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Jill E. Clarridge - One of the best experts on this subject based on the ideXlab platform.
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1Medical and 2Laboratory Services, Veterans Affairs Medical Center, and Departments of 3Medicine, 4Molecular Virology
2016Co-Authors: Anna Wanahita, Jill E. Clarridge, Daniel M. Musher, Elizabeth A Goldsmith, Jose Rubio, Bhuvaneswari Krishnan, Joann TrialAbstract:Because Streptococcus Milleri Group (SMG) bacteria—Streptococcus constellatus, Strep-tococcus intermedius, and Streptococcus anginosus—exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less com-pletely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties. The Streptococcus Milleri Group (SMG) consists of 3 species of bacteria (Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus) that share
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interaction between human polymorphonuclear leukocytes and Streptococcus Milleri Group bacteria
The Journal of Infectious Diseases, 2002Co-Authors: Anna Wanahita, Jill E. Clarridge, Daniel M. Musher, Elizabeth A Goldsmith, Jose Rubio, Bhuvaneswari Krishnan, Joann TrialAbstract:Because Streptococcus Milleri Group (SMG) bacteria--Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus--exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less completely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties.
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antibiotic susceptibilities of genetically characterized Streptococcus Milleri Group strains
Antimicrobial Agents and Chemotherapy, 2001Co-Authors: Michael Tracy, Jill E. Clarridge, Anna Wanahita, Yevgeny Shuhatovich, Elizabeth A Goldsmith, Daniel M. MusherAbstract:Previous studies of the antibiotic susceptibility of Streptococcus Milleri Group organisms have distinguished among species by using phenotypic techniques. Using 44 isolates that were speciated by 16S rRNA gene sequencing, we studied the MICs and minimum bactericidal concentrations of penicillin, ampicillin, ceftriaxone, and clindamycin for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus. None of the organisms was resistant to beta-lactam antibiotics, although a few isolates were intermediately resistant; one strain of S. anginosus was tolerant to ampicillin, and another was tolerant to ceftriaxone. Six isolates were resistant to clindamycin, with representation from each of the three species. Relatively small differences in antibiotic susceptibilities among species of the S. Milleri Group show that speciation is unlikely to be important in selecting an antibiotic to treat infection caused by one of these isolates.
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Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus (Streptococcus Milleri Group) are of different clinical importance and are not equally associated with abscess
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2001Co-Authors: Jill E. Clarridge, Silvia Attorri, Daniel M. Musher, Jeff Hebert, Sherry A. DunbarAbstract:Difficulties in distinguishing organisms of the "Streptococcus Milleri Group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.
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genotypic and phenotypic characterization of Streptococcus Milleri Group isolates from a veterans administration hospital population
Journal of Clinical Microbiology, 1999Co-Authors: Jill E. Clarridge, Cheryl Osting, Mehri Jalali, Janet Osborne, Michael WaddingtonAbstract:Because identification of the species within the “Streptococcus Milleri” Group is difficult for the clinical laboratory as the species share overlapping phenotypic characteristics, we wished to confirm biochemical identification with identification by 16S rRNA gene sequence analysis. Ninety-four clinical isolates previously identified as the “Streptococcus Milleri” Group were reclassified as S. anginosus, S. constellatus, or S. intermedius with the API 20 Strep system (bioMerieux Vikek, Hazelton, Mo.) and the Fluo-card (Key Scientific, Round Rock, Tex.). In addition, we determined the Lancefield Group, hemolysis, colony size, colony texture, repetitive extragenic palindromic PCR (rep-PCR) pattern, and cellular fatty acid (CFA) profile (MIDI, Newark, Del.). 16S rRNA gene sequence analysis with 40 selected representative strains showed three distinct Groups, with S. constellatus and S. intermedius found to be more closely related to each other than to S. anginosus, and further distinguished a biochemically distinct Group of urogenital isolates within the S. anginosus Group of isolates. Except for strains unreactive with the Fluo-card (8%), all S. anginosus and S. intermedius strains identified by sequencing were similarly identified by biochemical testing. However, 23% of the selected S. constellatus isolates identified by sequencing (9% of all S. constellatus isolates) would have been identified as S. anginosus or S. intermedius by biochemical tests. Although most S. anginosus strains formed one unique cluster by CFA analysis and most S. constellatus strains showed similar rep-PCR patterns, neither method was sufficiently dependable for identification. Whereas Lancefield Group or lactose fermentation did not correspond to sequence or biochemical type, S. constellatus was most likely to be beta-hemolytic and S. intermedius was most likely to have a dry colony type. The most frequent isolate in our population was S. constellatus, followed by S. anginosus. There was an association of S. anginosus with a gastrointestinal or urogenital source, and there was an association of S. constellatus and S. intermedius with both the respiratory tract and upper-body abscesses.
Daniel M. Musher - One of the best experts on this subject based on the ideXlab platform.
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1Medical and 2Laboratory Services, Veterans Affairs Medical Center, and Departments of 3Medicine, 4Molecular Virology
2016Co-Authors: Anna Wanahita, Jill E. Clarridge, Daniel M. Musher, Elizabeth A Goldsmith, Jose Rubio, Bhuvaneswari Krishnan, Joann TrialAbstract:Because Streptococcus Milleri Group (SMG) bacteria—Streptococcus constellatus, Strep-tococcus intermedius, and Streptococcus anginosus—exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less com-pletely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties. The Streptococcus Milleri Group (SMG) consists of 3 species of bacteria (Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus) that share
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interaction between human polymorphonuclear leukocytes and Streptococcus Milleri Group bacteria
The Journal of Infectious Diseases, 2002Co-Authors: Anna Wanahita, Jill E. Clarridge, Daniel M. Musher, Elizabeth A Goldsmith, Jose Rubio, Bhuvaneswari Krishnan, Joann TrialAbstract:Because Streptococcus Milleri Group (SMG) bacteria--Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus--exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less completely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties.
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antibiotic susceptibilities of genetically characterized Streptococcus Milleri Group strains
Antimicrobial Agents and Chemotherapy, 2001Co-Authors: Michael Tracy, Jill E. Clarridge, Anna Wanahita, Yevgeny Shuhatovich, Elizabeth A Goldsmith, Daniel M. MusherAbstract:Previous studies of the antibiotic susceptibility of Streptococcus Milleri Group organisms have distinguished among species by using phenotypic techniques. Using 44 isolates that were speciated by 16S rRNA gene sequencing, we studied the MICs and minimum bactericidal concentrations of penicillin, ampicillin, ceftriaxone, and clindamycin for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus. None of the organisms was resistant to beta-lactam antibiotics, although a few isolates were intermediately resistant; one strain of S. anginosus was tolerant to ampicillin, and another was tolerant to ceftriaxone. Six isolates were resistant to clindamycin, with representation from each of the three species. Relatively small differences in antibiotic susceptibilities among species of the S. Milleri Group show that speciation is unlikely to be important in selecting an antibiotic to treat infection caused by one of these isolates.
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Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus (Streptococcus Milleri Group) are of different clinical importance and are not equally associated with abscess
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2001Co-Authors: Jill E. Clarridge, Silvia Attorri, Daniel M. Musher, Jeff Hebert, Sherry A. DunbarAbstract:Difficulties in distinguishing organisms of the "Streptococcus Milleri Group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.
Michael G. Surette - One of the best experts on this subject based on the ideXlab platform.
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macrolide and clindamycin resistance in Streptococcus Milleri Group isolates from the airways of cystic fibrosis patients
Antimicrobial Agents and Chemotherapy, 2010Co-Authors: Margot E. Grinwis, Christopher D. Sibley, Michael D. Parkins, Christina S. Eshaghurshan, Harvey R. Rabin, Michael G. SuretteAbstract:The members of the Streptococcus Milleri Group (SMG; also known as the Streptococcus anginosus Group), consisting of Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius, are considered commensal organisms notable for their tendency to cause pyogenic infections (33). In a recent population-based epidemiological study it was observed that members of the SMG were responsible for as many invasive streptococcal diseases as all other streptococci combined (25). The members of the SMG are also the most common cause of brain (10, 13) and liver (12, 28) abscesses. Furthermore, members of the SMG are recognized respiratory pathogens. The members of the SMG are commonly associated with pleural empyema (1, 24, 31), especially as a complication of community-acquired pneumonia (1, 35, 45, 48), and there is evidence that the SMG members are a cause of “culture-negative” community-acquired pneumonia (21). Recent studies have shown that the SMG may be an intrinsic component of the cystic fibrosis (CF) airway microbiome, with a high carriage rate observed for the sputum of adult CF patients (20, 36, 37). Moreover, members of the SMG were implicated in a large proportion of pulmonary exacerbations requiring hospitalization of adults with CF (29, 36, 37), and SMG-directed therapy in each case led to clinical resolution, correlating with a decrease in the SMG load. The development and implementation of various suppressive antibiotic strategies have been integral in treating CF (16). A number of strategies are routinely employed as chronic therapies, including suppressive antistaphylococcal beta-lactam therapy (39, 41), aerosolized antibiotics targeting Pseudomonas aeruginosa, including aminoglycosides (32) and colistin (23), and chronic suppressive macrolide therapy (15, 34, 47). In addition, pulmonary exacerbations necessitating acute parenteral antibiotic therapies further increase antibiotic exposure. The impact of these practices has been studied only to a limited extent with organisms of the CF microbiome, aside from classic CF pathogens. Studies have shown that the long-term exposure of CF patients to azithromycin leads to significantly increased macrolide resistance in CF pathogens, such as Staphylococcus aureus and Haemophilus spp. (19, 30, 44), as well as members of the oral flora. Tazumi et al. found that nearly 90% of viridans Group streptococci from patients receiving oral azithromycin therapy were not susceptible to erythromycin and postulated that these organisms may act as reservoirs of antibiotic resistance determinants (42). Antimicrobial susceptibility profiles of clinical isolates of the SMG typically show these organisms to display low levels of resistance to beta-lactams, fluoroquinolones, and clindamycin (2-4, 6, 43, 49). The frequent use of antibiotics for the treatment of classical CF pathogens, such as S. aureus and P. aeruginosa, during pulmonary exacerbation and need for chronic suppressive antimicrobial therapy may result in vastly different resistance profiles of the CF-related SMG. In this study, we determined the antibiotic susceptibility profiles of SMG isolates from the sputum of 46 adult CF patients. Twelve antibiotics were chosen for study; eight of them, including, ceftazidime, cefepime, ceftriaxone, meropenem, azithromycin, ciprofloxacin, trimethoprim-sulfamethoxazole, and rifampin, are commonly employed for CF. Given the fastidious nature of the members of the SMG, many of which fail to grow using standard protocols (5, 7, 8, 37), we also sought to determine if susceptibility testing on brain heart infusion (BHI) agar correlated with the Clinical and Laboratory Standards Institute (CLSI) approved methods. Furthermore, we determined antimicrobial susceptibility profiles of SMG isolates cultured from sites of invasive infections (blood and abscesses) for comparison.
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mckay agar enables routine quantification of the Streptococcus Milleri Group in cystic fibrosis patients
Journal of Medical Microbiology, 2010Co-Authors: Christopher D. Sibley, Margot E. Grinwis, Michael D. Parkins, Harvey R. Rabin, Daniel B Gregson, Tyler R Field, Jens C Norgaard, Michael G. SuretteAbstract:The ‘Streptococcus Milleri’ Group (SMG) has recently been recognized as a contributor to bronchopulmonary disease in cystic fibrosis (CF). Routine detection and quantification is limited by current CF microbiology protocols. McKay agar was developed previously for the semi-selective isolation of this Group. Here, McKay agar was validated against a panel of clinical SMG isolates, which revealed improved SMG recovery compared with Columbia blood agar. The effectiveness of this medium was evaluated by appending it to the standard CF sputum microbiology protocols in a clinical laboratory for a 6-month period. All unique colony types were isolated and identified by 16S rRNA gene sequencing. Whilst a wide variety of organisms were isolated, members of the SMG were the most prevalent bacteria cultured, and McKay agar allowed routine quantification of the SMG from 103 to >108 c.f.u. ml−1 directly from sputum. All members of the SMG were detected [Streptococcus anginosus (40.7 %), Streptococcus intermedius (34.3 %) and Streptococcus constellatus (25 %)] with an overall prevalence rate of 40.6 % in our adult CF population. Without exception, samples where SMG isolates were cultured at 107 c.f.u. ml−1 or greater were associated with pulmonary exacerbations. This study demonstrates that McKay agar can be used routinely to quantify the SMG from complex clinical samples.
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development of real time pcr assays for detection of the Streptococcus Milleri Group from cystic fibrosis clinical specimens by targeting the cpn60 and 16s rrna genes
Journal of Clinical Microbiology, 2010Co-Authors: Adam B Olson, Christopher D. Sibley, Michael G. Surette, L Schmidt, M A Wilcox, Cindi R CorbettAbstract:Cystic fibrosis (CF) is a multiorgan disease, with the majority of mortalities resulting from pulmonary failure due to repeated pulmonary exacerbations. Recently, members of the Streptococcus anginosus Group (S. anginosus, S. constellatus, and S. intermedius), herein referred to as the “Streptococcus Milleri Group” (SMG) have been implicated as important etiological pathogens contributing to pulmonary exacerbations in CF patients. This is partly due to better microbiological detection of the SMG species through the development of a novel specific medium termed “McKay agar.” McKay agar demonstrated that SMG has been an underreported respiratory pathogen contributing to lung exacerbations. Our aim was to develop a real-time PCR assay to expedite the detection of SMG within diagnostic samples. The cpn60 gene was chosen as a target, with all three members amplified using a single hybridization probe set. SMG strain analysis showed that speciation based on melting curve analysis allowed for the majority of the S. constellatus (96%), S. intermedius (94%), and S. anginosus (60%) strains to be correctly identified. To increase specificity for S. anginosus, two 16S rRNA real-time PCR assays were developed targeting the 16S rRNA gene. The 16s_SA assay is specific for S. anginosus (100%), while the 16s_SCI assay is specific for S. constellatus and S. intermedius (100%). These assays can detect 104 genome equivalents in sputum samples, making this a great tool for assessment of the presence of SMG in complex polymicrobial samples. Novel molecular methods were developed providing detection ability for SMG, an emerging opportunistic pathogen.
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The Streptococcus Milleri Population of a Cystic Fibrosis Clinic Reveals Patient Specificity and Intraspecies Diversity
2010Co-Authors: Michael D. Parkins, Harvey R. Rabin, Michael G. SuretteAbstract:The genetic relatedness of Streptococcus Milleri Group isolates from the airways of cystic fibrosis patients was determined by using pulsed-field gel electrophoresis. This study reveals no evidence for patient-to-patient transmission in our patient population; however, within individual patients, complex inter- and intraspecies diversity and dynamics can be observed. In addition to their role in purulent infections (3, 7, 11), members of the Streptococcus Milleri Group (SMG), also known as the Streptococcus anginosus Group, comprised of Streptococ-cus constellatus, Streptococcus intermedius, and Streptococcus anginosus, have emerged as clinically relevant in chronic airway infections in cystic fibrosis (CF) patients and have been impli-cated as etiologic agents of pulmonary exacerbation (6, 10, 13, 14). We have recently described the isolation of a large number of SMG strains from a cohort of CF patients by using the semiselective medium McKay agar (12). This collection of SMG respiratory isolates was not recovered by conventiona
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Characterization of Streptococcus Milleri Group Isolates from Expectorated Sputum of Adult Patients with Cystic Fibrosis
Journal of clinical microbiology, 2009Co-Authors: Margot E. Grinwis, Christopher D. Sibley, Michael D. Parkins, Christina S. Eshaghurshan, Harvey R. Rabin, Michael G. SuretteAbstract:With the recent insights into the Streptococcus Milleri Group (SMG) as pulmonary pathogens in patients with cystic fibrosis (CF), we sought to characterize 128 isolates from the sputum of adults with CF, along with 45 isolates from patients with invasive diseases for comparison. The tests performed included Lancefield Grouping; tests for hemolysis; tests for the production of hyaluronidase, chondroitin sulfatase, DNase, proteases, and hydrogen peroxide; and PCR for the detection of the intermedilysin gene (ily). We also generated biochemical profiles with the Rapid ID Strep 32 API system and tested cell-free supernatants for the presence of the signal molecule autoinducer-2 (AI-2) using a Vibrio harveyi bioassay with a subset of CF strains. The S. intermedius isolates from both strain collections were similar, while the S. constellatus and S. anginosus isolates yielded several biotypes that differed in prevalence between the two strain collections. Beta-hemolytic, Lancefield Group C S. constellatus comprised 74.4% of the S. constellatus isolates from patients with CF but only 13.3% of the corresponding isolates from patients with invasive infections. This was the only S. constellatus biotype associated with pulmonary exacerbations. Hyaluronidase-positive S. anginosus was detected only among the isolates from patients with CF. Strain-to-strain variability in AI-2 expression was evident, with the mean values being the highest for S. anginosus, followed by S. constellatus and then S. intermedius. Cluster analysis and 16S rRNA sequencing revealed that the species of SMG could be accurately determined with a minimum of three phenotypic tests: tests for the Lancefield Group, hyaluronidase production, and chondroitin sulfatase production. Furthermore, isolates from patients with invasive infections clustered with isolates from the sputum of patients with CF, suggesting that the respiratory tract isolates were equally pathogenic.
M Lopezbrea - One of the best experts on this subject based on the ideXlab platform.
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comparison of three methods for identification of Streptococcus Milleri Group isolates to species level
European Journal of Clinical Microbiology & Infectious Diseases, 2000Co-Authors: A Limia, M L Jimenez, Teresa Alarcon, M LopezbreaAbstract:A collection of 180 clinical isolates of Streptococcus Milleri Group were identified to species level using two phenotypic methods (a commercial system and the reference method based on differential phenotypic reactions) and a genotypic method (hybridisation of the 16S rRNA gene with species-specific probes) in order to evaluate the performance of the respective methods. A high level of agreement (80%) was observed between the results of the reference method and the genotypic method. The highest level of agreement was found for the species Streptococcus anginosus (83%), a high level of agreement (76%) also being achieved for Streptococcus constellatus and Streptococcus intermedius. The sensitivity of the commercial system compared to the genotypic method was 76% overall, but it was low (57.5%) for Streptococcus intermedius. Twenty-five strains belonged to the recently described CI strains.
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five year analysis of antimicrobial susceptibility of the Streptococcus Milleri Group
European Journal of Clinical Microbiology & Infectious Diseases, 1999Co-Authors: A Limia, M L Jimenez, Teresa Alarcon, M LopezbreaAbstract:Susceptibility to 17 antibiotics was studied in 180 strains of the Streptococcus Milleri Group (88 Streptococcus anginosus, 63 Streptococcus constellatus, and 29 Streptococcus intermedius) isolated over a 5-year period. Minimum inhibitory concentrations of penicillin were in the intermediate range for 5.6% of the strains. Resistance to erythromycin and clindamycin was found in 17.1% and 16.6% of the isolates, respectively. A steady increase in the susceptibility to ciprofloxacin was observed over the study period. Imipenem was the most active beta-lactam agent tested. Glycopeptide antibiotics showed excellent activity. Only slight differences between the three species were found in terms of antibiotic susceptibility. Intermediate resistance to penicillin is appearing among the Streptococcus Milleri Group in our area; consequently, care must be taken when choosing a macrolide for the management of infections caused by these microorganisms.
Jan Jacobs - One of the best experts on this subject based on the ideXlab platform.
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in vitro antimicrobial susceptibility of the Streptococcus Milleri Group Streptococcus anginosus Streptococcus constellatus and Streptococcus intermedius
Journal of Antimicrobial Chemotherapy, 1996Co-Authors: Jan Jacobs, E E StobberinghAbstract:A collection of 423 clinical "Streptococcus Milleri' strains was speciated and tested for susceptibilities to twelve antibiotics. Only 1.4% of the strains were of intermediate susceptibility to penicillin. None of the strains exhibited high-level resistance to gentamicin. Strains resistant to erythromycin, roxithromycin and clindamycin were found with a frequency of 2.6%, 2.4% and 2.4% respectively. Doxycycline resistance was found in 5.7% of the strains and occurred most frequently in Streptococcus anginosus. All the strains were susceptible to cefotaxime, vancomycin and teicoplanin. The results of this study do not indicate changing antibiotic resistance in strains of the "S. Milleri' Group, but local differences in antibiotic susceptibilities may occur.
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bacteremia involving the Streptococcus Milleri Group analysis of 19 cases
Clinical Infectious Diseases, 1994Co-Authors: Jan Jacobs, Henk G Pietersen, E E Stobberingh, Peter B SoetersAbstract:During a 3-year study period, 19 patients at the University Hospital of Maastricht developed bloodstream infections with species of the "Streptococcus Milleri" Group, for an incidence of 0.33 per 1,000 admissions. The patients' median age was 48 years; the male-to-female ratio was 2.8. Eleven patients (57.9%) had underlying diseases, among which malignancy was predominant. Local trauma to the mucosal barrier was an important risk factor. An associated site of infection was found most frequently in the abdominal and thoracic cavities (nine and five cases, respectively). Bacteremia was polymicrobial in four of 19 episodes. The 20 infecting S. Milleri strains were identified to the species level; Streptococcus anginosus was the most prevalent (16 strains). Eight strains carried Lancefield Group C. The isolates were sensitive to most antibiotics. Abscess formation was documented in nine cases (47.3%); repeated drainage procedures were required in half of these episodes. Mortality was high (five of 19 patients, or 26.3%).