151
|
Appelbaum PC, Spangler SK, Pankuch GA, Philippon A, Jacobs MR, Shiman R, Goldstein EJ, Citron DM. Characterization of a beta-lactamase from Clostridium clostridioforme. J Antimicrob Chemother 1994; 33:33-40. [PMID: 8157571 DOI: 10.1093/jac/33.1.33] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A beta-lactamase-producing strain of Clostridium clostridioforme isolated from human peritoneal fluid was examined by MIC testing and enzyme characterization. MICs of penicillins (64-512 mg/L) were higher than those of cephalosporins (8-128 mg/L); the strain was susceptible to cefoxitin (8 mg/L) and imipenem (1 mg/L). No enhancement of cephalosporin activity occurred when clavulanate was also added, but a limited degree of enhancement of penicillin activity (resulting in beta-lactam MICs higher than available NCCLS breakpoints) occurred when clavulanate, sulbactam or tazobactam was added simultaneously. By contrast, addition of BRL 42715 with amoxycillin, ticarcillin or piperacillin led to a drop in beta-lactam MICs from 512 to < or = 1 mg/L, with a drop from 64 to 1 mg/L when BRL 42715 was added with cefotaxime. All inhibitors were added at fixed concentrations of 2 mg/L. As determined spectrophotometrically, the enzyme hydrolysed penicillin G, cloxacillin and piperacillin (Vmax values (%) 372, 1816, 1001, respectively relative to cephaloridine) more efficiently than cephalosporins (69-191, with cephaloridine as 100%). Km values (microM) varied between 30-308 microM (penicillins) and 2-20 microM (cephalosporins). Relative enzyme efficiency (relative Vmax/Km with cephaloridine as 100) varied from 21-100 (cephalosporins) and 8-77 (penicillins). IC50 values (microM) with nitrocefin, piperacillin and penicillin G substrates (concentrations 20, 100 and 20 microM, respectively) were > 1000, 7, 3.5 (clavulanate); > 1000, 300, 59 (sulbactam), > 1000, 29, 7.7 (tazobactam); 0.0004, 0.001, 0.0018 (BRL 42715). The enzyme was not inhibited by EDTA, cefoxitin, cloxacillin or aztreonam, but was inhibited by pCMB.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
152
|
Citron DM, Appelbaum PC. How far should a clinical laboratory go in identifying anaerobic isolates, and who should pay? Clin Infect Dis 1993; 16 Suppl 4:S435-8. [PMID: 8324163 DOI: 10.1093/clinids/16.supplement_4.s435] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Identification of anaerobic bacteria in specimens from sites of infection due to mixed organisms can be time-consuming and expensive. Laboratories should limit anaerobic workups by testing only those specimens that have been properly collected and transported to the laboratory. Use of selective and differential media for initial processing can provide rapid and relevant information to the clinician. Anaerobes isolated from normally sterile sites and sites of serious infection should always be completely identified. Group- or genus-level identifications may suffice in other instances. The Bacteroides fragilis group of organisms should always be identified because of their virulence and resistance to many antimicrobial agents. Some of the other organisms that warrant identification include Clostridium septicum (associated with gastrointestinal malignancy); Clostridium ramosum, Clostridium innocuum, and Clostridium clostridioforme (which are resistant to antibiotics); Clostridium perfringens (a cause of potentially serious infection); anaerobic cocci (which may be resistant to metronidazole and clindamycin); and fusobacteria (which may be virulent and resistant to clindamycin and penicillin).
Collapse
|
153
|
Barry AL, Fuchs PC, Citron DM, Allen SD, Wexler HM. Methods for testing the susceptibility of anaerobic bacteria to two fluoroquinolone compounds, PD 131628 and clinafloxacin. J Antimicrob Chemother 1993; 31:893-900. [PMID: 8395494 DOI: 10.1093/jac/31.6.893] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The susceptibility of anaerobic bacteria to two new fluoroquinolones, PD 131628 (the bioactive form of PD 131112 or CI-990) and clinafloxacin (CI-960 or PD 127391), was determined with the agar dilution procedures and two media, and one broth microdilution procedure. Sparfloxacin and ciprofloxacin were also tested by the broth microdilution method. One hundred anaerobic isolates and four control strains were tested by the three methods which gave minimum inhibitory concentrations (MICs) that were essentially comparable, but not identical. With the broth microdilution method, the relative potency of the four fluoroquinolones was: clinafloxacin > PD 131628 > sparfloxacin > ciprofloxacin. For the latter three drugs but not clinafloxacin, the MIC values were often near the proposed interpretive breakpoint concentrations, and thus minor methodological differences frequently influenced the interpretive categories. Replicate agar dilution tests in five laboratories established MIC control limits for each of four control strains: those MIC limits could also be used to define the expected performance of the two alternative methods.
Collapse
|
154
|
Lee D, Goldstein EJ, Citron DM, Ross S. Empyema due to Bacteroides gracilis: case report and in vitro susceptibilities to eight antimicrobial agents. Clin Infect Dis 1993; 16 Suppl 4:S263-5. [PMID: 8324129 DOI: 10.1093/clinids/16.supplement_4.s263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We describe a patient with empyema due to Bacteroides gracilis and a viridans streptococcus. Therapy with both cefoxitin and imipenem failed, and the patient remained symptomatic even after thoracotomy was performed. Clinical response occurred after initiation of clindamycin therapy. The susceptibilities of the patient's isolate, other clinical strains, and the reference strain were determined by an agar dilution method. The isolates were generally susceptible to all the agents tested; however, some strains were resistant to clindamycin (MIC, 8 micrograms/mL), penicillin G (MIC90, 16 micrograms/mL), and metronidazole (MIC90, 64 micrograms/mL). The B. gracilis isolate from our patient was susceptible to all agents tested, including cefoxitin and imipenem.
Collapse
|
155
|
Goldstein EJ, Citron DM. Comparative susceptibilities of 173 aerobic and anaerobic bite wound isolates to sparfloxacin, temafloxacin, clarithromycin, and older agents. Antimicrob Agents Chemother 1993; 37:1150-3. [PMID: 8390810 PMCID: PMC187919 DOI: 10.1128/aac.37.5.1150] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The in vitro activities of sparfloxacin, temafloxacin, ciprofloxacin, ofloxacin, clarithromycin, erythromycin, tetracycline, cephalothin, penicillin G, and amoxicillin-clavulanic acid against 173 recent clinical bite wound isolates were determined by agar dilution. Sparfloxacin was active against all strains (MIC for 90% of strains tested, < or = 1 micrograms/ml) except for most fusobacteria and one-third of the Prevotella spp. The other fluoroquinolones had similar activities but higher MICs, especially for streptococci. Clarithromycin was more active against many isolates including Pasteurella multocida than erythromycin, with MICs of < or = 2 micrograms/ml (versus 4 micrograms/ml for erythromycin).
Collapse
|
156
|
Goldstein EJ, Citron DM, Cherubin CE, Hillier SL. Comparative susceptibility of the Bacteroides fragilis group species and other anaerobic bacteria to meropenem, imipenem, piperacillin, cefoxitin, ampicillin/sulbactam, clindamycin and metronidazole. J Antimicrob Chemother 1993; 31:363-72. [PMID: 8486570 DOI: 10.1093/jac/31.3.363] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The in-vitro activity of meropenem, imipenem, piperacillin, cefoxitin, ampicillin/sulbactam, clindamycin and metronidazole was determined against 395 strains of strict and facultative anaerobes, including Gardnerella vaginalis, Lactobacillus spp. and Mobiluncus spp. The activities of meropenem and imipenem were within one dilution of their MIC50 and MIC90 values. One isolate of Bacteroides fragilis, two of Bacteroides distasonis, and two of Bacteroides ovatus showed resistance or diminished susceptibility to meropenem and imipenem. Metronidazole was active against almost all obligate anaerobic isolates. Some non-spore-forming Gram-positive bacilli and lactobacilli were resistant. Ampicillin/sulbactam inhibited almost all isolates at < or = 16/8 mg/L. The activity of clindamycin and cefoxitin was relatively good, but some strains of non-fragilis B. fragilis group species were resistant. Piperacillin was the least active agent tested.
Collapse
|
157
|
Goldstein EJ, Citron DM, Goldman RJ. National hospital survey of anaerobic culture and susceptibility testing methods: results and recommendations for improvement. J Clin Microbiol 1992; 30:1529-34. [PMID: 1624572 PMCID: PMC265323 DOI: 10.1128/jcm.30.6.1529-1534.1992] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The methods for performing anaerobic bacterial isolation and identification continue to change and improve. Anaerobic susceptibility testing has become controversial, and method-dependent variability has been noted. To assess the status of clinical anaerobic bacteriology in the United States, we surveyed, by means of a questionnaire, 120 hospitals, selected at random, with bed capacities of 200 to 1,000, and we received responses from 88 (73%). All hospitals performed cultures for anaerobes. The media and methods used for transport, initial processing, incubation, and identification varies between the different regions in the United States. Thirty percent of laboratories did not perform susceptibility studies, 16% used a reference laboratory, and 54% performed them in house. For half the laboratories, susceptibility testing was performed on isolates depending on the source; in this case, blood cultures were tested by 97% of the laboratories, serious infections were tested by 60%, sterile body sites were tested by 73%, pure cultures were tested by 47%, and tests were done by physician request by 39%. For laboratories doing testing, the broth disk method, no longer sanctioned by the National Committee for Clinical Laboratory Standards, was used most often (56%), followed by microdilution (33%), beta-lactamase testing (25%), macrotube dilution (2%), and agar dilution (2%). The antimicrobial agents tested were as follows: penicillin-ampicillin, 94%; clindamycin, 94%, metronidazole, 90%; chloramphenicol, 80%; cefoxitin, 76%; tetracyclines, 51%; and erythromycin, 45%. All other agents were tested by less than or equal to 25% of laboratories; the methods used could be improved to make the results more timely and consequently more clinically relevant.
Collapse
|
158
|
Goldstein EJ, Citron DM. Comparative activity of ciprofloxacin, ofloxacin, sparfloxacin, temafloxacin, CI-960, CI-990, and WIN 57273 against anaerobic bacteria. Antimicrob Agents Chemother 1992; 36:1158-62. [PMID: 1324640 PMCID: PMC188857 DOI: 10.1128/aac.36.5.1158] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The in vitro activities of seven fluoroquinolones against 290 anaerobes were determined by agar dilution. CI-960 and WIN 57273 inhibited greater than 95% of the strains at less than or equal to 2 micrograms/ml. CI-990 required less than or equal to 16 micrograms/ml. Clustering around 2 to 4 micrograms/ml was noted for Bacteroides fragilis group organisms with CI-990, sparfloxacin, and temafloxacin. Temafloxacin and sparfloxacin inhibited most strains at less than or equal to 2 micrograms/ml. B. fragilis was more susceptible to all quinolones than were the other B. fragilis group strains.
Collapse
|
159
|
Eng RH, Yen K, Smith SM, Citron DM, Goldstein EJ, Greenberg R, Cherubin CE. Escherichia coli resistant to ampicillin/sulbactam. Chemotherapy 1992; 38:399-404. [PMID: 1288964 DOI: 10.1159/000239034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Escherichia coli strains resistant to ampicillin/sulbactam from hospitals in 4 different geographic locations were examined with respect to type and amount of beta-lactamase produced. A total of 5 strains was examined from each region. The isoelectric points of all of the involved beta-lactamases were 5.4, corresponding to TEM-1. Km and Vmax values of the beta-lactamases among the clinical isolates resembled those from the control TEM-1 strain. In an 18-hour broth culture the highly resistant isolates produced 3 times more beta-lactamase as compared to the ampicillin/sulbactam-susceptible isolates. However, the highly resistant strains contained approximately the same amount of plasmid DNA (size of > 6,500 bp) as the susceptible isolates. In transformation experiments, both the resistance and the degree of resistance appeared to have been transferable by plasmids. The mechanism for resistance is likely to be a baseline overproduction of TEM-1 beta-lactamase due to either an alteration in the control of gene expression or simply to an increase in the number of copies of the beta-lactamase gene in the plasmids.
Collapse
|
160
|
Goldstein EJ, Citron DM. Susceptibility of anaerobic bacteria isolated from intra-abdominal infections to ofloxacin and interaction of ofloxacin with metronidazole. Antimicrob Agents Chemother 1991; 35:2447-9. [PMID: 1804024 PMCID: PMC245404 DOI: 10.1128/aac.35.11.2447] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The in vitro activities of ofloxacin alone and in combination with metronidazole against 177 anaerobic bacteria isolated from intra-abdominal infections, as determined by broth microdilution, showed that some Bacteroides fragilis strains were susceptible and that most other B. fragilis group species strains were resistant to ofloxacin. Isolates of other anaerobic species and genera, including those causing female genital tract disease, were generally susceptible to ofloxacin. Ofloxacin in combination with metronidazole usually showed an additive or indifferent interaction but no antagonism.
Collapse
|
161
|
Brazier JS, Citron DM, Goldstein EJ. A selective medium for Fusobacterium spp. THE JOURNAL OF APPLIED BACTERIOLOGY 1991; 71:343-6. [PMID: 1960109 DOI: 10.1111/j.1365-2672.1991.tb03798.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A new selective medium (JVN) for the isolation of Fusobacterium spp. from clinical material is described. The medium incorporates josamycin, vancomycin and norfloxacin (at 3, 4 and 1 microgram/ml, respectively) as the selective agents, plus 5% defibrinated horse blood in Fastidious Anaerobe Agar Base (Lab M). This formula allowed luxuriant growth of all 82 strains (eight recognized species) of fusobacteria tested, while significantly inhibiting 51/51 (100%) strains of facultative anaerobes and 45/51 (88%) strains of other obligate anaerobes. JVN medium allowed the successful isolation of strains of Fusobacterium naviforme, F. nucleatum and F. necrophorum from the gingivae of 9/16 healthy volunteers, and strains of F. varium and F. mortiferum from faecal suspensions seeded with these organisms.
Collapse
|
162
|
Citron DM, Ostovari MI, Karlsson A, Goldstein EJ. Evaluation of the E test for susceptibility testing of anaerobic bacteria. J Clin Microbiol 1991; 29:2197-203. [PMID: 1939571 PMCID: PMC270297 DOI: 10.1128/jcm.29.10.2197-2203.1991] [Citation(s) in RCA: 161] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The susceptibilities of 105 clinical isolates of anaerobic bacteria were determined by a new method, the E test (AB Biodisk, Solna, Sweden), and were compared with the MICs for these organisms obtained by the reference agar dilution method by using supplemented brucella and Wilkins-Chalgren agars. The E test is a plastic strip with a predefined antibiotic gradient immobilized on one side and a MIC interpretive scale printed on the other side. Strips with cefoxitin, cefotaxime, imipenem, penicillin, metronidazole, and clindamycin were used in this study. A suspension of the test strain equal to the visual turbidity of a no. 0.5 McFarland standard was prepared and swabbed onto a 150-mm-diameter plate. The strips were applied in a radial fashion, and the plates were incubated under anaerobic conditions. After growth had occurred, an ellipse of inhibition was seen around each strip. At the point of intersection of the ellipse with the strip, the MIC was read from the interpretive scale. For most antibiotic-organism combinations, the ellipse was clear and the endpoint was sharp. The E-test MICs were interpreted after overnight and 48-h incubation for 58 of the strains. After overnight incubation, 87% of the E-test MICs were within 1 dilution of the agar dilution MICs, and 98% were within 2 dilutions. After 48 h of incubation, agreement was 86 and 97% respectively. E-test MICs obtained for the Bacteroides fragilis group after overnight incubation were more comparable than those obtained after 48 h of incubation to agar dilution MICs determined at 48 h for all drugs except clindamycin. On brucella agar, there was a 2% categorical discrepancy rate between the E-test MICs and agar dilution MICs, which occurred mostly with cefoxitin. The E test is easy to perform and read, is suitable for all anaerobes, can be used to test single patient isolates as needed, and offers the laboratory a reliable method for susceptibility testing of anaerobic bacteria.
Collapse
|
163
|
Goldstein EJ, Citron DM, Cherubin CE. Comparison of the inoculum effect of cefoxitin and other cephalosporins and of beta-lactamase inhibitors and their penicillin-derived components on the Bacteroides fragilis group. Antimicrob Agents Chemother 1991; 35:1868-74. [PMID: 1952860 PMCID: PMC245283 DOI: 10.1128/aac.35.9.1868] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We compared the inoculum effects for 109 recent clinical isolates of the Bacteroides fragilis group of cefoxitin, cefotetan, ceftizoxime, ceftriaxone, and three beta-lactamase inhibitors (clavulanic acid, sulbactam, and tazobactam) and their penicillin-derived components. Bactericidal activity was assayed and morphologic changes were monitored for selected strains exhibiting a large inoculum effect. Ceftizoxime demonstrated the largest inoculum effect, followed by cefotetan and ceftriaxone. The large inoculum effect of ceftizoxime and ceftriaxone was correlated with filamentous transformation at the high inoculum (10(8) CFU/ml) and lack of bactericidal activity suggesting drug destruction or inactivation. Cefotetan was bactericidal for B. fragilis isolates but not for other members of the B. fragilis group. Cefoxitin showed the least inoculum effect and was consistently bactericidal at high (10(8) CFU/ml), standard (10(6) CFU/ml), and low (10(4) CFU/ml) inocula, followed by ampicillin-sulbactam. Piperacillin-tazobactam and ticarcillin-clavulanic acid showed an intermediate inoculum effect. The degree of inoculum effect observed generally correlated with bactericidal activity at all inocula.
Collapse
|
164
|
Talan DA, Citron DM, Overturf GD, Singer B, Froman P, Goldstein EJ. Antibacterial activity of crotalid venoms against oral snake flora and other clinical bacteria. J Infect Dis 1991; 164:195-8. [PMID: 2056205 DOI: 10.1093/infdis/164.1.195] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Despite heavy oral and fang contamination of crotalid species with a wide variety of potentially pathogenic bacteria, crotalid envenomation is associated with a low incidence of bacterial infection. Minimal inhibitory and bactericidal concentrations of venoms from three crotalid species were determined against six aerobic and eight anaerobic reference and oral crotalid microorganisms. All anaerobic isolates were resistant to greater than 20,480 micrograms/ml, whereas variable activity (range, 5-20,480 micrograms/ml) was observed for aerobic strains. Further studies against other aerobic clinical isolates demonstrated that venom had the greatest activity (MIC, less than or equal to 80 micrograms/ml) against staphylococci, Pseudomonas aeruginosa, and Enterobacter, Citrobacter, Proteus, and Morganella species. Inhibitory activity was lost with prolonged incubation for many gram-negative species. Crotalid venoms are broadly active against aerobic gram-negative and -positive bacteria. This activity may play a role in the low incidence of infection after envenomation injuries.
Collapse
|
165
|
Goldstein EJ, Citron DM, Cherubin CE. Comparison of the inoculum effects of members of the family Enterobacteriaceae on cefoxitin and other cephalosporins, beta-lactamase inhibitor combinations, and the penicillin-derived components of these combinations. Antimicrob Agents Chemother 1991; 35:560-6. [PMID: 2039208 PMCID: PMC245050 DOI: 10.1128/aac.35.3.560] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We compared the inoculum effects of 105 recent clinical isolates of the family Enterobacteriaceae on cefoxitin, other cephalosporins, aztreonam, and three beta-lactamase inhibitors (clavulanic acid, sulbactam, and tazobactam) and their penicillin-derived components. Piperacillin and aztreonam showed the largest inoculum effect, and cefoxitin showed the smallest. The other cephalosporins tested (cefotetan, ceftizoxime, and ceftriaxone) showed an intermediate inoculum effect. In general, the inoculum effect was of greater magnitude for the penicillin and beta-lactamase inhibitor combinations than for the cephalosporins tested. Bactericidal activity was assayed and morphologic changes were monitored for selected strains exhibiting a large inoculum effect. MICs correlated with bactericidal activity at an inoculum level of 10(5) CFU/ml, while activity at 10(8) CFU/ml was variable. Cefoxitin demonstrated the least filamentous transformation and the most rapid bactericidal activity. Aztreonam showed the most marked filamentous transformation and was no longer bactericidal at 10(8) CFU/ml. The beta-lactamase inhibitor combinations showed variable bactericidal activity, and regrowth occurred with a number of strains with all three agents tested.
Collapse
|
166
|
Brazier JS, Goldstein EJ, Citron DM, Ostovari MI. Fastidious anaerobe agar compared with Wilkins-Chalgren agar, brain heart infusion agar, and brucella agar for susceptibility testing of Fusobacterium species. Antimicrob Agents Chemother 1990; 34:2280-2. [PMID: 2073122 PMCID: PMC172040 DOI: 10.1128/aac.34.11.2280] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Fastidious anaerobe agar supported the growth of 82 strains of fusobacteria better than brain heart infusion agar, brucella agar, and Wilkins-Chalgren agar. Fastidious anaerobe agar showed less hazing and fewer tailing endpoints with beta-lactam antibiotics. Whole-blood supplementation improved the performance of all media. Wilkins-Chalgren agar without blood failed to support the growth of 17% of the strains. All Fusobacterium ulcerans strains were resistant to clindamycin.
Collapse
|
167
|
Citron DM, Baron EJ, Finegold SM, Goldstein EJ. Short prereduced anaerobically sterilized (PRAS) biochemical scheme for identification of clinical isolates of bile-resistant Bacteroides species. J Clin Microbiol 1990; 28:2220-3. [PMID: 2229345 PMCID: PMC268151 DOI: 10.1128/jcm.28.10.2220-2223.1990] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The rapid identification of isolates of bile-resistant Bacteroides species has clinical and therapeutic relevance because of differences in their patterns of susceptibility and virulence. Five hundred twenty-one strains of bile-resistant Bacteroides species that were previously identified by conventional biochemical methods were reexamined to determine the minimum essential parameters necessary for correct identification. Rapid tests for bile resistance, indole production, and catalase were combined with a novel scheme for biochemical determination of saccharolytic activity on arabinose, trehalose, rhamnose, and/or xylan that included the postincubation addition of bromthymol blue for visual pH determination. Organisms were inoculated into prereduced anaerobically sterilized (PRAS) carbohydrates directly from plates, and identification was complete within 24 h of obtaining a pure culture. Ninety-three percent of bile-resistant Bacteroides species from routine clinical specimens were identified correctly by this scheme; a small number of other indole-positive strains, B. splanchnicus, B. eggerthii, and B. stercoris, were misidentified as B. uniformis.
Collapse
|
168
|
Goldstein EJ, Citron DM, Cole RE, Rangel DM, Seid AS, Ostovari MO. Cefoxitin in the treatment of aerobic and anaerobic infections. Prospective correlation of in vitro susceptibility methods with clinical outcome. HOSPITAL PRACTICE (OFFICE ED.) 1990; 25 Suppl 4:38-45. [PMID: 2120272 DOI: 10.1080/21548331.1990.11704115] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Anaerobic isolates from patients with intra-abdominal infection were tested in vitro by eight methods for susceptibility to cefoxitin. Broth disk elution correlated poorly with clinical outcome. The clinical breakpoint for anaerobic susceptibility to cefoxitin was less than or equal to 32 micrograms/ml.
Collapse
|
169
|
Goldstein EJ, Citron DM, Merkin TE, Pickett MJ. Recovery of an unusual Flavobacterium group IIb-like isolate from a hand infection following pig bite. J Clin Microbiol 1990; 28:1079-81. [PMID: 2351726 PMCID: PMC267872 DOI: 10.1128/jcm.28.5.1079-1081.1990] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
An unusual gram-negative rod (RMA 1571) was isolated from a hand infection following a pig bite. This unclassified isolate was characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, and cellular fatty acid analysis. It was indole positive and produced yellow-pigmented growth, which placed it in the genus Flavobacterium, but its other features, including cellular fatty acid analysis, did not appear to be those of a named species.
Collapse
|
170
|
|
171
|
Goldstein EJ, Citron DM. Susceptibility testing of anaerobes--fact, fancy, and wishful thinking. Clin Ther 1989; 11:710-23. [PMID: 2692817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Some of the problems encountered in anaerobic bacteriology and anaerobic susceptibility testing are reviewed. These include the lack of identification of Bacteroides fragilis group species, standardization of test media, methodology, and clinically relevant minimum inhibitory concentration breakpoints. Methodologic variations may lead to marked differences in the degree of activity reported, especially for newer antimicrobial agents. Studies on the correlation of clinical efficacy and in vitro susceptibility data performed by the various techniques are needed.
Collapse
|
172
|
Goldstein EJ, Citron DM. Annual incidence, epidemiology, and comparative in vitro susceptibilities to cefoxitin, cefotetan, cefmetazole, and ceftizoxime of recent community-acquired isolates of the Bacteroides fragilis group. J Clin Microbiol 1988; 26:2361-6. [PMID: 3235664 PMCID: PMC266893 DOI: 10.1128/jcm.26.11.2361-2366.1988] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The six species of the Bacteroides fragilis group are potent pathogens and commonly have different susceptibility patterns. We determined the relative annual isolation rate of anaerobic bacteria and the susceptibility of B. fragilis group species isolated during 1987 at two community hospitals. The relative frequencies of isolation of 261 strains were as follows: B. fragilis, 61%; B. thetaiotaomicron, 17%; B. distasonis, 7%; B. vulgatus, 6%; B. ovatus, 5%; and B. uniformis, 4%. A total of 234 recent clinical isolates were tested against cefmetazole, cefotetan, cefoxitin, ceftizoxime, clindamycin, imipenem, and piperacillin by a brucella agar dilution method. Imipenem was the most active agent tested with all but three isolates (two B. vulgatus and one B. distasonis) susceptible to less than 2 micrograms/ml. Of the cephalosporins tested, cefoxitin, cefotetan, and cefmetazole were relatively equal against B. fragilis, with 93 to 98% of strains susceptible to 32 micrograms/ml. Ceftizoxime was less active, with an MIC for 90% of strains tested of 128 micrograms/ml and only 75% of isolates susceptible to 32 micrograms/ml. Against B. ovatus, B. vulgatus, B. thetaiotaomicron, and B. uniformis, cefoxitin showed a two- to threefold-superior activity compared with that of cefotetan and cefmetazole. In general, ceftizoxime was much less active, except against B. distasonis, for which 78% of isolates were susceptible to 32 micrograms/ml compared with 68% for cefoxitin, 19% for cefmetazole, and 16% for cefotetan. Clindamycin and piperacillin showed activity similar to that of cefoxitin, except piperacillin was less active versus B. vulgatus and B. distasonis. We therefore suggest that clinical laboratories determine the species of B. fragilis group isolates as well as perform susceptibility studies on the isolates. Clinicians should be aware that while B. fragilis is the most frequent isolate, 38% of isolates are from other, more resistant B. fragilis group species.
Collapse
|
173
|
Goldstein EJ, Citron DM. Comparative activities of cefuroxime, amoxicillin-clavulanic acid, ciprofloxacin, enoxacin, and ofloxacin against aerobic and anaerobic bacteria isolated from bite wounds. Antimicrob Agents Chemother 1988; 32:1143-8. [PMID: 3190202 PMCID: PMC172366 DOI: 10.1128/aac.32.8.1143] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We studied the comparative in vitro activities of 10 oral antimicrobial agents against 147 aerobic and 61 anaerobic bacteria making up species in 13 genera (Staphylococcus aureus, streptococci, Eikenella corrodens, Pasteurella multocida, Haemophilus-Actinobacillus spp., M-5, EF-4, Moraxella spp., Flavobacterium IIb, Bacteroides melaninogenicus, Bacteroides spp., Fusobacterium spp., and Peptostreptococcus spp.) that were isolated from bite wounds. Cefuroxime was generally greater than fourfold more active than cephalexin and cefadroxil against all aerobic isolates, including Pasteurella multocida. The fluoroquinolones were highly active against most aerobic isolates but were less active against anaerobic isolates. Ciprofloxacin was generally more active than either enoxacin or ofloxacin. Discrepancies of greater than 30% in the interpretation of susceptibilities between break points suggested by the National Committee for Clinical Laboratory Standards and those related to oral dose peak levels (one-half to one-quarter of maximum achievable concentrations) were noted in 14% (18 of 130) of the instances.
Collapse
|
174
|
Goldstein EJ, Citron DM, Richwald GA. Lack of in vitro efficacy of oral forms of certain cephalosporins, erythromycin, and oxacillin against Pasteurella multocida. Antimicrob Agents Chemother 1988; 32:213-5. [PMID: 3364944 PMCID: PMC172137 DOI: 10.1128/aac.32.2.213] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The in vitro susceptibility of human isolates of Pasteurella multocida to oral antimicrobial agents from our current study and from a review of the literature suggests that dicloxacillin (oxacillin), erythromycin, clindamycin, cephalexin, cefaclor, and cefadroxil should not be used for empiric therapy of animal bite wounds. Agents that were consistently active against P. multocida were penicillin, ampicillin, amoxicillin-clavulanic acid, tetracycline, minocycline, chloramphenicol, trimethoprim-sulfamethoxazole, and cefuroxime. Possible reasons for the confusion regarding the activity of oral cephalosporins are addressed.
Collapse
|
175
|
Goldstein EJ, Citron DM, Bendon L, Vagvolgyi AE, Trousdale MD, Appleman MD. Potential of topical norfloxacin therapy. Comparative in vitro activity against clinical ocular bacterial isolates. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 1987; 105:991-4. [PMID: 3606460 DOI: 10.1001/archopht.1987.01060070135043] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Norfloxacin, a new fluoroquinolone antibiotic related to nalidixic acid, was evaluated as a topical agent for clinical efficacy in bacterial eye infections. This study reports on the comparative in vitro activity of norfloxacin and ten topical antibiotics (nalidixic acid, polymyxin B, colistin, bacitracin, chloramphenicol, sulfamethoxazole, tetracycline, erythromycin, gentamicin, and tobramycin) against 203 pathogenic eye isolates of 17 genera (37 species). In general, norfloxacin had the greatest potency and broadest spectrum of activity of the agents tested. It was active against Staphylococcus aureus (minimal inhibitory concentration against 90% [MIC90], less than or equal to 1.0 microgram/mL), coagulase-negative staphylococci (MIC90, less than or equal to 1.0 microgram/mL), Pseudomonas aeruginosa (MIC90, less than or equal to 1.0 microgram/mL), and Haemophilus organisms (MIC90, less than or equal to 1.0 microgram/mL).
Collapse
|