Journal of Antimicrobial Chemotherapy (1992) 29, 299-302
Comparative in-vitro activity of four peptide antibiotics against penicillin-resistant Streptococcus pneumoniae isolated from cerebrospinal fluid (CSF) J. L. Rodrfgnez-Tadda, F. L6pez de Felipe, J. V. Martinez-Saarez* and A. FenoD Servicio de Bacteriologia, Centro National de Microbiologia, 28220 Majadahonda, Madrid, Spain
Introduction The prevalence of penicillin-resistant strains of Streptococcus pneumoniae in Spain is among the highest in the world (Fenoll et al., 1991). S. pneumoniae is an important cause of meningitis. Clinical failures of penicillin in the treatment of meningitis caused by intermediate penicillin-resistant pneumococci have been well documented (Klugman, 1990). Many of these penicillin-resistant strains are resistant to multiple drugs including other 0-lactams, erythromycin, clindamycin, tetracycline, chloramphenicol and aminoglycosides (Klugman, 1990; Fenoll et al., 1991). Daptomycin and SKF 104662 are new lipo- and glycopeptide antibiotics which have activity against Gram-positive pathogens similar to that of teicoplanin and vancomycin (Neu, 1988; Jorgensen, Redding & Maher, 1989). The in-vitro activity of these four peptide antibiotics against 43 penicillin-resistant S. pneumoniae recovered from patients with meningitis was studied, and compared with those of 15 other antimicrobial agents. The serotype distribution of these resistant strains was also examined. Methods Bacterial isolates A total of 43 individual clinical isolates of penicillin-resistant S. pneumoniae recovered from CSF were tested for antimicrobial susceptibility (penicillin MIC > 0-06 mg/L). These were all obtained from different patients in hospitals throughout Spain in 1989 and 1990. For comparative purposes, 17 penicillin-susceptible pneumococci (penicillin 'Corresponding author. 299 0305-7453/92/030299 + 04 SOZOO/0
© 1992 The British Society for Antimicrobial Chemotherapy
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
The in-vitro activity of four peptide antibiotics against 43 penicillin-resistant Streptococcus pneumoniae isolated from cerebrospinal fluid (CSF) was evaluated. The activity of SKF104662 was slightly greater to that of vancomycin, teicoplanin and daptomycin (MICs for 90% of the isolates tested 0-06,0-25,0-12 and 0-25 mg/L, respectively) and superior to the other 15 drugs tested. The serotype of these penicillin-resistant strains was also determined. The strains that belonged to the predominant serotype 9 were resistant only to penicillin. All six erythromycin- and clindamydn-resistant strains belonged to serotype 6 and three of them were also resistant to chloramphenicol and tetracydine (plus penicillin).
300
J. L. Rodrigoez-Tudela et al
MIC < 0-06 mg/L) recovered from blood (ten strains), CSF (six strains) or pulmonary biopsy (one strain), were also tested. S. pneumoniae R6, a penicillin-susceptible, nonencapsulated laboratory strain, Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, and Escherichia coli ATCC 25922 were used as controls in all susceptibility tests. Antimicrobial agents
Susceptibility tests Susceptibility tests were performed by an agar dilution technique with Mueller-Hinton agar supplemented with 5% sheep blood. Inocula of as 10* cfu were prepared by appropriate dilutions in a fresh Todd-Hewitt broth of an overnight culture on blood agar, and applied with a 96-prong inoculating device (Microtiter AM80, Denley-tech, England). Thirty-four strains were tested on each duplicated plate, which were incubated overnight at 37°C. The MIC was read as the lowest concentration of antibiotic that prevented visible growth. Serotype determination All strains were serotyped by the Quellung reaction with specific antisera from the Staten Seruminstitut (Copenhagen). Results The peptide antibiotics showed greater in-vitro activity against penicillin-resistant strains than the other drugs tested (Table I). SKF104662 was slightly more active than the other pep tides tested against penicillin-resistant pneumococci. The MIC*, of penicillin G against penicillin-resistant strains (including intermediate and fully resistant isolates) was 2-0 mg/L (Table I). The pneumococci that were penicillin-resistant were not categorically resistant to third-generation cephalosporins and imipenem, but their MIC^s were 1 and 025 mg/L respectively. In this study the most active /J-lactam drugs in-vitro for penicillin-resistant pneumococci were cefotaxime, ceftriaxone and imipenem. Temafloxacin was the most active among the three quinolones tested. We did not detect a significant level of resistance to rifampicin. The MIC^ was ^ 0-12 mg/L, with only one strain with a MIC value above 16 mg/L.
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
The antimicrobial agents studied included the following: benzylpenicillin (Beecham Laboratories), cephalothin (Eli Lilly & Co.), cefuroxime (Glaxo), cefotaxime (HoechstRoussel Pharmaceuticals Inc.), ceftriaxone (Hoffman-La Roche), imipenem (Merck Sharp & Dohme), vancomycin (Eli Lilly & Co.), teicoplanin (Merrell-Dow Research Institute), daptomycin (Eli Lilly & Co.), SKF104662 (Smith O n e & French), erythrcmycin (Abbott Laboratories), clindamycin (The Upjohn Co), ciprofloxacin (Miles Pharmaceuticals), ofloxacin (Ortho Pharmaceuticals), temafloxacin (Abbott Laboratories), tetracycline (Antibi6ticos S.A.), gentamicin (Schering-Essex), chloramphenicol (Parke Davis & Co.) and rifampicin (Antibi6ticos S.A.). Agents were supplied as laboratory powders of known potency, and stock solutions were made as recommended by the manufacturers.
Actirity of peptide antibiotics against penkflHn-restetairt pnenmococd
301
Table L Comparative in-vitro activity of 19 antimicrobials against 43 CSF isolates of penicillin-resistant pneumococci
Agent
50%'
MIC (mg/L) 90%'
128
4SO12
4 mg/L). The MIC,,, for erythromycin was 80 mg/L with only 13-9 of the strains were inhibited by concentrations above 4 mg/L. The serotype distribution for the penicillin-resistant strains is summarized in the Table II, with 88-5% of strains belonging to four serotypes (9, 6, 19 and 23). All strains that belonged to serotype 9 showed resistance to penicillin only. All six erythromycinand clindamydn-resistant strains belonged to serotype 6, arid three were also resistant to chloramphenicol and tetracycline (plus penirillin) (Table IT). Twenty-one strains Tabk II. Antibiotic resistance patterns and serotype distribution of 43 penicillin-resistant strains of S. pneumoniae isolated from CSF Resistance to*
P T C E PCT PCTE
No. strains (%)
9 (%)
6 (%)
43 (100) 25 (581) 23 (53-4) 6 (13-9) 21 (48-8) 3(6-9)
15 (34-9) — — — — —
11 (25-6) 10 (40) 9 (39-1) 6 (100) 8 (381) 3 (100)
Serotype distribution 19 (%) 23 (%) 14 (%) 6 (14) 5 (20) 4 (17-4) — 4 (19) —
6 (14) 6 (24) 6 (26-1) — 6 (28-6) —
*P, Penicillin; T, tetracycline; C, chloramphenicol; E, erythromycin-clindamycin.
15 (%)
3(7) 2(8) 3(13)
2 (4-7) 2 (8) 1 4-3)
2(9-5)
1 (48)
—
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
006 025 012 025 1 4 2 05 05 012
SKF104662 Vancomycin Teicoplanin Daptomycin Penicillin Cephalothin Cefuroxime Cefotaxime Ceftriaxone Imipenem Erythromycin Clindamycin Ciprofloxarin Ofloxarin Temafloxacin Tetracycline Chloramphenicol Gentamicin
Range
302
J. L. Rodrfgoez-Tudela et aL
were resistant to penicillin, chloramphenicol and tetracycline: eight of serotype 6, six of serotype 23, four of serotype 19, two of serotype 14 and one of serotype 15 (Table II). Discussion
Acknowledgement This work was supported in part by Comisi6n Interministerial de Ciencia y Tecnologia, grant SAL90-0154. References Cherubin, C. E. (1989). Penetration of antibiotics into the CSF and the treatment of meiningitis: personal commentary andreviewof selected agents-part 1. Antimicrobic Newsletter 6, 77-84. Fenoll, A., Martin Bourgon, C , Mufioz, R., Vicioso, D. & Casal, J. (1991). Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates causing systemic infections in Spain, 1979-1989. Reviews of Infectious Diseases 13, 56-60. Gray, B. M. & Dillon, H. C. (1986). Clinical and epidemiologic studies of pneumococcal infection in children. Pediatric Infectious Diseases 5, 201-7. Jorgensen, J. H., Redding, J. S. & Maher, L. A. (1989). Antibacterial activity of the new glycopeptide antibiotic SKF104662. Antimicrobial Agents and Chemotherapy 33, 560-1. Klugman, K. P. (1990). Pneumococcal resistance to antibiotics. Clinical Microbiology Reviews 3, 171-96. Neu, H. C. (1988). Glycopeptides and lipopeptides. Agents trying to meet the demands of the future. Antimicrobic Newsletter 5, 77-84. (Received 10 July 1991; revised version accepted 29 October 1991)
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
Although some patients with infections caused by penicillin-resistant pneumococci respond to high doses of penicillin, patients with meningitis generally do not, due to the much lower levels of penicillin and other agents achieved in CSF (Cherubin, 1989). All the /Mactams that we tested had decreased activity against penicillin-resistant strains but imipenem, ceftriaxone and cefotaxime still had good in-vitro activity. However, the MIQoS for /Mactams were higher when penicillin-resistant strains were tested than for penicillin-susceptible strains (Klugman, 1990). Chloramphenicol, another antibiotic extensively used in the treatment of meningitis, showed no in-vitro activity against penicillin-resistant S. pneumoniae in Spain. Antibiotics currently available to treat /Mactam resistant pneumococcal meningitis are limited. Vancomycin has excellent activity against /Mactam resistant pneumococci, and has been widely used. Teicoplanin, daptomycin and SKF104662 demonstrated invitro activity comparable to that of vancomycin against the penicillin-resistant pneumococci tested. However, any advantage of the newer antibiotic peptides for the treatment of meningitis caused by /Mactam-resistant pneumococci will depend on their pharmacokinetics and their side effect profile. Serotype 6 has been more frequently associated with pneumococcal meningitis in other countries (Gray & Dillon, 1986). In our study, the higher rates of type 23 and the emergence of serotype 9 may be related to their higher levels of penicillin resistance. In Spain penicillin resistance is found predominantly in serogroup 23 (Fenoll et al., 1991) but there is an increasing number of type 9 isolates with only penicillin resistance (Table II) which suggests a clonal origin of these strains. Nevertheles, serotype 6 is more frequently associated with multiple drug resistance, comprising the only strains found resistant to erythromycin-clindamycin (Table H).
Comparative in-vitro activity of four peptide antibiotics against penicillin-resistant Streptococcus pneumoniae isolated from cerebrospinal fluid (CSF) J. L. Rodrfgnez-Tadda, F. L6pez de Felipe, J. V. Martinez-Saarez* and A. FenoD Servicio de Bacteriologia, Centro National de Microbiologia, 28220 Majadahonda, Madrid, Spain
Introduction The prevalence of penicillin-resistant strains of Streptococcus pneumoniae in Spain is among the highest in the world (Fenoll et al., 1991). S. pneumoniae is an important cause of meningitis. Clinical failures of penicillin in the treatment of meningitis caused by intermediate penicillin-resistant pneumococci have been well documented (Klugman, 1990). Many of these penicillin-resistant strains are resistant to multiple drugs including other 0-lactams, erythromycin, clindamycin, tetracycline, chloramphenicol and aminoglycosides (Klugman, 1990; Fenoll et al., 1991). Daptomycin and SKF 104662 are new lipo- and glycopeptide antibiotics which have activity against Gram-positive pathogens similar to that of teicoplanin and vancomycin (Neu, 1988; Jorgensen, Redding & Maher, 1989). The in-vitro activity of these four peptide antibiotics against 43 penicillin-resistant S. pneumoniae recovered from patients with meningitis was studied, and compared with those of 15 other antimicrobial agents. The serotype distribution of these resistant strains was also examined. Methods Bacterial isolates A total of 43 individual clinical isolates of penicillin-resistant S. pneumoniae recovered from CSF were tested for antimicrobial susceptibility (penicillin MIC > 0-06 mg/L). These were all obtained from different patients in hospitals throughout Spain in 1989 and 1990. For comparative purposes, 17 penicillin-susceptible pneumococci (penicillin 'Corresponding author. 299 0305-7453/92/030299 + 04 SOZOO/0
© 1992 The British Society for Antimicrobial Chemotherapy
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
The in-vitro activity of four peptide antibiotics against 43 penicillin-resistant Streptococcus pneumoniae isolated from cerebrospinal fluid (CSF) was evaluated. The activity of SKF104662 was slightly greater to that of vancomycin, teicoplanin and daptomycin (MICs for 90% of the isolates tested 0-06,0-25,0-12 and 0-25 mg/L, respectively) and superior to the other 15 drugs tested. The serotype of these penicillin-resistant strains was also determined. The strains that belonged to the predominant serotype 9 were resistant only to penicillin. All six erythromycin- and clindamydn-resistant strains belonged to serotype 6 and three of them were also resistant to chloramphenicol and tetracydine (plus penicillin).
300
J. L. Rodrigoez-Tudela et al
MIC < 0-06 mg/L) recovered from blood (ten strains), CSF (six strains) or pulmonary biopsy (one strain), were also tested. S. pneumoniae R6, a penicillin-susceptible, nonencapsulated laboratory strain, Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, and Escherichia coli ATCC 25922 were used as controls in all susceptibility tests. Antimicrobial agents
Susceptibility tests Susceptibility tests were performed by an agar dilution technique with Mueller-Hinton agar supplemented with 5% sheep blood. Inocula of as 10* cfu were prepared by appropriate dilutions in a fresh Todd-Hewitt broth of an overnight culture on blood agar, and applied with a 96-prong inoculating device (Microtiter AM80, Denley-tech, England). Thirty-four strains were tested on each duplicated plate, which were incubated overnight at 37°C. The MIC was read as the lowest concentration of antibiotic that prevented visible growth. Serotype determination All strains were serotyped by the Quellung reaction with specific antisera from the Staten Seruminstitut (Copenhagen). Results The peptide antibiotics showed greater in-vitro activity against penicillin-resistant strains than the other drugs tested (Table I). SKF104662 was slightly more active than the other pep tides tested against penicillin-resistant pneumococci. The MIC*, of penicillin G against penicillin-resistant strains (including intermediate and fully resistant isolates) was 2-0 mg/L (Table I). The pneumococci that were penicillin-resistant were not categorically resistant to third-generation cephalosporins and imipenem, but their MIC^s were 1 and 025 mg/L respectively. In this study the most active /J-lactam drugs in-vitro for penicillin-resistant pneumococci were cefotaxime, ceftriaxone and imipenem. Temafloxacin was the most active among the three quinolones tested. We did not detect a significant level of resistance to rifampicin. The MIC^ was ^ 0-12 mg/L, with only one strain with a MIC value above 16 mg/L.
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
The antimicrobial agents studied included the following: benzylpenicillin (Beecham Laboratories), cephalothin (Eli Lilly & Co.), cefuroxime (Glaxo), cefotaxime (HoechstRoussel Pharmaceuticals Inc.), ceftriaxone (Hoffman-La Roche), imipenem (Merck Sharp & Dohme), vancomycin (Eli Lilly & Co.), teicoplanin (Merrell-Dow Research Institute), daptomycin (Eli Lilly & Co.), SKF104662 (Smith O n e & French), erythrcmycin (Abbott Laboratories), clindamycin (The Upjohn Co), ciprofloxacin (Miles Pharmaceuticals), ofloxacin (Ortho Pharmaceuticals), temafloxacin (Abbott Laboratories), tetracycline (Antibi6ticos S.A.), gentamicin (Schering-Essex), chloramphenicol (Parke Davis & Co.) and rifampicin (Antibi6ticos S.A.). Agents were supplied as laboratory powders of known potency, and stock solutions were made as recommended by the manufacturers.
Actirity of peptide antibiotics against penkflHn-restetairt pnenmococd
301
Table L Comparative in-vitro activity of 19 antimicrobials against 43 CSF isolates of penicillin-resistant pneumococci
Agent
50%'
MIC (mg/L) 90%'
128
4SO12
4 mg/L). The MIC,,, for erythromycin was 80 mg/L with only 13-9 of the strains were inhibited by concentrations above 4 mg/L. The serotype distribution for the penicillin-resistant strains is summarized in the Table II, with 88-5% of strains belonging to four serotypes (9, 6, 19 and 23). All strains that belonged to serotype 9 showed resistance to penicillin only. All six erythromycinand clindamydn-resistant strains belonged to serotype 6, arid three were also resistant to chloramphenicol and tetracycline (plus penirillin) (Table IT). Twenty-one strains Tabk II. Antibiotic resistance patterns and serotype distribution of 43 penicillin-resistant strains of S. pneumoniae isolated from CSF Resistance to*
P T C E PCT PCTE
No. strains (%)
9 (%)
6 (%)
43 (100) 25 (581) 23 (53-4) 6 (13-9) 21 (48-8) 3(6-9)
15 (34-9) — — — — —
11 (25-6) 10 (40) 9 (39-1) 6 (100) 8 (381) 3 (100)
Serotype distribution 19 (%) 23 (%) 14 (%) 6 (14) 5 (20) 4 (17-4) — 4 (19) —
6 (14) 6 (24) 6 (26-1) — 6 (28-6) —
*P, Penicillin; T, tetracycline; C, chloramphenicol; E, erythromycin-clindamycin.
15 (%)
3(7) 2(8) 3(13)
2 (4-7) 2 (8) 1 4-3)
2(9-5)
1 (48)
—
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
006 025 012 025 1 4 2 05 05 012
SKF104662 Vancomycin Teicoplanin Daptomycin Penicillin Cephalothin Cefuroxime Cefotaxime Ceftriaxone Imipenem Erythromycin Clindamycin Ciprofloxarin Ofloxarin Temafloxacin Tetracycline Chloramphenicol Gentamicin
Range
302
J. L. Rodrfgoez-Tudela et aL
were resistant to penicillin, chloramphenicol and tetracycline: eight of serotype 6, six of serotype 23, four of serotype 19, two of serotype 14 and one of serotype 15 (Table II). Discussion
Acknowledgement This work was supported in part by Comisi6n Interministerial de Ciencia y Tecnologia, grant SAL90-0154. References Cherubin, C. E. (1989). Penetration of antibiotics into the CSF and the treatment of meiningitis: personal commentary andreviewof selected agents-part 1. Antimicrobic Newsletter 6, 77-84. Fenoll, A., Martin Bourgon, C , Mufioz, R., Vicioso, D. & Casal, J. (1991). Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates causing systemic infections in Spain, 1979-1989. Reviews of Infectious Diseases 13, 56-60. Gray, B. M. & Dillon, H. C. (1986). Clinical and epidemiologic studies of pneumococcal infection in children. Pediatric Infectious Diseases 5, 201-7. Jorgensen, J. H., Redding, J. S. & Maher, L. A. (1989). Antibacterial activity of the new glycopeptide antibiotic SKF104662. Antimicrobial Agents and Chemotherapy 33, 560-1. Klugman, K. P. (1990). Pneumococcal resistance to antibiotics. Clinical Microbiology Reviews 3, 171-96. Neu, H. C. (1988). Glycopeptides and lipopeptides. Agents trying to meet the demands of the future. Antimicrobic Newsletter 5, 77-84. (Received 10 July 1991; revised version accepted 29 October 1991)
Downloaded from http://jac.oxfordjournals.org/ at Karolinska Institutet on May 25, 2015
Although some patients with infections caused by penicillin-resistant pneumococci respond to high doses of penicillin, patients with meningitis generally do not, due to the much lower levels of penicillin and other agents achieved in CSF (Cherubin, 1989). All the /Mactams that we tested had decreased activity against penicillin-resistant strains but imipenem, ceftriaxone and cefotaxime still had good in-vitro activity. However, the MIQoS for /Mactams were higher when penicillin-resistant strains were tested than for penicillin-susceptible strains (Klugman, 1990). Chloramphenicol, another antibiotic extensively used in the treatment of meningitis, showed no in-vitro activity against penicillin-resistant S. pneumoniae in Spain. Antibiotics currently available to treat /Mactam resistant pneumococcal meningitis are limited. Vancomycin has excellent activity against /Mactam resistant pneumococci, and has been widely used. Teicoplanin, daptomycin and SKF104662 demonstrated invitro activity comparable to that of vancomycin against the penicillin-resistant pneumococci tested. However, any advantage of the newer antibiotic peptides for the treatment of meningitis caused by /Mactam-resistant pneumococci will depend on their pharmacokinetics and their side effect profile. Serotype 6 has been more frequently associated with pneumococcal meningitis in other countries (Gray & Dillon, 1986). In our study, the higher rates of type 23 and the emergence of serotype 9 may be related to their higher levels of penicillin resistance. In Spain penicillin resistance is found predominantly in serogroup 23 (Fenoll et al., 1991) but there is an increasing number of type 9 isolates with only penicillin resistance (Table II) which suggests a clonal origin of these strains. Nevertheles, serotype 6 is more frequently associated with multiple drug resistance, comprising the only strains found resistant to erythromycin-clindamycin (Table H).
