Biomedical subjects

B Leonhard

Publications and source records attributed to B Leonhard.

34 records · Page 2Linked to original sources

PubMedDate not supplied

Stenotrophomonas (Xanthomonas) maltophilia: in vitro susceptibility to selected antimicrobial drugs, single and combined, with and without defibrinated human blood.

Sixteen selected isolates of Stenotrophomonas maltophilia varied in susceptibility to the combined phagocytic/serum bactericidal activity of fresh defibrinated human blood (65 vol%). Four representative isolates (X1, X11, X25, and X50), which differed in susceptibility to cefepime, ceftazidime, rifampin, and timentin, were subjected to checkerboard microtiter broth dilution tests involving combinations of cefepime plus timentin, ceftazidime plus ofloxacin, cotrimoxazole plus timentin, rifampin plus polymyxin B, and rifampin plus polymyxin B nonapeptide; all combinations yielded additive or synergistic effects against all four strains. Unexpectedly, the combination of cefepime plus timentin was bactericidally active against the two cefepime-resistant isolates. This finding was substantiated by blood/broth plus combined antimicrobial drug assays. Cefepime plus timentin effectively killed all four test strains. Ofloxacin combined with ceftazidime was bactericidally active against the test strains, including two isolates (X11, X50) with intermediate ofloxacin sensitivity. Cotrimoxazole plus timentin in blood, but not in broth, was bactericidal for the timentin-resistant isolate X25. As expected, various triple combinations of chemotherapeutic agents in blood and broth revealed polymyxin B plus rifampin, regardless of the third combination partner, to exert bactericidal activity against all test strains. Similarly, rifampin combined with ofloxacin and ceftazidime was bactericidally active in blood and broth. The observation that timentin combined with cefepime was effective against cefepime-resistant strains of S. maltophilia might prove of clinical relevance with regard to chemotherapy of nosocomial infections due to multiple-antibiotic resistant strains of this opportunistic pathogen.

Anti-Bacterial Agents↗

PubMedDate not supplied

Simple combined agar-strip test for detection of enterococcal susceptibility to ampicillin, moderate- or high-level gentamicin resistance and potential additive activity of ampicillin plus gentamicin.

A simple combined agar-strip test (CAST), involving filter paper strips charged with 20 micrograms of ampicillin or 40 micrograms of gentamicin, accurately detected high-level gentamicin resistance among 43 of 146 isolates of Enterococcus faecalis and additive activity of ampicillin plus gentamicin against 101 of 103 (98%) isolates of E. faecalis with moderate-level gentamicin resistance (MLGR). All 15 MLGR Enterococcus faecium isolates were moderately to highly resistant to ampicillin; 5 isolates with moderate resistance to ampicillin (minimal inhibitory concentrations = 16 micrograms/ml) were additively inhibited by ampicillin plus gentamicin, whereas the highly ampicillin-resistant E. faecium isolates yielded an indifferent effect with the CAST procedure.

Ampicillin↗

PubMedDate not supplied

Enterococcus faecalis: in vitro activity of antimicrobial drugs, singly and combined, with and without defibrinated human blood, against high-level-gentamicin-resistant isolates.

Teicoplanin (4 micrograms/ml) combined with 4 micrograms/ml of ampicillin, mezlocillin, and piperacillin, respectively, proved more efficacious than vancomycin (4 micrograms/ml) combined with the three beta-lactam antibiotics against three representative clinical isolates of Enterococcus faecalis that showed high-level-gentamicin resistance (HLGR). In the presence of 65% (v/v) of fresh defibrinated human blood, teicoplanin (4 micrograms/ml) alone afforded significant bactericidal activity, but failed to completely sterilize assay tube contents, whereas teicoplanin combined with any of the three beta-lactam antibiotics consistently and completely killed HLGR E. faecalis inocula.

Ampicillin↗

PubMedDate not supplied

Enterococcus faecium: in vitro activity of antimicrobial drugs, singly and combined, with and without defibrinated human blood, against multiple-antibiotic-resistant strains.

The minimal inhibitory (MICs) and bactericidal concentrations of 14 antimicrobial drugs were determined against 17 clinical isolates of Enterococcus faecium, including 4 glycopeptide-resistant strains. Both teicoplanin and vancomycin lacked bactericidal activity against all 13 susceptible isolates. Time-kill experiments served to test various antibiotic combinations chiefly against glycopeptide-resistant strains in Mueller-Hinton broth (MHB) and in MHB supplemented with 65% (v/v) fresh defibrinated human blood. Co-trimoxazole, fusidic acid, and novobiocin yielded bacteriostatic effects. Rifampin was bactericidally active against rifampin-susceptible strains (MICs = 0.125 micrograms/ml), but less so against low-level-rifampin-resistant (MICs = 2-8 micrograms/ml) strains in MHB. However, in the presence of human blood, rifampin (2 micrograms/ml) combined with co-trimoxazole (0.25/4.75 micrograms/ml) killed rifampin-susceptible and low-level-rifampin-resistant, but not moderate-level-rifampin-resistant (MICs = 16-32 micrograms/ml) strains of E. faecium. Of two topical drugs examined, mupirocin merely inhibited strains of E. faecium; conversely, taurolidine at 2,000 micrograms/ml was efficacious against all strains examined, although the kinetics of bactericidal activity were retarded somewhat in the presence of 65 vol% human blood.

Anti-Bacterial Agents↗

PubMedDate not supplied

Taurolidine: in vitro activity against multiple-antibiotic-resistant, nosocomially significant clinical isolates of Staphylococcus aureus, Enterococcus faecium, and diverse Enterobacteriaceae.

Taurolidine at < or = 1,250 micrograms/ml killed all 37 isolates of multiple-antibiotic-resistant Staphylococcus aureus (n = 9), Enterococcus faecium (n = 17), and Enterobacteriaceae (n = 11). Time-kill experiments disclosed that bovine serum (65% v/v) only marginally retarded the bactericidal activity of 2,000 and 1,000 micrograms/ml of taurolidine against the various strains. Taurolidine at 2,000 micrograms/ml did not antagonize the bactericidal activity of 50% (v/v) fresh human serum against promptly and delayed serum-sensitive test strains of Escherichia coli and Serratia marcescens. In the presence of 65% (v/v) of fresh defibrinated human blood from two donors, however, the bactericidal activity of this antimicrobial compound was delayed, i.e., manifested only following extended (overnight) incubation, against staphylococcal and enterococcal isolates, though less so in the case of Enterobacteriaceae. Taurolidine at 2,000 micrograms/ml killed ingested, i.e., intraphagocytic bacteria of human-serum-resistant S. marcescens strains CDC 06:H3 and P016:H-.

Anti-Bacterial Agents↗

PubMedDate not supplied

Antibiotic susceptibility tests with fastidious and nonfastidious bacterial reference strains: effects of aerobic versus hypercapnic incubation.

Representative antimicrobial drugs were examined under aerobic and hypercapnic (3 and 5% v/v CO2) incubation with the Bauer-Kirby agar disk diffusion, a broth microdilution method, and the agar dilution procedure against nonfastidious, standard ATCC quality control strains and against two beta-hemolytic streptococcal, two pneumococcal, and three Haemophilus influenzae ATCC strains. It was found that an atmosphere of 3-5% CO2 merely antagonized amikacin, gentamicin, and netilmicin; the activity of penicillin G was antagonized only against Staphylococcus aureus ATCC 29213 in broth media, but not against any of the other strains. The activity of teicoplanin, and less so that of vancomycin, was enhanced only against S. aureus strain ATCC 25923, but not against the other strains. It was concluded that susceptibility tests, excluding aminoglycoside antibiotics, of beta-hemolytic streptococci, pneumococci, and H. influenzae and H. parainfluenzae should be incubated under 3% (candle jar or incubator) or 5% CO2 (incubator) so as to ensure optimal growth of capnephilic strains and thus avoid potentially misleading large inhibition zones of deceptively low minimal inhibitory concentrations.

Aerobiosis↗

PubMedDate not supplied

Exposure of clinical isolates of Acinetobacter baumannii and genospecies 3 to defibrinated human blood with and without added human 'natural' or (patient) immune antibodies.

Fresh defibrinated blood (65% v/v) from 2 human donors failed to completely kill strains of Acinetobacter baumannii and genospecies 3, representing four serovars each. Although colony counts were reduced > or = 90%, there invariably occurred rebound growth following extended incubation. Neither selected serovar-specific or isolate-homologous (following experimental bacteremia) rabbit immune sera nor three intravenously applicable IgG preparations augmented the bactericidal activity of human blood against six selected strains of A. baumannii and genospecies 3, despite documented antibody contents of all sera and IgG preparations employed. The majority of the sera from 22 patients who were early reconvalescent from systemic infection due to A. baumannii or genospecies 3, showed raised IgM antibody titers, and all sera demonstrated markedly elevated IgG antibody titers as determined with an enzyme-linked immunoassay. Defibrinated blood from donors B and T failed to completely kill the bacteria inocula of these 22 Acinetobacter isolates. Only one patient serum enhanced the bactericidal activity of human blood in the absence of antimicrobial drug(s), and only 1 patient serum with large amounts of detectable antimicrobial drug(s) effected complete killing of the homologous bacterial inoculum.

Acinetobacter↗

PubMedDate not supplied

Piperacillin tazobactam compared with co-amoxiclav, ampicillin plus sulbactam and timentin against beta-lactamase-producing clinical isolates of Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca.

A total of 266 enterobacterial isolates (Escherichia coli = 190, Klebsiella pneumoniae = 49, K. oxytoca = 27) were tested for susceptibility (Bauer-Kirby agar disk diffusion test and agar dilution procedure) to ampicillin, ampicillin in 10 micrograms/ml of sulbactam, amoxicillin in 4 micrograms/ml of clavulanic acid, piperacillin, piperacillin plus tazobactam (8:1 ratio), ticarcillin and timentin (ticarcillin in 4 micrograms/ml of clavulanic acid). Discrepant results between the two methods of susceptibility testing were categorized as follows: category I = very major [minimal inhibitory concentration (MIC) = resistant, disk diffusion = susceptible] category II = major (MIC = susceptible, disk diffusion = resistant), category III = minor (MIC = intermediate susceptibility, disk diffusion = susceptible), category IV = slight (MIC = resistant, disk diffusion = intermediate), category V = minimal (MIC = susceptible, disk diffusion = intermediate) and category VI = negligible (MIC = intermediate, disk diffusion = resistant). The antibiotics, or combinations with beta-lactamase inhibitors, yielded the following discrepant results: ampicillin (II = 2, V = 1 and VI = 3), co-amoxiclav (I = 5, III = 25, IV = 1 and V = 3), ampicillin plus sulbactam (I = 5, II = 3, III = 1, V = 19 and VI = 1), piperacillin (II = 15, III = 1, V = 15 and VI = 85), piperacillin plus tazobactam (III = 16, IV = 2, V = 1 and VI = 5) and timentin (I = 2, III = 48 and IV = 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Amoxicillin↗

PubMedDate not supplied

Comparison of Wilkins-Chalgren medium supplemented with nicotinamide adenine dinucleotide and Haemophilus test medium for susceptibility testing of clinical Haemophilus isolates.

Haemophilus test medium (HTM) was compared with Wilkins-Chalgren agar (WCA; supplemented with 15 micrograms/ml nicotinamide adenine dinucleotide (NAD)) for antibiotic susceptibility testing of 74 clinical isolates of Haemophilus influenzae and Haemophilus parainfluenzae. The Bauer-Kirby agar disk diffusion method and the agar dilution procedure were the two tests employed. WCA + NAD and HTM yielded comparable results for the following antimicrobial drugs and drug combinations: ampicillin, amoxicillin plus clavulanic acid, ampicillin plus sulbactam, cefotaxime, cefuroxime, chloramphenicol, ciprofloxacin, and doxycycline. However, WCA + NAD slightly antagonized rifampin. Co-trimoxazole was significantly antagonized by WCA + NAD. WCA + NAD was much simpler with regard to in-house preparation, and WCA plates could be supplemented with NAD following pouring, solidification and storage of the plates simply by surface spreading the required amount of NAD with a glass spatula, thus adding considerably to laboratory flexibility. It is suggested that additional laboratories comparatively and critically examine WCA + NAD medium for antibiotic susceptibility testing of clinical Haemophilus isolates.

Culture Media↗

PubMedDate not supplied

Gentamicin- and methicillin-resistant Staphylococcus aureus: phenotypic and genotypic characterization of three putative nosocomial outbreak strains.

Nineteen representative isolates of gentamicin- and methicillin-resistant Staphylococcus aureus (MRSA) were found to comprise three phenotypes; these differed with regard to hydrolysis of nitrocefin and production of staphylococcal enterotoxin A or/and toxic shock syndrome toxin-1. All MRSA isolates produced a capsule and were susceptible to coumermycin, nitrofurantoin, novobiocin, trimethoprim, trimethoprim-sulfamethoxazole, teicoplanin and vancomycin. All MRSA isolates were resistant to co-amoxiclav, ciprofloxacin, clarithromycin, gentamicin, methicillin, norfloxacin, ofloxacin, oxacillin and polymyxin B.

Anti-Bacterial Agents↗

PubMedDate not supplied

Immunobiology of methicillin-resistant Staphylococcus aureus: immune response of rabbits and patients to systemic infection.

Teichoic acid (TA) and peptidoglycan (PG) extracted from Staphylococcus aureus strains ATCC 25923 and Lafferty as well as formalinized cells of these two strains and several clinical methicillin-resistant S. aureus (MRSA) isolates were immunogenic for New Zealand White rabbits. Rabbits which had recovered from experimental bacteremia due to MRSA seroconverted, i.e. demonstrated raised titers of antibodies against TA and PG of the S. aureus strain Lafferty and against whole cells (WC) and ultrasound cell lysates (UCL) of MRSA isolates No. 1 and 2 (representative of nosocomial MRSA strain I), as determined with enzyme-linked immunosorbent assays. Furthermore, sera from 2 long-term survivor rabbits recognized four polypeptides (apparent molecular weight = 38.9, 33.9, 30.9, and 28.2 kDa) shared by UCL extracts from MRSA isolates No. 1 and 2, as determined with immunoblots. Neither normal nor immune rabbit sera augmented the bactericidal activity of fresh defibrinated human blood (65% v/v) against selected MRSA isolates and S. aureus strain ATCC 25923. Sera from 12 patients with documented systemic infection due to MRSA outbreak strain I were examined for IgM and IgG antibodies against TA, WC, and UCL antigens. Three patient sera exhibited raised IgM antibodies against TA; 7 of 12 patient sera showed increased IgG anti-TA titers. Only 1 patient had a markedly raised IgM anti-WC titer, whereas 4 and 10 of the patients had increased IgG titers against WC from MRSA isolates No. 1 and 2, respectively. However, all 12 patients had raised IgG titers against UCL from MRSA isolate No.2 versus 4 of 12 patients with elevated IgG titers against UCL from MRSA isolate No.1. Immunoblots with 3 selected patient sera revealed IgG antibodies to be more multifaceted than IgM antibodies. Sera from 11 of the 12 patients contained antimicrobial drug(s); yet only 5 of these 11 sera (used at 10% v/v in broth) killed inocula of MRSA isolate No. 43. None of the 12 patient sera (10% v/v) enhanced the bactericidal activity of human blood against selected MRSA isolates. Neither three commercial intravenously applicable IgG preparations nor an IgG anti-alpha-hemolysin formulation (employed at 10% v/v) augmented the bactericidal activity of fresh defibrinated human blood against selected MRSA isolates comprising MRSA outbreak strain I.

Animals↗

PubMedDate not supplied

Antibiotic susceptibility of clinical isolates of Streptococcus pneumoniae.

Ninety-three representative, recent clinical isolates of Streptococcus pneumoniae were examined for susceptibility to 9 antimicrobial drugs utilizing Mueller-Hinton agar (MHA) enriched with sheep blood and a hypercapnic atmosphere of incubation. One isolate was resistant to penicillin G (minimum inhibitory concentration, MIC = 2 micrograms/ml) and 6 isolates were of intermediate susceptibility to penicillin G (MICs = 0.125-0.25 microgram/ml). The penicillin-G-resistant isolate was also resistant to cefuroxime (MIC = 4 micrograms/ml) and of intermediate susceptibility to cefotaxime (MIC = 1 microgram/ml). This isolate was resistant to chloramphenicol (MIC = 16 micrograms/ml) as well. All 93 isolates were susceptible to teicoplanin and vancomycin. Two isolates each were resistant (MICs = 16 micrograms/ml) or moderately susceptible (MICs = 8 micrograms/ml) to chloramphenicol. Eight isolates were resistant to doxycycline (MICs > or = 8 micrograms/ml), whereas 2 isolates were of intermediate susceptibility to this antibiotic (MICs = 4 micrograms/ml). Three isolates were resistant to erythromycin (MICs > or = 4 micrograms/ml), and 2 isolates showed reduced susceptibility to erythromycin (MICs = 2 micrograms/ml). Chocolatized MHA antagonized the activity of teicoplanin and vancomycin against pneumococcal isolates. Haemophilus test and Wilkins-Chalgren media failed to support optimal growth of all pneumococcal isolates.

Anti-Bacterial Agents↗

PubMedDate not supplied

Antagonism of teicoplanin and vancomycin activity by chocolatized Mueller-Hinton agar.

Chocolatized (80 degrees C, 13 min) Mueller-Hinton agar antagonized the inhibitory activities of teicoplanin and vancomycin against reference strains of Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Staphylococcus aureus, and Enterococcus faecalis. This antagonism was due to heat-exposed sheep erythrocytes, sheep hemoglobin, and the supernatant fluid from lysed sheep erythrocytes, but not to sheep serum. Neither water-soluble cholesterol, bovine albumin, bovine serum, hematin, hemin nor egg yolk suspension antagonized teicoplanin and vancomycin.

Agar↗

PubMedDate not supplied

Comparative susceptibility of clinical group A, B, C, F, and G beta-hemolytic streptococcal isolates to 24 antimicrobial drugs.

A total of 312 clinical beta-hemolytic streptococcal isolates (Streptococcus pyogenes, group A = 63; Streptococcus agalactiae, group B = 145; group C = 50; group F = 27; group G = 27) were examined for susceptibility to 23 and 24 antimicrobial drugs with the Bauer-Kirby agar disk diffusion and the agar dilution method, respectively. Sheep blood Mueller-Hinton agar served as the reference medium. Wilkins-Chalgren agar supported optimal growth of group A and B, but not of all group C, F, and G streptococci. The group A streptococci were susceptible to all beta-lactam antibiotics, clindamycin, chloramphenicol, rifampin, teicoplanin, and vancomycin, but resistant to cotrimoxazole, fusidic acid, and, except for 2 strains, to fosfomycin. Resistance (R)/intermediate susceptibility (I) rates (R/I%) to ciprofloxacin (0/2%), ofloxacin (1/2%), erythromycin (1.6/0%), and clarithromycin (0/1%) were low. Higher resistance rates were noted with tetracyclines (doxycycline 23.8/15.9%; tetracycline 39.7/3.2%). Among the group B streptococcal isolates, one strain was resistant against oxacillin and of intermediate susceptibility to penicillin G and cefoxitin. All isolates were susceptible to teicoplanin and rifampin. Conversely, all group B isolates were resistant to cotrimoxazole and fusidic acid; 69% and 51% of these isolates were susceptible to fosfomycin and rifampin, respectively. R/I rates of the group B streptococcal isolates were low for ciprofloxacin and ofloxacin (0/0.7%), clindamycin (0.7/0%), erythromycin (1.4/ 3.5%), clarithromycin (1.4/0%), and chloramphenicol (0.7/0%). Resistance to tetracyclines was significant (doxycycline: 72.4/2.1%; tetracycline; 74.5/1.4%). Among the non-A, non-B beta-hemolytic streptococci, 2 group C strains were resistant to oxacillin and showed intermediate susceptibility to penicillin G. All isolates were susceptible to third and fourth-generation cephalosporins, imipenem, chloramphenicol, rifampin, teicoplanin, and vancomycin. R/I rates to the other antimicrobial drugs were: ciprofloxacin (3.9/1.9%), ofloxacin (2.9/1.9%), clindamycin (2.9/1%), erythromycin (5.8/0%), clarithromycin (3.8/2.9%), and cotrimoxazole (16.4/3.9%). Resistance against tetracyclines was more frequent (doxycycline: 18.3/2.9%; tetracycline: 20.2/6.7%). On the basis of various minor discrepancies between MIC and disk diffusion test results, it is proposed that the current NCCLS inhibition zone (diameter, mm) criteria indicative of intermediate susceptibility of beta-hemolytic streptococci be changed for the following antimicrobial drugs: ampicillin: 22-27 mm (only for group A and B beta-hemolytic streptococci); ciprofloxacin: 16-18 mm; clindamycin: 15-18 mm; doxycycline: 17-19 mm; tetracycline: 17-19 mm, and erythromycin: 14-19 mm.

Anti-Bacterial Agents↗

PubMedDate not supplied

Antibiotic susceptibility of alpha- and nonhemolytic streptococci from patients and healthy adults to 24 antimicrobial drugs.

A total of 278 alpha- and nonhemolytic streptococcal isolates (patients, n = 116; healthy adults, n = 162) were examined for susceptibility to 23 and 24 antimicrobial drugs with the Bauer-Kirby agar disk diffusion and the agar dilution method, respectively. Wilkins-Chalgren medium compared favorably with sheep blood Mueller-Hinton agar, the reference medium, for 58 representative streptococcal isolates. In terms of minimal inhibitory concentrations (MICs), all 278 isolates were susceptible to teicoplanin and vancomycin. None of the isolates revealed high-level gentamicin resistance. All isolates were resistant to fusidic acid. Twelve Streptococcus mitis isolates, all from patients, were resistant to penicillin G and variably to other antibiotics. Oxacillin disks failed to predict penicillin G susceptibility. In general, patient isolates were more frequently resistant to beta-lactam antibiotics and fluoroquinolones; conversely, isolates from healthy carriers were slightly more resistant to macrolide antibiotics. Specifically, susceptibility rates were: penicillin G 79.1%, oxacillin 87.8%, ampicillin 66.9%, piperacillin 98.2%, cefoxitin 76.6%, cefuroxime 96.8%, cefotaxime 98.6%, ceftriaxone 98.6%, cefepime 98.6%, impipenem 98.2%, ciprofloxacin 59.7%, ofloxacin 89.2%, doxycycline 65.8%, tetracycline 56.8%, clindamycin 87.8%, erythromycin 59%, clarithromycin 74.9%, chloramphenicol 98.9%, cotrimoxazole 97.9%, rifampin 97.5%, and fosfomycin 2.2%. On the basis of numerous minor discrepancies between disk diffusion and agar dilution test results for certain antibiotics, it is proposed that the current NCCLS inhibition zone (diameter, mm) criteria indicative of intermediate susceptibility of alpha- and nonhemolytic streptococci be changed for the following antimicrobial drugs: ampicillin = I = 22-27 mm; ciprofloxacin = I = 16-18 mm; clindamycin = I = 15-18 mm; doxycycline = I = 17-19 mm; tetracycline = I = 17-19 mm; erythromycin = I = 14-19 mm, and cotrimoxazole = I = 11-13 mm. It is recommended to exclude both cefoxitin and doxycycline (substitute = tetracycline) disks from test batteries for non-group A, B beta-hemolytic and alpha-/nonhemolytic streptococcal isolates.

Adult↗

PubMedDate not supplied

Susceptibility of Moraxella catarrhalis to 21 antimicrobial drugs: validity of current NCCLS criteria for the interpretation of agar disk diffusion antibiograms.

Ninety-four clinical isolates of Moraxella catarrhalis were examined for susceptibility to 21 antimicrobial drugs; 67 isolates (= 71.3%) produced beta-lactamase(s). In terms of antibiotic resistance, the number of isolates resistant to penicillin G, ampicillin, and cotrimoxazole were 56, 32, and 1, respectively. The number of isolates with intermediate susceptibility to penicillin G, ampicillin, ciprofloxacin, ofloxacin, cotrimoxazole, and fosfomycin were 11, 34, 1, 2, 2, and 47, respectively. All 94 isolates proved susceptible to ampicillin + 10 micrograms/ml of sulbactam, amoxicillin + 4 micrograms/ml of clavulanic acid, cefuroxime, cefotaxime, cefepime, cefepime, cefixime, imipenem, meropenem, chloramphenicol, doxycycline, tetracycline, fusidic acid, erythromycin, clarithromycin, and rifampin, as based on currently valid NCCLS criteria, where applicable. There were no very major or major discrepancies between agar dilution and agar disk diffusion test results. There were only a few minor discrepancies between test results, specifically: penicillin G (category IV = 4, category VI = 1); ampicillin (category IV = 4, category V = 1, category VI = 7), amoxicillin + clavulanic acid (category III = 11), cotrimoxazole (category IV = 1, category V = 1, category VI = 1), ciprofloxacin (category V = 1), and ofloxacin (category VI = 2). The sole exception was fosfomycin, with a total of 25 minor discrepancies encountered (category III = 14, category V = 9, category VI = 2). Wilkins-Chalgren agar compared favorably with Mueller-Hinton agar following examination with 11 selected antimicrobial drugs against 31 representative isolates of M. catarrhalis.

Anti-Bacterial Agents↗