13% of PMC and outreach isolates (p=0.20 by Fisher exact); most SXT resistant strains were also from HUP, with 23% of hup isolates being resistant vs. 10% of PMC and outreach isolates (Fisher test= 0.17).

January to December 2005

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	46	85	4	9	126	61	22	17
Penicillin - CDC criteria	46	91	2	4	126	83	9	8
Ceftriaxone	46	98	2	0	64	87	11	2
Levofloxacin	46	100+	0	0	126	98++	1	1
Erythromycin	46	87	2	11	126	66	2	32
Cotrimoxazole (Sulfa-TMP)	31	89	2	9	126	79	1	21
Chloramphenicol	10	90	10	0	61	95	0	5
Vancomycin	7	100	0	0	61	100	0	0

+2/46 susceptible isolates had levofloxacin MIC=2. ++ 5/126 susceptible isolates had MIC=2. Pneumococci with levofloxacin MICs =2 are very likely to have 1st step QRDR mutations.

January to December 2006

%
	Blood				Non-blood
	n	S	I	R	n	S	I	R
Penicillin -NCCLS criteria	43	70	23	7	93	61	24	15
Penicillin - CDC criteria	43	93	7	0	93	85	8	7
Ceftriaxone	43	93	7	0	46	74	13	13
Levofloxacin	43	100+	0	0	89	99++	1	0
Erythromycin	43	74	0	26	90	63	0	37
Cotrimoxazole (Sulfa-TMP)	43	86	0	14	90	83	4	13
Chloramphenicol	28	96	0	4	44	93	0	7
Vancomycin	27	100	0	0	46	100	0	0

+8/43 susceptible isolates had levofloxacin MIC=2. ++ 22/88 susceptible isolates had MIC=2. Pneumococci with levofloxacin MICs =2 are very likely to have 1st step QRDR mutations.

CLSI Guidelines for Penicillin Susceptibility for Pneumonia 2001-2007 - note that there was a major change in the penicillin G breakpoint in 2008

Susceptible: less than or equal to 0.06 ug/ml

Intermediate: 0.12-1.0 ug/ml

Resistant: >=2

Isolates that are susceptible to penicillin can be considered susceptible to ampicillin, amoxicillin, amoxicillin/clavulanate, ampicillin/sulbactam, cefepime, cefotaxime, ceftriaxone, and imipenem for approved indications.

High doses of intravenous penicillins (e.g. 2 million units q4h in adults with normal renal function) or similarly ampicillin (2 g q6h) are effective in treating pneumococcal pneumonia due to strains in the intermediate category. The 2008 meningitis criteria are the same as the old criteria.

Proposed CDC/Drug Resistant Streptococcus pneumoniae Therapeutic Working Group - for pneumonia only

Susceptible: less than or equal to 1 ug/ml

Intermediate: 2 ug/ml

Resistant: >2 ug/ml

Good evidence exists that for pneumococcal strains with penicillin MICs up to 1 ug/ml, there is no significant difference in outcome between patients with pneumonia infected with susceptible or intermediate MICs. Heffelfinger et al. Arch Intern Med 160: 1399-1408, 2001 . Also for an excellent review of the issue of appropriate MIC breakpoints for pneumococcus, see Musher and Bartlett. Arch Intern Med 161;2538-44

CLSI Breakpoints for Drugs other Than Penicillin
	S	I	R
Levofloxacin	<=2	4	>=8
Ceftriaxone	<=1	2	>=4
Chloramphenicol	<=4		>=8
Erythromycin	<=0.25	0.5	>=1
Cotrimoxazole	<=0.5/9.5	1/19.-2/38	>=4/76
Vancomycin	<=1

View Inpatient Susceptibility Results

Current year pneumococcal susceptibility data

updated 2/7/08 P. Edelstein