scholarly journals Antipneumococcal Activities of a Ketolide (HMR 3647), a Streptogramin (Quinupristin-Dalfopristin), a Macrolide (Erythromycin), and a Lincosamide (Clindamycin)

1998 ◽  
Vol 42 (4) ◽  
pp. 945-946 ◽  
Author(s):  
A. L. Barry ◽  
P. C. Fuchs ◽  
S. D. Brown
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Macrolide Resistance ◽  
Low Level ◽  
Resistant Strains ◽  
High Level

ABSTRACT Four different compounds belonging to the macrolide-lincosamide-streptogramin B (MLSb) class of antimicrobial agents were tested against 611 Streptococcus pneumoniae strains. The ketolide (HMR 3647, previously RU66647) and the streptogramin (quinupristin-dalfopristin) were both active against pneumococci with high-level MLSb resistance (clindamycin-resistant strains) as well as those with low-level macrolide resistance (clindamycin-susceptible strains).

scholarly journals Genetic Characterization of Fluoroquinolone-Resistant Streptococcus pneumoniae Strains Isolated during Ciprofloxacin Therapy from a Patient with Bronchiectasis

2003 ◽  
Vol 47 (4) ◽  
pp. 1419-1422 ◽  
Author(s):  
Adela G. de la Campa ◽  
María-José Ferrandiz ◽  
Fe Tubau ◽  
Román Pallarés ◽  
Federico Manresa ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Genetic Characterization ◽  
Susceptible Strain ◽  
Low Level ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
High Level ◽  
Level Resistance

ABSTRACT Five Spain9V-3 Streptococcus pneumoniae strains were isolated from a patient with bronchiectasis who had received long-term ciprofloxacin therapy. One ciprofloxacin-susceptible strain was isolated before treatment, and four ciprofloxacin-resistant strains were isolated during treatment. The resistant strains were derived from the susceptible strain either by a parC mutation (low-level resistance) or by parC and gyrA mutations (high-level resistance). This study shows that ciprofloxacin therapy in a patient colonized by susceptible S. pneumoniae may select fluoroquinolone-resistant mutants.

Canadian national survey of prevalence of antimicrobial resistance among clinical isolates of Streptococcus pneumoniae. Canadian Bacterial Surveillance Network.

1996 ◽  
Vol 40 (9) ◽  
pp. 2190-2193 ◽  
Author(s):  
A E Simor ◽  
M Louie ◽  
D E Low
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Beta Lactam ◽  
Surveillance Network ◽  
Antibiotic Resistant ◽  
Intermediate Resistance ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance

The antimicrobial susceptibilities of 1,089 clinical isolates of Streptococcus pneumoniae obtained from 39 laboratories across Canada between October 1994 and August 1995 were determined. A total of 91 isolates (8.4%) demonstrated intermediate resistance (MIC, 0.1 to 1.0 microgram/ml) and 36 (3.3%) had high-level resistance (MIC, > or = 2.0 micrograms/ml) to penicillin. Penicillin-resistant strains were more likely to have been recovered from normally sterile sites (P = 0.005) and to be cross-resistant to several beta-lactam and non-beta-lactam antimicrobial agents (P < 0.05). These results indicate that there has been a recent significant increase in the prevalence of antibiotic-resistant S. pneumoniae in Canada.

scholarly journals Influence of Macrolide Susceptibility on Efficacies of Clarithromycin and Azithromycin against Streptococcus pneumoniae in a Murine Lung Infection Model

2003 ◽  
Vol 47 (2) ◽  
pp. 739-746 ◽  
Author(s):  
Holly L. Hoffman ◽  
Michael E. Klepser ◽  
Erika J. Ernst ◽  
C. Rosemarie Petzold ◽  
Loai Mohammed Sa'adah ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Lung Infection ◽  
Macrolide Resistance ◽  
Saline Control ◽  
Infection Model ◽  
Once Daily ◽  
Low Level ◽  
High Level ◽  
Improvement In Survival ◽  
Level Resistance

ABSTRACT We evaluated the activities of clarithromycin and azithromycin against 19 isolates of Streptococcus pneumoniae using a neutropenic lung infection model. The isolates included five susceptible isolates (clarithromycin and azithromycin MICs, ≤0.12 μg/ml), nine isolates exhibiting low-level, mefA-mediated resistance (clarithromycin and azithromycin MICs, 0.5 to 32 μg/ml), and five isolates expressing high-level, ermB-mediated macrolide resistance (clarithromycin and azithromycin MICs, ≥64 μg/ml). Infected mice were administered either saline (control), clarithromycin (4, 40, or 200 mg/kg of body weight twice daily or 200 mg/kg once daily), or azithromycin (4, 40, or 200 mg/kg once daily or 40 mg/kg twice daily) by oral gavage for 72 h. Mortality was assessed at regular intervals for 10 days, and survival in each group was compared to that of untreated controls. Animals infected with susceptible isolates demonstrated significant improvement in survival compared to the controls following treatment with either agent at doses of ≥40 mg/kg. In contrast, none of the regimens improved the survival of animals infected with isolates exhibiting high-level macrolide resistance. Among mice infected with strains expressing low-level resistance, significant improvement in survival compared to the controls was noted among isolates treated with clarithromycin at 40 (seven of nine isolates) and 200 (nine of nine isolates) mg/kg twice a day and with azithromycin at 40 (one of nine isolates) and 200 (three of nine isolates) mg/kg once a day. Animals infected with isolates of S. pneumoniae exhibiting low-level, mefA-mediated macrolide resistance responded to treatment with clarithromycin at rates similar to those observed among mice infected with fully susceptible isolates.

scholarly journals Antimicrobial resistance of Streptococcus pneumoniae recovered from outpatients in the United States during the winter months of 1994 to 1995: results of a 30-center national surveillance study.

1996 ◽  
Vol 40 (5) ◽  
pp. 1208-1213 ◽  
Author(s):  
G V Doern ◽  
A Brueggemann ◽  
H P Holley ◽  
A M Rauch
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Clinical Laboratory ◽  
Rank Order ◽  
The United States ◽  
Penicillin Resistance ◽  
National Committee ◽  
Medical Centers ◽  
Resistant Strains ◽  
High Level

A total of 1,527 clinically significant outpatient isolates of Streptococcus pneumoniae were prospectively collected in 30 different U.S. medical centers between November 1994 and April 1995. Overall, 23.6% of strains were not susceptible to penicillin, with 14.1% intermediate and 9.5% high-level resistant. The frequencies of recovery of intermediate and high-level resistant strains varied considerably between different medical centers and in different geographic areas. In general, intermediate and high-level penicillin resistance was most common with isolates of S. pneumoniae recovered from pediatric patients. The in vitro activities of 22 other antimicrobial agents were assessed against this collection of isolates. Ampicillin was consistently 1 twofold dilution less active than penicillin. Amoxicillin and amoxicillin-clavulanate were essentially equivalent to penicillin in activity. The rank order of activity for cephalosporins was cefotaxime = ceftriaxone > or = cefpodoxime > or = cefuroxime > cefprozil > or = cefixime > cefaclor = loracarbef > cefadroxil = cephalexin. The National Committee for Clinical Laboratory Standards [Performance Standards for Antimicrobial Susceptibility Testing, Sixth Information Supplement (M100-S6), 1995] has established MIC breakpoints for resistance (i.e., > or = 2 micrograms/ml) with three cephalosporins versus S. pneumoniae, namely, cefotaxime, ceftriaxone, and cefuroxime. The overall percentages of strains resistant to these three antimicrobial agents were 3, 5, and 12, respectively. The overall frequency of resistance was 10% with all three macrolides examined in this study, clarithromycin, erythromycin, and azithromycin. The overall percentages of chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole resistance were 4.3, 7.5, and 18, respectively. The resistance percentages among the cephalosporins, macrolides, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole were consistently higher among penicillin-intermediate strains than among susceptible isolates and even higher still among organisms expressing high-level penicillin resistance. Multiply resistant strains represented 9.1% of the organisms examined in this study. Finally, rifampin resistance was uncommon (i.e., 0.5%), and vancomycin resistance was not detected. The quinopristin-dalfopristin combination was consistently active at concentrations of 0.25 to 4 micrograms/ml, but rates of resistance could not be determined in the absence of established interpretive criteria for MIC results.

scholarly journals High-level fluoroquinolone resistance in Streptococcus pneumoniae requires mutations in parC and gyrA.

1996 ◽  
Vol 40 (12) ◽  
pp. 2760-2764 ◽  
Author(s):  
C Janoir ◽  
V Zeller ◽  
M D Kitzis ◽  
N J Moreau ◽  
L Gutmann
Keyword(s):  
Streptococcus Pneumoniae ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Clinical Samples ◽  
Low Frequencies ◽  
Low Level ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance

The mechanism of high-level fluoroquinolone resistance was studied in strains of Streptococcus pneumoniae, either selected in vitro or isolated from clinical samples. By using DNA from these high-level-resistant strains, low-level-resistant transformants (MIC of pefloxacin, > or = 32 micrograms/ml; MIC of ciprofloxacin, 4 micrograms/ml; MIC of sparfloxacin, 0.50 micrograms/ml) were obtained at high frequencies (ca.10(-2)), while high-level-resistant transformants (MIC of pefloxacin, > or = 64 micrograms/ml; MIC of ciprofloxacin, 16 to 64 micrograms/ml; MIC of sparfloxacin, > or = 8 micrograms/ml) were obtained only at low frequencies (ca.10(-4)). This suggested that mutations in at least two unlinked genes were necessary to obtain high-level resistance. Low-level resistance was associated with ParC mutations (change from Ser to Tyr at position 79 [Ser79Tyr], Ser79Phe, or Asp83Gly). ParC mutations were associated, in high-level-resistant strains and transformants, with alterations in the quinolone resistance-determining region of GyrA (Ser84Tyr, Ser84Phe, and/or Glu88Lys). Low-level resistance was shown to be necessary for expression of the gyrA mutations. No mutation in the region corresponding to the quinolone resistance-determining region of GyrB and no alteration of drug accumulation were found.

scholarly journals Detection of Tn917-Like Sequences within a Tn916-like Conjugative Transposon (Tn3872) in Erythromycin-Resistant Isolates of Streptococcus pneumoniae

1998 ◽  
Vol 42 (9) ◽  
pp. 2312-2318 ◽  
Author(s):  
Linda K. McDougal ◽  
Fred C. Tenover ◽  
Linda N. Lee ◽  
J. Kamile Rasheed ◽  
Jan E. Patterson ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Nucleotide Sequence ◽  
Dna Hybridization ◽  
Antimicrobial Agents ◽  
Kanamycin Resistance ◽  
Sequence Analyses ◽  
Conjugative Transposon ◽  
Resistance Phenotype ◽  
Genetic Elements ◽  
Resistant Strains

ABSTRACT A series of macrolide-lincosamide-streptogramin B (MLS)-resistant pneumococcal isolates of a variety of serotypes was examined and was found to contain Tn917-like elements by DNA-DNA hybridization. Like Tn1545, Tn917 also encodes an ermAM gene but does not mediate resistance to other antimicrobial agents. Furthermore, nucleotide sequence analyses of the DNAs flanking three of the Tn917-like elements revealed that they were inserted into orf9 of a Tn916-like element in a composite transposon-like structure (Tn3872). Other MLS-resistant strains appeared to contain Tn1545-like elements that had suffered a deletion of sequences including the aphA-3 sequences responsible for kanamycin resistance. Thus, the MLS resistance phenotype in pneumococci appears to be mediated by the ermAM present on a much wider variety of genetic elements than was previously appreciated.

scholarly journals Emergence of Penicillin-ResistantStreptococcus Pneumoniaein Southern Ontario, 1993–94

1995 ◽  
Vol 6 (3) ◽  
pp. 157-160 ◽  
Author(s):  
Andrew E Simor ◽  
Anita Rachlis ◽  
Lisa Louie ◽  
Janet Goodfellow ◽  
Marie Louie
Keyword(s):  
Antimicrobial Agents ◽  
Clinical Laboratory ◽  
Tertiary Care ◽  
National Committee ◽  
In Vitro Susceptibility ◽  
Southern Ontario ◽  
Recent Emergence ◽  
Resistant Strains ◽  
High Level

Objective: To determine the prevalence of resistance ofStreptococcus pneumoniaeto penicillin and other antimicrobial agents in metropolitan Toronto.Design: Consecutive pneumococcal isolates from different patients were obtained from two private community-based laboratories and from patients assessed in the emergency department of a tertiary-care teaching hospital in Toronto, Ontario between June and December 1993, and between March and October 1994. In vitro susceptibility testing was done by broth microdilution in accordance with National Committee for Clinical Laboratory Standards guidelines.Results: Twenty (7.3±3.1%) of 274 pneumococcal isolates were resistant to penicillin; six (30%) isolates had high-level resistance (minimal inhibitory concentration [mic] 2.0 μg/mL or greater); and 14 isolates had intermediate resistance (mic0.1 to 1.0 μg/mL). Penicillin-resistant strains were also frequently resistant to tetracycline (55%), cotrimoxazole (50%), erythromycin (40%) and cefuroxime (35%). Resistant strains comprised several serotypes: 19F (six isolates), 9V (three), 23F (three), and one each of 6A, 6B, 14, and 19A; four isolates were nontypeable.Conclusions: There has been a recent emergence of penicillin-resistantS pneumoniaein southern Ontario. National and regional surveillance is warranted to determine the extent of the problem elsewhere in Canada.

scholarly journals Antimicrobial Resistance in Respiratory Tract Streptococcus pneumoniae Isolates: Results of the Canadian Respiratory Organism Susceptibility Study, 1997 to 2002

2003 ◽  
Vol 47 (6) ◽  
pp. 1867-1874 ◽  
Author(s):  
George G. Zhanel ◽  
Lorraine Palatnick ◽  
Kimberly A. Nichol ◽  
Tracy Bellyou ◽  
Don E. Low ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Resistance ◽  
Antibiotic Consumption ◽  
Multidrug Resistant ◽  
Medical Centers ◽  
Intermediate Resistance ◽  
Susceptibility Study ◽  
Resistant Strains ◽  
Canadian Provinces ◽  
High Level

ABSTRACT A total of 6,991 unique patient isolates of Streptococcus pneumoniae were collected from October 1997 to June 2002 from 25 medical centers in 9 of the 10 Canadian provinces. Among these isolates, 20.2% were penicillin nonsusceptible, with 14.6% being penicillin intermediate (MIC, 0.12 to 1 μg/ml) and 5.6% being penicillin resistant (MIC, ≥2 μg/ml). The proportion of high-level penicillin-resistant S. pneumoniae isolates increased from 2.4 to 13.8% over the last 3 years of the study, and the proportion of multidrug-resistant S. pneumoniae isolates increased from 2.7 to 8.8% over the 5-year period. Resistant rates (intermediate and resistant) among non-β-lactam agents were as follows: macrolides, 9.6 to 9.9%; clindamycin, 3.8%; doxycycline, 5.5%; chloramphenicol, 3.9%; and trimethoprim-sulfamethoxazole, 19.0%. Rates of resistance to non-β-lactam agents were higher among penicillin-resistant strains than among penicillin-susceptible strains. No resistance to vancomycin or linezolid was observed; however, 0.1% intermediate resistance to quinupristin-dalfopristin was observed. The rate of macrolide resistance (intermediate and resistant) increased from 7.9 to 11.1% over the 5 years. For the fluoroquinolones, the order of activity based on the MICs at which 50% of isolates are inhibited (MIC50s) and the MIC90s was gemifloxacin > clinafloxacin > trovafloxacin > moxifloxacin > grepafloxacin > gatifloxacin > levofloxacin > ciprofloxacin. The investigational compounds ABT-773 (MIC90, 0.008 μg/ml), ABT-492 (MIC90, 0.015 μg/ml), GAR-936 (tigecycline; MIC90, 0.06 μg/ml), and BMS284756 (garenoxacin; MIC90, 0.06 μg/ml) displayed excellent activities. Despite decreases in the rates of antibiotic consumption in Canada over the 5-year period, the rates of both high-level penicillin-resistant and multidrug-resistant S. pneumoniae isolates are increasing in Canada.

scholarly journals Dynamics of resistance of Streptococcus pneumoniae strains to antibacterial drugs for the period 2015–2019 in Samara: opportunities for overcoming

2020 ◽  
Vol 30 (2) ◽  
pp. 219-226
Author(s):  
S. S. Sobina ◽  
M. O. Zolotov ◽  
A. V. Lyamin ◽  
D. D. Ismatullin ◽  
A. V. Zhestkov
Keyword(s):  
Streptococcus Pneumoniae ◽  
Age Groups ◽  
Statistical Processing ◽  
World Health ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antibacterial Drugs ◽  
Low Level ◽  
Study Results ◽  
Resistant Strains

According to the World Health Organization (WHO), diseases caused by Streptococcus pneumoniae are one of the most dangerous diseases, that can be completely prevented by vaccination. Studies conducted in various regions of the Russian Federation and other countries have revealed certain features in the prevalence of pneumococcus strains, resistant to different antibacterial drugs, which requires local studies among patients of different age groups.The aim of the study was to determine the level of sensitivity of S. pneumoniae, isolated from adult patients, to antibacterial drugs (ABD) and the dynamics of resistance to ABD in Samara for the period of 2015–2019.Methods. A retrospective analysis of data from the microbiological department of clinical diagnostic laboratories of the Clinics of Samara State Medical University, Healthcare Ministry of Russia for 2015–2019 was carried out. The microorganism resistance to several groups of ABD was studied – macrolides (erythromycin, azithromycin, clarithro mycin), cephalosporins (ceftriaxone, cefotaxime), fluoroquinolones (levofloxacin) and penicillin. The sensitivity was determined by the disk diffusion method. Statistical processing was performed using the SPSS Statistic 22.0 program. When comparing groups, the χ2 criterion was used; to compare small groups (n < 5), the exact Fisher test was used.Results. Since 2017, there has been a tendency to increase the frequency of pneumococcus isolation in the carrier group. At the same time, a 3-fold decrease in S. pneumoniae excretion from patients with ENT pathology occurred. The highest sensitivity was detected for cephalosporins – 100% sensitivity of all S. pneumoniae strains, detected from ENT organs and during carriage. There is a low level of pneumococcus resistance to levofloxacin. The general sensitivity to ABD from penicillin group is 96.4–98.8%, while the most common resistant strains were found in patients with respiratory tract damage. The highest resistance of S. pneumoniae was revealed to ABD from the macrolide group with a tendency to increase from 4.6% in 2016 to 14.0% in 2019.Conclusion. According to the study results, a rather low level of resistance of S. pneumoniae to most ABD groups, with the exception of macrolides, was demonstrated in Samara. The greatest number of ABD-insensitive pathogens was isolated in patients with pathology of the bronchopulmonary system. A mandatory microbiological examination of the sputum of such patients is necessary with a determination of the sensitivity of the isolated microorganisms to ABD and subsequent correction of therapy upon the identification of resistant strains. Given the increasing resistance of S. pneumoniae in carriers, it is necessary to vaccinate patients in this group. 

scholarly journals In Vitro Selection of Resistance to Four β-Lactams and Azithromycin in Streptococcus pneumoniae

1998 ◽  
Vol 42 (11) ◽  
pp. 2914-2918 ◽  
Author(s):  
Glenn A. Pankuch ◽  
Shane A. Jueneman ◽  
Todd A. Davies ◽  
Michael R. Jacobs ◽  
Peter C. Appelbaum
Keyword(s):  
Streptococcus Pneumoniae ◽  
In Vitro Selection ◽  
Antimicrobial Agents ◽  
Penicillin G ◽  
Resistance Selection ◽  
Resistant Strains ◽  
Selection Of ◽  
Selection Of Resistance

ABSTRACT Selection of resistance to amoxicillin (with or without clavulanate), cefaclor, cefuroxime, and azithromycin among six penicillin G- and azithromycin-susceptible pneumococcal strains and among four strains with intermediate penicillin sensitivities (azithromycin MICs, 0.125 to 4 μg/ml) was studied by performing 50 sequential subcultures in medium with sub-MICs of these antimicrobial agents. For only one of the six penicillin-susceptible strains did subculturing in medium with amoxicillin (with or without clavulanate) lead to an increased MIC, with the MIC rising from 0.008 to 0.125 μg/ml. Five of the six penicillin-susceptible strains showed increased azithromycin MICs (0.5 to >256.0 μg/ml) after 17 to 45 subcultures. Subculturing in medium with cefaclor did not affect the cefaclor MICs of three strains but and led to increased cefaclor MICs (from 0.5 to 2.0 to 4.0 μg/ml) for three of the six strains, with MICs of other β-lactams rising 1 to 3 twofold dilutions. Subculturing in cefuroxime led to increased cefuroxime MICs (from 0.03 to 0.06 μg/ml to 0.125 to 0.5 μg/ml) for all six strains without significantly altering the MICs of other β-lactams, except for one strain, which developed an increased cefaclor MIC. Subculturing in azithromycin did not affect β-lactam MICs. Subculturing of the four strains with decreased penicillin susceptibility in amoxicillin (with or without clavulanate) or cefuroxime did not select for β-lactam resistance. Subculturing of one strain in cefaclor led to an increase in MIC from 0.5 to 2.0 μg/ml after 19 passages. In contrast to strains that were initially azithromycin susceptible, which required >10 subcultures for resistance selection, three of four strains with azithromycin MICs of 0.125 to 4.0 μg/ml showed increased MICs after 7 to 13 passages, with the MICs increasing to 16 to 32 μg/ml. All azithromycin-resistant strains were clarithromycin resistant. With the exception of strains that contained mefE at the onset, no strains that developed resistance to azithromycin containedermB or mefE, genes that have been found in macrolide-resistant pneumococci obtained from clinic patients.

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