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Trinh KV, Ruoff KL, Rees CA, Ponukumati AS, Martin IW, O'Toole GA, Saunders JE. Characterization of Ciprofloxacin Resistance Levels: Implications for Ototopical Therapy. Otol Neurotol 2021; 42:e887-e893. [PMID: 33710149 DOI: 10.1097/mao.0000000000003113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Ciprofloxacin-resistant pathogens are inhibited by high concentrations of ciprofloxacin found in commercially-available ototopical solutions. BACKGROUND Ciprofloxacin-resistant pathogens in otitis media are currently treated with ototopical ciprofloxacin suspensions. This is done irrespective of laboratory-reported ciprofloxacin susceptibility, under the assumption that the high concentration of ciprofloxacin applied topically is sufficient to overcome antimicrobial resistance. METHODS We evaluated 34 ciprofloxacin-resistant isolates consisting of Staphylococcus aureus, Pseudomonas aeruginosa, Corynebacterium spp., and Turicella otitidis. Ciprofloxacin minimum inhibitory concentration (MIC) assays and clinical ototopical solution minimum bactericidal concentration (CMBC) assays were performed. RESULTS Amongst the ciprofloxacin-resistant isolates, ciprofloxacin MICs ranged from 8 to 256 mcg/ml (mean: 87.1 mcg/ml) and CMBCs ranged from 23.4 to 1500 mcg/ml (mean: 237.0 mcg/ml). There were no significant differences with respect to MIC in comparing P. aeruginosa versus Corynebacterium spp. (mean: 53.3 versus 55.2, p = 0.86), S. aureus versus P. aeruginosa (mean: 128.0 versus 53.3, p = 0.34), and S. aureus versus Corynebacterium spp. (mean: 128.0 versus 55.2, p = 0.09). The correlation between ciprofloxacin MIC and CMBC was poor (Pearson's r = -0.08, p = 0.75). CONCLUSIONS Ciprofloxacin-resistant pathogens commonly recovered from otitis media exhibit highly variable ciprofloxacin MIC and CMBC levels. Ciprofloxacin was able to inhibit growth in all isolates tested at MIC levels less than or equal to 256 mcg/ml; however, CMBC's up to 1500 mcg/ml were observed within that same group. The clinical relevance of these in vitro MICs is unclear due in part to higher bactericidal concentrations (CMBC) in several strains. Our results suggest that treatment failures may be due to a combination of factors rather than high-level resistance alone.
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Affiliation(s)
| | - Kathryn L Ruoff
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
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Loman BR, Shrestha CL, Thompson R, Groner JA, Mejias A, Ruoff KL, O'Toole GA, Bailey MT, Kopp BT. Age and environmental exposures influence the fecal bacteriome of young children with cystic fibrosis. Pediatr Pulmonol 2020; 55:1661-1670. [PMID: 32275127 PMCID: PMC7593804 DOI: 10.1002/ppul.24766] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/23/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mechanisms that facilitate early infection and inflammation in cystic fibrosis (CF) are unclear. We previously showed that young CF children with secondhand smoke exposure (SHSe) have increased susceptibility to respiratory infections. We aimed to define the impact of SHSe and other external factors upon the fecal bacteriome in early CF. METHODS Twenty CF infants and children were enrolled, clinical data recorded, and hair nicotine measured as an objective surrogate of SHSe. Fecal samples were collected at clinic visits and bacteriome 16S rRNA gene sequencing performed. RESULTS SHSe was associated with increased alpha diversity and increased relative abundance of Acinetobacter and Akkermansia, along with decreased Bifidobacterium and Lactobacillus. Recent antibiotic exposure predicted bacterial population structure in children less than 2 years of age and was associated with decreased Bacteroides relative abundance. Age was the strongest predictor of overall fecal bacterial composition and positively associated with Blautia and Parabacteroides. Weight for length was negatively associated with Staphylococcus relative abundance. CONCLUSIONS SHSe and other external factors such as antibiotics appear to alter fecal bacterial composition in young CF children, but the strongest predictor of overall composition was age. These findings have implications for understanding the intestinal microbiome in young CF children.
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Affiliation(s)
- Brett R Loman
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis, Columbus, Ohio
| | - Chandra L Shrestha
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis, Columbus, Ohio
| | - Rohan Thompson
- Division of Pulmonary Medicine, Nationwide Children's Hospital, Columbus, Ohio
| | - Judith A Groner
- Division of Primary Care, Nationwide Children's Hospital, Columbus, Ohio
| | - Asuncion Mejias
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Center for Vaccines and Immunity, Columbus, Ohio.,Division of Infectious Diseases, Nationwide Children's Hospital, Columbus, Ohio
| | - Kathryn L Ruoff
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Michael T Bailey
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis, Columbus, Ohio
| | - Benjamin T Kopp
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis, Columbus, Ohio.,Division of Pulmonary Medicine, Nationwide Children's Hospital, Columbus, Ohio
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Price KE, Orazi G, Ruoff KL, Hebert WP, O’Toole GA, Mastoridis P. Mannitol Does Not Enhance Tobramycin Killing of Pseudomonas aeruginosa in a Cystic Fibrosis Model System of Biofilm Formation. PLoS One 2015; 10:e0141192. [PMID: 26506004 PMCID: PMC4624634 DOI: 10.1371/journal.pone.0141192] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/05/2015] [Indexed: 11/18/2022] Open
Abstract
Cystic Fibrosis (CF) is a human genetic disease that results in the accumulation of thick, sticky mucus in the airways, which results in chronic, life-long bacterial biofilm infections that are difficult to clear with antibiotics. Pseudomonas aeruginosa lung infection is correlated with worsening lung disease and P. aeruginosa transitions to an antibiotic tolerant state during chronic infections. Tobramycin is an aminoglycoside currently used to combat lung infections in individuals with CF. While tobramycin is effective at eradicating P. aeruginosa in the airways of young patients, it is unable to completely clear the chronic P. aeruginosa infections in older patients. A recent report showed that co-addition of tobramycin and mannitol enhanced killing of P. aeruginosa grown in vitro as a biofilm on an abiotic surface. Here we employed a model system of bacterial biofilms formed on the surface of CF-derived airway cells to determine if mannitol would enhance the antibacterial activity of tobramycin against P. aeruginosa grown on a more clinically relevant surface. Using this model system, which allows the growth of robust biofilms with high-level antibiotic tolerance analogous to in vivo biofilms, we were unable to find evidence for enhanced antibacterial activity of tobramycin with the addition of mannitol, supporting the observation that this type of co-treatment failed to reduce the P. aeruginosa bacterial load in a clinical setting.
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Affiliation(s)
- Katherine E. Price
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Giulia Orazi
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Kathryn L. Ruoff
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Wesley P. Hebert
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - George A. O’Toole
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail: (GAO); (PM)
| | - Paul Mastoridis
- Novartis Pharmaceutical Corporation, East Hanover, New Jersey, United States of America
- * E-mail: (GAO); (PM)
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Loftus RW, Koff MD, Brown JR, Patel HM, Jensen JT, Reddy S, Ruoff KL, Heard SO, Yeager MP, Dodds TM. The epidemiology of Staphylococcus aureus transmission in the anesthesia work area. Anesth Analg 2015; 120:807-18. [PMID: 24937345 DOI: 10.1213/ane.0b013e3182a8c16a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Little is known regarding the epidemiology of intraoperative Staphylococcus aureus transmission. The primary aim of this study was to examine the mode of transmission, reservoir of origin, transmission locations, and antibiotic susceptibility for frequently encountered S aureus strains (phenotypes) in the anesthesia work area. Our secondary aims were to examine phenotypic associations with 30-day postoperative patient cultures, phenotypic growth rates, and risk factors for phenotypic isolation. METHODS S aureus isolates previously identified as possible intraoperative bacterial transmission events by class of pathogen, temporal association, and analytical profile indexing were subjected to antibiotic disk diffusion sensitivity. The combination of these techniques was then used to confirm S aureus transmission events and to classify them as occurring within or between operative cases (mode). The origin of S aureus transmission events was determined via use of a previously validated experimental model and links to 30-day postoperative patient cultures confirmed via pulsed-field gel electrophoresis. Growth rates were assessed via time-to-positivity analysis, and risk factors for isolation were characterized via logistic regression. RESULTS One hundred seventy S aureus isolates previously implicated as possible intraoperative transmission events were further subdivided by analytical profile indexing phenotype. Two phenotypes, phenotype P (patients) and phenotype H (hands), accounted for 65% of isolates. Phenotype P and phenotype H contributed to at least 1 confirmed transmission event in 39% and 28% of cases, respectively. Patient skin surfaces (odds ratio [OR], 8.40; 95% confidence interval [CI], 2.30-30.73) and environmental (OR, 10.89; 95% CI, 1.29-92.13) samples were more likely than provider hands (referent) to have phenotype P positivity. Phenotype P was more likely than phenotype H to be resistant to methicillin (OR, 4.38; 95% CI, 1.59-12.06; P = 0.004) and to be linked to 30-day postoperative patient cultures (risk ratio, 36.63 [risk difference, 0.174; 95% CI, 0.019-0.328]; P < 0.001). Phenotype P exhibited a faster growth rate for methicillin resistant and for methicillin susceptible than phenotype H (phenotype P: median, 10.32H; interquartile range, 10.08-10.56; phenotype H: median, 10.56H; interquartile range, 10.32-10.8; P = 0.012). Risk factors for isolation of phenotype P included age (OR, 14.11; 95% CI, 3.12-63.5; P = 0.001) and patient exposure to the hospital ward (OR, 41.11; 95% CI, 5.30-318.78; P < 0.001). CONCLUSIONS Two S aureus phenotypes are frequently transmitted in the anesthesia work area. A patient and environmentally derived phenotype is associated with increased risk of antibiotic resistance and links to 30-day postoperative patient cultures as compared with a provider hand-derived phenotype. Future work should be directed toward improved screening and decolonization of patients entering the perioperative arena and improved intraoperative environmental cleaning to attenuate postoperative health care-associated infections.
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Affiliation(s)
- Randy W Loftus
- From the *Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; †The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire; ‡Department of Anesthesiology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa; §Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and ∥Departments of Anesthesiology and Surgery, University of Massachusetts Medical School and UMass Memorial Medical Center, Worcester, Massachusetts
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Loftus RW, Brown JR, Patel HM, Koff MD, Jensen JT, Reddy S, Ruoff KL, Heard SO, Dodds TM, Beach ML, Yeager MP. Transmission Dynamics of Gram-Negative Bacterial Pathogens in the Anesthesia Work Area. Anesth Analg 2015; 120:819-26. [DOI: 10.1213/ane.0000000000000626] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Loftus RW, Koff MD, Brown JR, Patel HM, Jensen JT, Reddy S, Ruoff KL, Heard SO, Yeager MP, Dodds TM. The Dynamics of Enterococcus Transmission from Bacterial Reservoirs Commonly Encountered by Anesthesia Providers. Anesth Analg 2015; 120:827-36. [DOI: 10.1213/ane.0000000000000123] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Brosnan E, Mody K, Zuckerman RA, Ruoff KL, Pipas JM. Multiorgan Streptococcus milleri Abscesses During FOLFIRINOX Chemotherapy in a Patient With Metastatic Pancreatic Cancer. Gastrointest Cancer Res 2014; 7:126-128. [PMID: 25276270 PMCID: PMC4171978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
| | - Kabir Mody
- Gastrointestinal Oncology Program Norris Cotton Cancer Center
| | | | - Kathryn L. Ruoff
- Microbiology Laboratory/Department Pathology Dartmouth-Hitchcock Medical Center Lebanon, NH
| | - J. Marc Pipas
- Gastrointestinal Oncology Program Norris Cotton Cancer Center
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Loftus RW, Brindeiro BS, Kispert DP, Patel HM, Koff MD, Jensen JT, Dodds TM, Yeager MP, Ruoff KL, Gallagher JD, Beach ML, Brown JR. Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a passive catheter care system. Anesth Analg 2012; 115:1315-23. [PMID: 23144441 DOI: 10.1213/ane.0b013e31826d2aa4] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Bacterial contamination of intravascular devices has been associated with increased morbidity and mortality in various hospital settings, including the perioperative environment. Catheter hub disinfection has been shown in an ex vivo model to attenuate intraoperative injection of bacterial organisms originating from the anesthesia provider's hands, providing the impetus for improvement in intraoperative disinfection techniques and compliance. In the current study, we investigated the clinical effectiveness of a new, passive catheter care station in reducing the incidence of bacterial contamination of open lumen patient IV stopcock sets. The secondary aim was to evaluate the impact of this novel intervention on the combined incidence of 30-day postoperative infections and IV catheter-associated phlebitis. METHODS Five hundred ninety-four operating room environments were randomized by a computer-generated list to receive either a novel catheter care bundle (HubScrub and DOCit) or standard caps in conjunction with a sterile, conventional open lumen 3-way stopcock set (24 inch with 3-gang 4-way and T-Connector). Patients underwent general anesthesia according to usual practice and were followed prospectively for 30 postoperative days to identify the development of health care-associated infections (HCAIs) and/or phlebitis. The primary outcome was intraoperative bacterial contamination of the primary stopcock set used by the anesthesia provider(s). The secondary outcome was the combined incidence of 30-day postoperative infections and phlebitis. RESULTS Five hundred seventy-two operating rooms were included in the final analysis. Study groups were comparable with no significant differences in patient, provider, anesthetic, or procedural characteristics. The catheter care station reduced the incidence of primary stopcock lumen contamination compared with standard caps (odds ratio [OR] 0.79, 95% confidence interval [CI] 0.63-0.98, P = 0.034) and was associated with a reduction in the combined incidence of HCAIs and IV catheter-associated phlebitis with and without adjustment for patient and procedural covariates (OR(adjusted) 0.589, 95% CI 0.353-0.984, P = 0.040). The risk-adjusted number needed to treat to eliminate 1 case of lumen contamination was 9 (95% CI 3.4-13.5) patients, whereas the risk-adjusted number needed to treat to eliminate 1 case of HCAI/catheter-associated phlebitis was 17 (95% CI 11.8-17.9) patients. CONCLUSION Intraoperative use of a passive catheter care station significantly reduced open lumen bacterial contamination and the combined incidence of 30-day postoperative infections and phlebitis.
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Affiliation(s)
- Randy W Loftus
- Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr., Lebanon, NH 03756, USA.
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Loftus RW, Patel HM, Huysman BC, Kispert DP, Koff MD, Gallagher JD, Jensen JT, Rowlands J, Reddy S, Dodds TM, Yeager MP, Ruoff KL, Surgenor SD, Brown JR. Prevention of intravenous bacterial injection from health care provider hands: the importance of catheter design and handling. Anesth Analg 2012; 115:1109-19. [PMID: 23051883 DOI: 10.1213/ane.0b013e31826a1016] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Device-related bloodstream infections are associated with a significant increase in patient morbidity and mortality in multiple health care settings. Recently, intraoperative bacterial contamination of conventional open-lumen 3-way stopcock sets has been shown to be associated with increased patient mortality. Intraoperative use of disinfectable, needleless closed catheter devices (DNCCs) may reduce the risk of bacterial injection as compared to conventional open-lumen devices due to an intrinsic barrier to bacterial entry associated with valve design and/or the capacity for surface disinfection. However, the relative benefit of DNCC valve design (intrinsic barrier capacity) as compared to surface disinfection in attenuation of bacterial injection in the clinical environment is untested and entirely unknown. The primary aim of the current study was to investigate the relative efficacy of a novel disinfectable stopcock, the Ultraport zero, with and without disinfection in attenuating intraoperative injection of potential bacterial pathogens as compared to a conventional open-lumen stopcock intravascular device. The secondary aims were to identify risk factors for bacterial injection and to estimate the quantity of bacterial organisms injected during catheter handling. METHODS Four hundred sixty-eight operating room environments were randomized by a computer generated list to 1 of 3 device-injection schemes: (1) injection of the Ultraport zero stopcock with hub disinfection before injection, (2) injection of the Ultraport zero stopcock without prior hub disinfection, and (3) injection of the conventional open-lumen stopcock closed with sterile caps according to usual practice. After induction of general anesthesia, the primary anesthesia provider caring for patients in each operating room environment was asked to perform a series of 5 injections of sterile saline through the assigned device into an ex vivo catheter system. The primary outcome was the incidence of bacterial contamination of the injected fluid column (effluent). Risk factors for effluent contamination were identified in univariate analysis, and a controlled laboratory experiment was used to generate an estimate of the bacterial load injected for contaminated effluent samples. RESULTS The incidence of effluent bacterial contamination was 0% (0/152) for the Ultraport zero stopcock with hub disinfection before injection, 4% (7/162) for the Ultraport zero stopcock without hub disinfection before injection, and 3.2% (5/154) for the conventional open-lumen stopcock. The Ultraport zero stopcock with hub disinfection before injection was associated with a significant reduction in the risk of bacterial injection as compared to the conventional open-lumen stopcock (RR = 8.15 × 10(-8), 95% CI, 3.39 × 10(-8) to 1.96 × 10(-7), P = <0.001), with an absolute risk reduction of 3.2% (95% CI, 0.5% to 7.4%). Provider glove use was a risk factor for effluent contamination (RR = 10.48, 95% CI, 3.16 to 34.80, P < 0.001). The estimated quantity of bacteria injected reached a clinically significant threshold of 50,000 colony-forming units per each injection series. CONCLUSIONS The Ultraport zero stopcock with hub disinfection before injection was associated with a significant reduction in the risk of inadvertent bacterial injection as compared to the conventional open-lumen stopcock. Future studies should examine strategies designed to facilitate health care provider DNCC hub disinfection and proper device handling.
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Affiliation(s)
- Randy W Loftus
- Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr. Lebanon, NH 03756, USA.
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Ruoff KL, Toutain-Kidd CM, Srinivasan M, Lalitha P, Acharya NR, Zegans ME, Schwartzman JD. Corynebacterium macginleyi isolated from a corneal ulcer. Infect Dis Rep 2010; 2:1568. [PMID: 21709740 PMCID: PMC3123035 DOI: 10.4081/idr.2010.e3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/08/2010] [Accepted: 02/08/2010] [Indexed: 11/25/2022] Open
Abstract
We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT). To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.
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Affiliation(s)
- Kathryn L. Ruoff
- Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Christine M. Toutain-Kidd
- Department of Surgery (section of Ophthalmology), Dartmouth Medical School, Hanover, NH, USA, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | | | | | - Nisha R. Acharya
- F.I. Proctor Foundation, University of California, San Francisco, CA, USA
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Michael E. Zegans
- Department of Surgery (section of Ophthalmology), Dartmouth Medical School, Hanover, NH, USA, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
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Zuckerman JB, Zuaro DE, Prato BS, Ruoff KL, Sawicki RW, Quinton HB, Saiman L. Bacterial contamination of cystic fibrosis clinics. J Cyst Fibros 2009; 8:186-92. [DOI: 10.1016/j.jcf.2009.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 12/19/2008] [Accepted: 01/16/2009] [Indexed: 10/21/2022]
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Ng EWM, Costa JR, Samiy N, Ruoff KL, Connolly E, Cousins FV, D'Amico DJ. Contribution of pneumolysin and autolysin to the pathogenesis of experimental pneumococcal endophthalmitis. Retina 2002; 22:622-32. [PMID: 12441729 DOI: 10.1097/00006982-200210000-00014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the contribution of pneumolysin and autolysin, two putative pneumococcal virulence proteins, to the pathogenesis of Streptococcus pneumoniae endophthalmitis. METHODS Endophthalmitis was established in Lewis rats by intravitreal injection of pneumococcal strains at an inoculum of 10 organisms. The virulence of three closely related type 2 S. pneumoniae strains were compared: a pneumolysin-deficient derivative (PLN-A), an autolysin-deficient derivative (AL-6), and their isogenic wild-type parent (D 39). Clinical and histologic inflammation scores were compared 24 hours and 48 hours after inoculation. RESULTS Eyes infected with PLN-A and AL-6 strains showed less anterior segment inflammation clinically at 24 hours than did eyes infected with the wild-type strain. Histologic examination at 24 hours showed significantly less corneal infiltration and vitritis and more relative preservation of retinal tissue in eyes infected with PLN-A and AL-6 strains than in eyes infected with the wild-type strain. At 48 hours, no observable differences between PLN-A and wild-type strains were present clinically or histologically. Histologically, however, the AL-6 strain caused less retinal damage than did the wild-type strain. CONCLUSIONS Intraocular infection with pneumolysin-deficient S. pneumoniae results in less severe tissue damage in the first 24 hours of disease compared with infection with pneumolysin-producing S. pneumoniae. Autolysin-deficient S. pneumoniae shows a similar degree of attenuated virulence. Pneumolysin and autolysin may contribute to the early pathogenesis of pneumococcal endophthalmitis.
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Affiliation(s)
- Eugene W M Ng
- The Wilmer Ophthalmological Institute, and The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Songy WB, Ruoff KL, Facklam RR, Ferraro MJ, Falkow S. Identification of Streptococcus bovis biotype I strains among S. bovis clinical isolates by PCR. J Clin Microbiol 2002; 40:2913-8. [PMID: 12149351 PMCID: PMC120625 DOI: 10.1128/jcm.40.8.2913-2918.2002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2002] [Accepted: 04/24/2002] [Indexed: 11/20/2022] Open
Abstract
Streptococcus bovis causes 24% of all streptococcal infective endocarditis cases. There are many reports linking both S. bovis bacteremia and endocarditis with various forms of gastrointestinal disease (primarily colonic cancers). S. bovis is divided into two biotypes: I and II. The biotype I strain is much more frequently isolated from patients with endocarditis, gastrointestinal disease, or both. We describe here the isolation of biotype I-specific DNA sequences and the development of a PCR test which can identify S. bovis biotype I strains among S. bovis clinical isolates.
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Affiliation(s)
- Wanda B Songy
- Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305, USA
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Affiliation(s)
- Kathryn L Ruoff
- Department of Pathology and Clinical Microbiology Laboratories, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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Abstract
The specter of bioterrorism has captured the attention of government and military officials, scientists, and the general public. Compared to other sectors of the population, clinical microbiologists are more directly impacted by concerns about bioterrorism. This review focuses on the role envisioned for clinical laboratories in response to a bioterrorist event. The microbiology and clinical aspects of the biological agents thought to be the most likely tools of bioterrorists are presented. The historical background of the problem of bioterrorism and an overview of current U.S. preparedness planning, with an emphasis on the roles of health care professionals, are also included.
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Affiliation(s)
- W F Klietmann
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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Abstract
The etiologic agent of seal finger (speck finger) is unknown. Seal finger occurs after a seal bite, and the symptoms include acute pain, swelling, discharge, and, in some cases, there is joint involvement. The discovery of Mycoplasma species in epidemics of seal disease prompted attempts to link seal finger to mycoplasma. Mycoplasma species were isolated in cultures of a specimen from the finger of an aquarium trainer who was bitten by a seal and of a specimen from the front teeth of the biting seal. The two Mycoplasma isolates were identical biochemically; they were serum-dependent and hydrolyzed arginine. The isolates were susceptible to tetracycline but resistant to erythromycin. By growth inhibition and immunofluorescent antibody tests, both strains were identified as Mycoplasma phocacerebrale, a mycoplasma isolated in an epidemic of seal disease occurring in the Baltic Sea. The patient's infection was treated successfully with tetracycline. To our knowledge, this is the first case in which a mycoplasma has been associated with seal finger.
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Affiliation(s)
- A S Baker
- Infectious Diseases Service, Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital, Boston, USA
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Ng EW, Samiy N, Ruoff KL, Cousins FV, Hooper DC, von Gunten S, D'Amico DJ, Baker AS. Treatment of experimental Staphylococcus epidermidis endophthalmitis with oral trovafloxacin. Am J Ophthalmol 1998; 126:278-87. [PMID: 9727522 DOI: 10.1016/s0002-9394(98)00157-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the ocular pharmacokinetics and efficacy of oral trovafloxacin, a novel fluoroquinolone antibiotic, in Staphylococcus epidermidis endophthalmitis. METHODS Albino rabbits (n = 20) were infected with an intravitreal inoculum of S epidermidis (1.0 x 10(8) colony-forming units [CFU/0.1 ml) and 24 hours later received a single oral dose of trovafloxacin (250 mg/kg). Serum and intraocular samples from infected and control (noninfected) eyes were obtained up to 24 hours after antibiotic administration for measurement of trovafloxacin levels. A second group of rabbits (n = 72) was infected intraocularly and randomized 24 hours later to oral trovafloxacin (250 mg/kg twice a day) for 6 days or no treatment (control). Treatment efficacy was assessed by vitreous culture, clinical examination, and histopathology. RESULTS Following a single dose of trovafloxacin, maximal vitreous levels were achieved at 8 hours in infected eyes, with a penetration ratio of 36%. Vitreous levels were greater than 15 times the minimum inhibitory concentration of the strain employed. In animals with established endophthalmitis, treated eyes were sterilized after 5 days (P = .0495) compared with control eyes, which autosterilized at 14 days. Clinical and histologic examination revealed significant amelioration of anterior segment inflammation in treated eyes, although severe destruction of posterior segment structures occurred in both groups after 6 days of therapy. CONCLUSIONS These data support trovafloxacin as a potential oral agent for treatment or prophylaxis of S epidermidis endophthalmitis, although retinal alterations that occur over the period required for vitreous sterilization suggest that it will not replace intravitreal therapy in established endophthalmitis.
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Affiliation(s)
- E W Ng
- Massachusetts Eye and Ear Infirmary, and the Department of Ophthalmology, Harvard Medical School 02114-3096, USA
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19
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Caliendo AM, Hewitt PL, Allega JM, Keen A, Ruoff KL, Ferraro MJ. Performance of a PCR assay for detection of Pneumocystis carinii from respiratory specimens. J Clin Microbiol 1998; 36:979-82. [PMID: 9542920 PMCID: PMC104672 DOI: 10.1128/jcm.36.4.979-982.1998] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This study evaluates the performance of a PCR assay for the detection of Pneumocystis carinii from respiratory specimens that has been designed for use in the clinical microbiology laboratory. The test includes a simple method for nucleic acid extraction and amplification, a colorimetric probe hybridization technique for detection of amplicons, and an internal control to evaluate for the presence of inhibitors of amplification. Two hundred thirty-two clinical specimens (120 induced-sputum [IS] and 112 bronchoalveolar lavage [BAL] specimens) from 168 patients were tested by both immunofluorescent (direct fluorescent-antibody [DFA]) staining and PCR. Of the 112 BAL specimens, 17 were positive for P. carinii by DFA staining and PCR. An additional two specimens were DFA negative and PCR positive. For BAL specimens, the sensitivity and specificity of PCR compared to DFA were 100 and 98%, respectively. Eighteen IS specimens were positive for P. carinii by DFA, and 27 were positive by PCR. One of the 18 DFA-positive IS specimens was negative by PCR; this patient had just completed therapy for P. carinii pneumonia. Of the 10 specimens that were PCR positive and DFA negative, 4 were from patients who had a subsequent BAL specimen that was positive by DFA and PCR. For IS specimens, the sensitivity of DFA and PCR was 82 and 95%, respectively. The specificity of PCR for IS specimens was 94%. Due to the high sensitivity of PCR for the detection of P. carinii from IS specimens, a PCR-based diagnostic test may be a useful screening test and may alleviate the need for bronchoscopy in some patients.
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Affiliation(s)
- A M Caliendo
- Clinical Microbiology Laboratory, Massachusetts General Hospital, Boston 02114, USA.
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20
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Ng EW, Samiy N, Rubins JB, Cousins FV, Ruoff KL, Baker AS, D'Amico DJ. Implication of pneumolysin as a virulence factor in Streptococcus pneumoniae endophthalmitis. Retina 1998; 17:521-9. [PMID: 9428015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To determine if pneumolysin, a multifunctional cytotoxin produced by Streptococcus pneumoniae, may be a virulence determinant in the pathogenesis of pneumococcal endophthalmitis. METHODS Lewis rats (n = 20) were injected intravitreally with purified recombinant pneumolysin at the following doses; 3.9 hemolytic units (HU), 39 HU, 390 HU, 3.9 x 10(3) HU, and 3.9 x 10(4) HU. After 24 hours, eyes were examined clinically and enucleated for histopathologic examination to elucidate the dose-response relationship. To determine the temporal progression of the disease model, a second group of rats (n = 8) were injected intravitreally with 390 HU of pneumolysin. At 6 and 48 hours, eyes were examined clinically and enucleated for histopathology. RESULTS Eyes injected with pneumolysin demonstrated increasing anterior and posterior segment inflammation in response to increasing doses of administered toxin. The onset of inflammation and tissue damage occurred rapidly, and was maximal at 24 to 48 hours. The clinical and histopathologic changes observed mimicked those of S. pneumoniae endophthalmitis. Histopathologic analysis demonstrated rapid onset of iridocyclitis and vitritis with polymorphonuclear leukocyte influx, inner retinal necrosis, and retinal detachment. Retinal pigment epithelial necrosis and choroiditis were noted at the highest doses administered. Inflamed eyes were shown to be sterile. CONCLUSIONS Pneumolysin injected intravitreally induces many of the clinical and histopathologic features of pneumococcal endophthalmitis, and may play an important role in the inflammation and tissue damage that occurs in pneumococcal endophthalmitis.
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Affiliation(s)
- E W Ng
- Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114-3096, USA
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21
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Abstract
In order to investigate the role of Helcococcus kunzii as a colonizer of skin and as a possible participant in diabetic foot ulcers, we used a selective medium to culture both lower- and upper-extremity skin from a study group of podiatry patients (60 diabetics and 60 nondiabetics) and a control group of 50 healthy volunteers. Although differences in colonization were not statistically significant, a trend toward higher colonization rates in the group of podiatry patients was noted. H. kunzii appears to preferentially colonize the skin of the feet, and while its pathogenic role in diabetic foot ulcers is difficult to establish, it may be a previously unrecognized component of the polymicrobial flora characteristically isolated from patients with these infections.
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Affiliation(s)
- J Haas
- Department of Pathology, Massachusetts General Hospital, Boston 02114, USA
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22
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Affiliation(s)
- L B Balsam
- Massachusetts General Hospital, Boston 02114, USA
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23
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Doern GV, Ferraro MJ, Brueggemann AB, Ruoff KL. Emergence of high rates of antimicrobial resistance among viridans group streptococci in the United States. Antimicrob Agents Chemother 1996; 40:891-4. [PMID: 8849246 PMCID: PMC163225 DOI: 10.1128/aac.40.4.891] [Citation(s) in RCA: 208] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Three hundred fifty-two blood culture isolates of viridans group streptococci obtained from 43 U.S. medical centers during 1993 and 1994 were characterized. Included were 48 isolates of "Streptococcus milleri," 219 S. mitis isolates, 29 S. salivarius isolates, and 56 S. sanguis isolates. High-level penicillin resistance (MIC, > or = 4.0 micrograms/ml) was noted among 13.4% of the strains; for 42.9% of the strains, penicillin MICs were 0.25 to 2.0 micrograms/ml (i.e., intermediate resistance). In general, amoxicillin was slightly more active than penicillin. The rank order of activity for five cephalosporins versus viridans group streptococci was cefpodoxime = ceftriaxone > cefprozil = cefuroxime >> cephalexin. The percentages of isolates resistant (MIC, > or = 2 micrograms/ml) to these agents were 15, 17, 18, 20, and 96, respectively. The rates of resistance to erythromycin, tetracycline, and trimethoprim-sulfamethoxazole were 12 to 38%. Resistance to either chloramphenicol or ofloxacin was uncommon (i.e., < 1%). In general, among the four species, S. mitis was the most resistant and "S. milleri" was the most susceptible.
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Affiliation(s)
- G V Doern
- University of Massachusetts Medical Center, Worcester 01655-0219, USA
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24
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Abstract
Clinical isolates of the "Streptococcus milleri" species group were examined by conventional methods and a rapid, commercially available method for the identification of these strains to the species level. The levels of agreement between the identifications obtained with the commercially available system (Fluo-Card Milleri; KEY Scientific, Round Rock, Tex.) and conventional methods were 98% for 50 Streptococcus anginosus strains, 97% for 31 Streptococcus constellatus strains, and 88% for 17 isolates identified as Streptococcus intermedius. Patient records were also studied in order to gain information on the frequency and sites of isolation of each of the three "S. milleri" group species.
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Affiliation(s)
- C E Flynn
- James Holmer Wright Pathology Laboratories, Massachusetts General Hospital, Boston 02114, USA
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25
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Abstract
Traditionally, group C streptococci include four species: Streptococcus equisimilis, S. zooepidemicus, S. equi, and S. dysgalactiae, the first three of which are group C beta-hemolytic streptococci (GCBHS). However, many of the beta-hemolytic streptococci carrying Lancefield group C antigen isolated from clinical specimens are S. milleri. These organisms can be differentiated by colony size. We retrospectively collected data concerning large-colony-forming GCBHS bacteremia that occurred during a period of 8 years at the Massachusetts General Hospital. A total of 222 cases of beta-hemolytic streptococcal bacteremia were identified; data on the Lancefield grouping were available in 192 cases: 45 cases (23.6%) were group A, 96 cases (50%) were group B, 7 cases (3.6%) were group C (large colony forming), and 44 cases (22.9%) were group G. The medical records for cases of large-colony-forming GCBHS bacteremia were reviewed. In one case, the isolate was thought to be a contaminant; the other six cases are reported (five males and one female; mean age, 55 years). All patients had severe underlying conditions, and none had a history of exposure to animals. The clinical syndromes included two cases of cellulitis and one case each of endocarditis, myocardial infarction complicated by infection, pneumonia, and myofasciitis. The diagnoses for two patients with endovascular infections were delayed. Three of the six patients had fatal outcomes, and other two, after prolonged hospitalization, were transferred to a long-term rehabilitation center. We concluded that the severe outcomes reflect delay in diagnosis and treatment as well as the severity of the underlying diseases. The taxonomy of GCBHS is discussed. More reports differentiating large- and small-colony-forming GCBHS are needed.
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Affiliation(s)
- Y Carmeli
- Medical Services, Massachusetts General Hospital, Boston 02114, USA
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26
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Affiliation(s)
- A M Caliendo
- Microbiology Laboratory, Massachusetts General Hospital, Boston 02114, USA
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27
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Abstract
Currently popular agglutination and coagglutination methods for the identification of beta-hemolytic streptococci, although rapid and simple to perform, are costly. Furthermore, they fail to distinguish between clinically relevant species and normal flora of the same serogroup. We investigated the use of a series of four physiologic tests to differentiate beta-hemolytic streptococci and enterococci into five clinically relevant groups. We also investigated the use of a new product, Visi-Spot, and evaluated an alternate method for the detection of beta-D-glucuronidase production. Our results suggest that for most routine processing of beta-hemolytic streptococci, physiologic tests are sufficiently rapid, more accurate, and far less costly to perform than serologic methods. The facility of our scheme is enhanced by the use of the Visi-Spot test and the substitution of a commercially available product for more traditional methods of detecting beta-D-glucuronidase.
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Affiliation(s)
- R Kirby
- James Holmer Wright Pathology Laboratories, Massachusetts General Hospital, Boston 02114, USA
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28
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Bergman S, Selig M, Collins MD, Farrow JA, Baron EJ, Dickersin GR, Ruoff KL. "Streptococcus milleri" strains displaying a gliding type of motility. Int J Syst Bacteriol 1995; 45:235-9. [PMID: 7537057 DOI: 10.1099/00207713-45-2-235] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Isolates belonging to the "Streptococcus milleri" species group that appear to exhibit a gliding type of motility, which is expressed as spreading growth on certain types of agar media, are described. These strains resembled a biotype of "S. milleri" that is usually isolated from genitourinary sources and is notable for its ability to ferment a wide array of carbohydrates. This biotype, which is currently included in the species Streptococcus anginosus, has been implicated in cases of neonatal infection. The "S. milleri" isolates which we studied lacked any observable organelles of motility and gave negative results when they were tested in conventional motility test medium stab cultures. Colonies growing on certain agar media, however, spread over the surfaces of plates and increased in area with increasing time of incubation. Chocolate agar supported maximum spreading, while this characteristic was barely discernible on blood agar. Electron microscopy studies revealed that there was more production of extracellular glycocalyx by motile strains than by a nonmotile isolate having a similar biotype. The results of an analysis of 16S rRNA gene sequences suggested that the motile strains are closely related to S. anginosus and represent a distinct rRNA population within the "S. milleri" species complex.
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Affiliation(s)
- S Bergman
- Pathology Department, Massachusetts General Hospital, Boston 02114, USA
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29
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Collins MD, Facklam RR, Rodrigues UM, Ruoff KL. Phylogenetic analysis of some Aerococcus-like organisms from clinical sources: description of Helcococcus kunzii gen. nov., sp. nov. Int J Syst Bacteriol 1993; 43:425-9. [PMID: 8347503 DOI: 10.1099/00207713-43-3-425] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
16S rRNA gene sequencing studies were performed on some unusual gram-positive catalase-negative cocci of unknown taxonomic position isolated from human clinical sources. Comparative analysis of the sequence data demonstrated that the clinical isolates represent a hitherto-unknown line of descent within the low-G+C-content gram-positive bacteria. On the basis of the phylogenetic findings and the phenotypic distinctiveness of the organisms, it is proposed that they be classified in a new genus, Helcococcus, as Helcococcus kunzii sp. nov. The type strain of H. kunzii is NCFB 2900.
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Affiliation(s)
- M D Collins
- AFRC Institute of Food Research, Reading Laboratory, United Kingdom
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30
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32
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Grayson ML, Eliopoulos GM, Wennersten CB, Ruoff KL, De Girolami PC, Ferraro MJ, Moellering RC. Increasing resistance to beta-lactam antibiotics among clinical isolates of Enterococcus faecium: a 22-year review at one institution. Antimicrob Agents Chemother 1991; 35:2180-4. [PMID: 1803989 PMCID: PMC245356 DOI: 10.1128/aac.35.11.2180] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To identify any change in the antibiotic resistance of Enterococcus faecium, we examined the antibiotic susceptibilities of clinical strains (n = 84) isolated at one institution during the 22 years since 1968. A significant increase in resistance to penicillin was observed during the study period: the MICs of penicillin for 50 and 90% of isolates tested were 16 and 64 micrograms/ml, respectively, from 1969 to 1988 (n = 48; geometric mean MIC, 14 micrograms/ml) , whereas they were 256 and 512 micrograms/ml, respectively, from 1989 to 1990 (n = 36; geometric mean MIC, 123 micrograms/ml) (P less than 0.001). A comparable increase in resistance to ampicillin was also noted (P less than 0.001). No strains produced detectable beta-lactamase. In contrast, susceptibilities to vancomycin, teicoplanin, and ciprofloxacin remained stable. High-level resistance to gentamicin was observed in none of 48 isolates from 1969 to 1988, but was present in 22 of 36 strains (61%) from 1989 to 1990 (P less than 0.001) and was significantly associated with resistance (MIC, greater than or equal to 128 micrograms/ml) to penicillin (P less than 0.001). To assess the potential evolution of antibiotic resistance in this species, clinical isolates (n = 24) were compared with strains isolated in 1968 from a human population in the Solomon Islands that was never exposed to antibiotics. Solomon Island isolates were significantly more susceptible than all clinical strains to penicillin, ampicillin, and vancomycin (P less than 0.001 for each), but they exhibited no differences in susceptibility to teicoplanin or ciprofloxacin. The penicillin-binding affinity of penicillin-binding protein 5 (PBP 5) in penicillin-resistant clinical strains (MIC, 512 micrograms/ml) was notably lower than that in strains with more typical susceptibilities, suggesting an alteration in this PBP as a possible mechanism for increased penicillin resistance. Solomon Island strains most susceptible to penicillin demonstrated a prominent PBP 5* and the absence of PBP 5. These changes in the antibiotic resistance of E. faecium emphasize the importance of identifying this species in patients with serious enterococcal infections and the necessity of assessing its susceptibility to both beta-lactams and aminoglycosides if effective therapy is to be identified.
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Affiliation(s)
- M L Grayson
- Department of Medicine, New England Deaconess Hospital, Boston, Massachusetts 02215
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33
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Grayson ML, Eliopoulos GM, Wennersten CB, Ruoff KL, Klimm K, Sapico FL, Bayer AS, Moellering RC. Comparison of Enterococcus raffinosus with Enterococcus avium on the basis of penicillin susceptibility, penicillin-binding protein analysis, and high-level aminoglycoside resistance. Antimicrob Agents Chemother 1991; 35:1408-12. [PMID: 1929301 PMCID: PMC245181 DOI: 10.1128/aac.35.7.1408] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We reidentified our laboratories' collections of 57 enterococcal isolates previously classified as Enterococcus avium by the API Rapid Strep identification system (Analytab Products, Plainview, N.Y.) with the identification criteria recommended by Facklam and Collins (R. R. Facklam and M. D. Collins, J. Clin. Microbiol. 27: 731-734, 1989). Thirty isolates were identified as true E. avium, 25 isolates were identified as E. raffinosus, and 2 isolates were identified as E. pseudoavium. E. raffinosus could be differentiated from E. avium on the basis of penicillin susceptibility, as follows: MIC for 50% of E. raffinosus isolates tested (MIC50), 32 micrograms/ml; MIC90, 64 micrograms/ml (range, 4 to 64 micrograms/ml); E. avium MIC50, 1 microgram/ml; MIC90, 2 micrograms/ml (range, 0.5 to 2 micrograms/ml). No strains produced detectable beta-lactamase. Penicillin-binding protein (PBP) analysis of all E. raffinosus isolates demonstrated the unique pattern reported previously (M. D. Collins, R. R. Facklam, J. A. E. Farrow, and R. Williamson, FEMS Microbiol. Lett. 57:283-288, 1989); however, a number of newly identified PBPs were noted. Of 25 isolates, 13 had an additional PBP of 77 kDa (designated PBP 6*), while all isolates possessed a 52-kDa PBP (PBP 7) and a 46-kDa PBP (PBP 8). The presence or absence of PBP 6* did not correlate with penicillin susceptibility; however, PBP 7 demonstrated many features suggestive of low penicillin-binding affinity and may represent a possible mechanism for the relative resistance of this species to penicillin, although this hypothesis remains speculative since attempts to develop a penicillin-hypersusceptible E. raffinosus mutant were unsuccessful. E. raffinosus isolates were significantly more likely to exhibit high-level resistance to kanamycin than E. avium strains were (P < 0.001; chi-square); however, no strains demonstrated high-level resistance to gentamicin. No trend toward increasing penicillin resistance was noted among this collection of E. avium and E. raffinosus isolates collected over the past 35 and 14 years, respectively. Relative resistance to penicillin may be a helpful differentiating feature between E. avium and E. raffinosus when assessment of raffinose metabolism is not possible or is indeterminant.
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Affiliation(s)
- M L Grayson
- Department of Medicine, New England Deaconess Hospital, Boston, Massachusetts 02215
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34
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Abstract
Streptococci requiring either pyridoxal or L-cysteine for growth were first observed 30 years ago as organisms forming satellite colonies adjacent to colonies of "helper" bacteria. Although they were previously considered nutritional mutants of viridans streptococcal species, the nutritionally variant streptococci (NVS) are currently thought to belong to distinct species of the genus Streptococcus. NVS strains may display pleomorphic cellular morphologies, depending on their growth conditions, and are distinguished from most other streptococci by enzymatic and serological characteristics and the presence of a cell wall chromophore. NVS are found as normal inhabitants of the oral cavity, and in addition to their participation in endocarditis, they have been isolated from a wide range of clinical specimens. Endocarditis caused by NVS is often difficult to eradicate; combinations of penicillin and an aminoglycoside are recommended for treatment. The unique physiological features of the NVS contribute to the difficulties encountered in their recovery from clinical specimens and may play a role in the problems associated with successful treatment of NVS endocarditis.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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Ormerod LD, Ruoff KL, Meisler DM, Wasson PJ, Kintner JC, Dunn SP, Lass JH, van de Rijn I. Infectious crystalline keratopathy. Role of nutritionally variant streptococci and other bacterial factors. Ophthalmology 1991; 98:159-69. [PMID: 2008273 DOI: 10.1016/s0161-6420(91)32321-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Infectious crystalline keratopathy (ICK) is a chronic corneal infection characterized by interlamellar plaques of gram-positive coccal bacteria in the absence of inflammatory cells. It generally occurs within a corneal graft. Viridans streptococci are usually isolated, but the clinical response to antibiotics is poor and disparate with the in vitro antimicrobial sensitivities. These features suggest the possibility of unusual bacterial factors in pathogenesis. Four cases caused by nutritionally variant viridans streptococci are described. The organisms were fully characterized. They have a rare nutritional requirement for pyridoxal and require defined culture conditions and specific identification. Nutritional variant streptococci (NVS) are principally described as causing endocarditis, another infection involving an avascular collagenous tissue, and exhibiting similar biologic behavior. Electronmicrographic evidence is also adduced that suggests the possible importance of intracorneal glycocalyx deposition. Such factors might explain the anomalous clinical characteristics of this condition.
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Abstract
Conventional tests and commercially available systems were used to determine the species identities of clinical isolates of enterococci. Strict adherence to the conventional test scheme of Facklam and Collins (R. R. Facklam and M. D. Collins, J. Clin. Microbiol. 27:731-734, 1989) resulted in the misidentification of lactose-negative Enterococcus faecalis isolates as Enterococcus solitarius, but this problem was overcome by the application of additional tests. The commercially available systems tested were unable to recognize some of the more recently described enterococcal species. E. faecalis accounted for 87.1% of 302 consecutive isolates. Enterococcus faecium (8.6%), Enterococcus avium (0.7%), Enterococcus durans (0.3%), Enterococcus gallinarum (1.0%), Enterococcus casseliflavus (1.0%), Enterococcus hirae (0.3%), and Enterococcus raffinosus (0.3%) isolates were also identified. None of the isolates produced beta-lactamase, but 15.4% of 235 isolates tested, including 1 strain of E. gallinarum, displayed high-level resistance to gentamicin.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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37
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Abstract
Recent taxonomic changes among the catalase-negative gram-positive cocci have led to the recognition of a separate genus for bacteria previously considered to be members of the genus Streptococcus. Presently, a total of 12 species of the genus Enterococcus have been described. The characteristics, taxonomy and nomenclature of these species, along with the possible clinical implications of revised enterococcal taxonomy, are discussed.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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38
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de la Maza L, Ruoff KL, Ferraro MJ. In vitro activities of daptomycin and other antimicrobial agents against vancomycin-resistant gram-positive bacteria. Antimicrob Agents Chemother 1989; 33:1383-4. [PMID: 2552910 PMCID: PMC172660 DOI: 10.1128/aac.33.8.1383] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A comparative evaluation of daptomycin and eight other antimicrobial agents was performed by the agar dilution technique with 56 strains of vancomycin-resistant gram-positive bacteria, including Leuconostoc, Lactobacillus, and Pediococcus spp. Erythromycin, deptomycin, clindamycin, and gentamicin exhibited the greatest activities, whereas penicillin, ampicillin, and cefotaxime showed moderate activities. The organisms were all highly resistant to vancomycin and cefoxitin.
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Affiliation(s)
- L de la Maza
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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Ruoff KL, Miller SI, Garner CV, Ferraro MJ, Calderwood SB. Bacteremia with Streptococcus bovis and Streptococcus salivarius: clinical correlates of more accurate identification of isolates. J Clin Microbiol 1989; 27:305-8. [PMID: 2915024 PMCID: PMC267297 DOI: 10.1128/jcm.27.2.305-308.1989] [Citation(s) in RCA: 125] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Two biotypes of Streptococcus bovis can be identified by laboratory testing and can be distinguished from the phenotypically similar organism Streptococcus salivarius. We assessed the clinical relevance of careful identification of these organisms in 68 patients with streptococcal bacteremia caused by these similar species. S. bovis was more likely to be clinically significant when isolated from blood (89%) than was S. salivarius (23%). There was a striking association between S. bovis I bacteremia and underlying endocarditis (94%) compared with that of S. bovis II bacteremia (18%). Bacteremia with S. bovis I was also highly correlated with an underlying colonic neoplasm (71% of patients overall, 100% of those with thorough colonic examinations) compared with bacteremia due to S. bovis II or S. salivarius (17% overall, 25% of patients with thorough colonic examinations). We conclude that careful identification of streptococcal bacteremic isolates as S. bovis biotype I provides clinically important information and should be more widely applied.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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40
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Abstract
Recent reports of infections with vancomycin-resistant gram-positive bacteria prompted us to study vancomycin-resistant isolates from human sources to characterize the types of bacteria displaying this phenotype. Thirty-six vancomycin-resistant gram-positive isolates, 14 from clinical specimens and 22 from stool samples, were identified. These isolates were tentatively identified as Lactobacillus spp. (25 strains), Leuconostoc spp. (6 strains), and Pediococcus spp. (3 strains) on the basis of morphology and physiological tests. Two isolates of indeterminate morphology could not be unambiguously assigned to a genus. Four isolates of vancomycin-resistant lactobacilli from normally sterile body sites were considered to be clinically significant. Vancomycin-resistant gram-positive bacteria may represent an emerging class of nosocomial pathogens. Better methods for distinguishing the various genera in the clinical microbiology laboratory are needed.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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Affiliation(s)
- S Hardy
- Children's Service, Massachusetts General Hospital, Boston
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Kachoris M, Ruoff KL, Welch K, Kallas W, Ferraro MJ. Routine culture of stool specimens for Yersinia enterocolitica is not a cost-effective procedure. J Clin Microbiol 1988; 26:582-3. [PMID: 3128584 PMCID: PMC266338 DOI: 10.1128/jcm.26.3.582-583.1988] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Cefsulodin-Irgasin-novobiocin (CIN) agar was used to isolate Yersinia enterocolitica from 3,622 stool specimens received in our laboratory during a 1-year period. Seven specimens (0.2%) yielded Y. enterocolitica strains from a total of five patients. The low frequency of Y. enterocolitica isolation observed, coupled with the isolation of this pathogen from three of the five patients by our standard stool examination protocol, leads us to conclude that routine culture of stool specimens on CIN agar is not a cost-effective procedure.
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Affiliation(s)
- M Kachoris
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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Abstract
"Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological, and physiological characteristics. The species name Streptococcus anginosus has recently been recognized as the approved name for these organisms. Streptococci known as "S. milleri" have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. This review describes the bacteriological aspects of organisms known as "S. milleri," their clinical significance, and the problems encountered with their identification in the clinical laboratory.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston 02114
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Abstract
Seventy-two isolates classified as "Streptococcus milleri" were examined for the presence of various hydrolytic enzymes. While no protein or lipid-degrading activities were demonstrated, some isolates showed DNase and mucopolysaccharide-degrading activities. Beta-hemolytic isolates were more likely to produce these enzymes than were nonhemolytic strains. Isolates of one "S. milleri" biotype (mannitol fermentation positive) were uniformly devoid of all enzyme activities tested.
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Affiliation(s)
- K L Ruoff
- Francis Blake Bacteriology Laboratories, Massachusetts General Hospital, Boston
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Abstract
Rapid miniaturized tests for acetoin production, arginine hydrolysis, and sorbitol fermentation were used for presumptive identification of non-beta-hemolytic "Streptococcus milleri" isolates in 5 h. All 77 "S. milleri" strains tested were Voges-Proskauer positive, arginine hydrolysis positive, and sorbitol fermentation negative. On the basis of these reactions, "S. milleri" was differentiated from isolates of other viridans group streptococcal species and from Streptococcus bovis.
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Boom WH, Piper DJ, Ruoff KL, Ferraro MJ. New cause for false-positive results with the cryptococcal antigen test by latex agglutination. J Clin Microbiol 1985; 22:856-7. [PMID: 4056010 PMCID: PMC268543 DOI: 10.1128/jcm.22.5.856-857.1985] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The highly specific and sensitive latex agglutination test for cryptococcal antigen detection in cerebrospinal fluid is routine in many hospitals. Contamination of cerebrospinal fluid by a minute amount of syneresis fluid (surface condensation) from agar gave a strongly positive reaction which was heat stable, was not eliminated by pronase treatment, and was not detected by the normal rabbit globulin controls. These observations were valid for three commercially available test kits and could represent a preventable cause of some unexplained false-positive tests despite the use of adequate controls.
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Ruoff KL, Kunz LJ, Ferraro MJ. Occurrence of Streptococcus milleri among beta-hemolytic streptococci isolated from clinical specimens. J Clin Microbiol 1985; 22:149-51. [PMID: 4031029 PMCID: PMC268348 DOI: 10.1128/jcm.22.2.149-151.1985] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A total of 256 beta-hemolytic streptococcal isolates were subjected to serological and physiological tests to identify those which could be classified as Streptococcus milleri. S. milleri accounted for 75% of 70 group C isolates, 15% of 69 group G isolates, 75% of 16 nongroupable isolates, and 100% of 20 group F isolates examined. No S. milleri isolates were encountered among the 90 group A streptococci studied. Of the 95 beta-hemolytic S. milleri isolates examined, 81% were recovered from respiratory specimens.
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Abstract
Streptococci identified as Streptococcus bovis, S. bovis variant, and Streptococcus salivarius were examined with respect to physiological and serological characteristics and cellular fatty acid content. Similarities in physiological reactions and problems encountered in serological analysis were noted, suggesting that an expanded battery of physiological tests is needed to definitively identify these streptococci. Cellular fatty acid analysis provided an accurate method for distinguishing S. salivarius from S. bovis and S. bovis variant.
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Ruoff KL, Fishman JA, Calderwood SB, Kunz LJ. Distribution and incidence of viridans streptococcal species in routine clinical specimens. Am J Clin Pathol 1983; 80:854-8. [PMID: 6637890 DOI: 10.1093/ajcp/80.6.854] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Five hundred consecutive isolates of viridans streptococci were identified to the species level in an effort to determine their distribution and incidence in routine clinical specimens. Viridans streptococci accounted for significant percentages of streptococcal isolates from urine, wounds, body fluids, and blood. The most commonly isolated strains belonged to the Streptococcus milleri, Streptococcus mitis, Streptococcus sanguis I, and Streptococcus sanguis II species. Patient charts were reviewed in order to investigate the possible role as a urinary pathogen of strains belonging to a subgroup of S. milleri. Although these strains frequently are isolated from urine, they appear to play no pathogenic role in urinary tract infections.
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