Lonks, J. R., Garau, J., Medeiros, A. A.
Macrolide resistance among pneumococci is increasing worldwide and is associated with increasing macrolide use. Recent studies show that use of macrolides and azalides increases nasopharyngeal...
Opal, S. M., Boyce, J. M., Medeiros, A. A., Mayer, K. H., Lyhte, L. W.
Nearly all clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) are heterogeneously resistant and produce β-lactamases which generally are plasmid mediated. In order to study the...
Medeiros, A. A., Hare, R., Papa, E., Adam, C., Miller, G. H.
We studied 192 recent clinical isolates, comprising six species of Gram-negative bacilli resistant either to cefotaxime or latamoxef (Moxalactam), from several hospitals. All isolates were resistant...
A functional classification scheme for beta-lactamases and its correlation with molecular structure.
Firsov, A A, Savarino, D, Ruble, M, Gilbert, D, Manzano, B, Medeiros, A A, ...
The clinical outcome in patients treated with ampicillin-sulbactam may not always be predictable by disc susceptibility testing or with the MIC as determined with a constant level (4 micrograms/ml)...
Rasmussen, B A, Bush, K, Keeney, D, Yang, Y, Hare, R, O'Gara, C, ...
In 1984, a year prior to the U.S. approval of imipenem for clinical use, a wound isolate and a bile isolate of Enterobacter cloacae were obtained from two patients in a California hospital. These...
Firsov, A A, Ruble, M, Gilbert, D, Savarino, D, Manzano, B, Medeiros, A A, ...
To examine the predictable effect of inoculum size on the kinetics of the antimicrobial action of ampicillin-sulbactam, five TEM-1 beta-lactamase-producing Escherichia coli strains were studied in an...
Rasheed, J K, Jay, C, Metchock, B, Berkowitz, F, Weigel, L, Crellin, J, ...
Nine isolates of Escherichia coli were recovered from seven blood cultures over a period of 3 months from a 19-month-old female with aplastic anemia. Initial isolates were susceptible to...
Discrimination of extended-spectrum beta-lactamases by a novel nitrocefin competition assay.
Papanicolaou, G A, Medeiros, A A
We describe a nitrocefin competition assay for determining inhibition profiles as a useful adjunct to existing biochemical methods for the discrimination of beta-lactamases. The hydrolysis rate of...
Rice, L B, Willey, S H, Papanicolaou, G A, Medeiros, A A, Eliopoulos, G M, Moellering, R C, ...
During a 4-month period in late 1988, we isolated ceftazidime-resistant strains of Klebsiella pneumoniae and other members of the family Enterobacteriaceae from 29 patients at a chronic-care facility...
Papanicolaou, G A, Medeiros, A A, Jacoby, G A
Klebsiella pneumoniae isolates from 11 patients at the Miriam Hospital were identified as resistant to cefoxitin and ceftibuten as well as to aztreonam, cefotaxime, and ceftazidime. Resistance could...
Role of beta-lactamase in expression of resistance by methicillin-resistant Staphylococcus aureus.
Of 27 unique clinical isolates of methicillin-resistant Staphylococcus aureus, only 4 were homogeneously resistant, and all 4 produced little or no beta-lactamase. Among heterogeneously resistant...
Molecular epidemiology of OHIO-1 beta-lactamase.
Kron, M A, Shlaes, D M, Currie-McCumber, C, Medeiros, A A
A total of 31 plasmids, all bearing a gene that encodes a novel, plasmid-mediated Richmond-Sykes class III beta-lactamase designated OHIO-1 and a gene that encodes aminoglycoside...
An animal source for the ROB-1 beta-lactamase of Haemophilus influenzae type b.
Medeiros, A A, Levesque, R, Jacoby, G A
The most common cause of ampicillin resistance in Haemophilus influenzae type b is production of TEM-1 beta-lactamase; however, a novel enzyme with a similar substrate profile but a quite different...
Hedges, R W, Medeiros, A A, Cohenford, M, Jacoby, G A
A novel carbenicillin-hydrolyzing beta-lactamase has been discovered in a blood isolate of Aeromonas hydrophila. The enzyme resembles plasmid-determined carbenicillinases in substrate profile but...
Five novel plasmid-determined beta-lactamases.
Medeiros, A A, Cohenford, M, Jacoby, G A
Five novel plasmid-determined beta-lactamases named TLE-1, OXA-4, OXA-5, OXA-6, and OXA-7 were detected in ampicillin-resistant isolates of Escherichia coli and carbenicillin-resistant strains of...
Novel plasmid-mediated beta-lactamase in members of the family Enterobacteriaceae from Ohio.
Shlaes, D M, Medeiros, A A, Kron, M A, Currie-McCumber, C, Papa, E, Vartian, C V
Epidemiologic studies of plasmid-mediated resistance at the Cleveland Veterans Administration Medical Center revealed that related plasmids had disseminated among members of the family...
Vecoli, C, Prevost, F E, Ververis, J J, Medeiros, A A, O'Leary, G P
Plasmid-mediated beta-lactamases from strains of Escherichia coli and Pseudomonas aeruginosa were separated by isoelectric focusing on a 0.8-mm thin-layer agarose gel with a pH gradient of 3.5 to...
Four (5%) of 81 recent isolates of Streptococcus pneumoniae from the blood of adult patients but no isolates from pediatric patients (n = 51) were resistant (MIC, > or = 1 microgram/ml) to...
Emergence and nosocomial transmission of ampicillin-resistant enterococci.
Boyce, J M, Opal, S M, Potter-Bynoe, G, LaForge, R G, Zervos, M J, Furtado, G, ...
Between 1986 and 1988, the incidence of ampicillin-resistant enterococci increased sevenfold at a university-affiliated hospital. Forty-three patients acquired nosocomial infections with...
Spread of a "Pseudomonas-specific" beta-lactamase to plasmids of enterobacteria.
Medeiros, A A, Hedges, R W, Jacoby, G A
Eleven isolates including Escherichia coli, Salmonella enteritidis, and Shigella sonnei, obtained in Brazil, Hong Kong, Indonesia, Thailand, and the United States, were found to produce...
Characterization of the beta-lactamases of six species of Legionella.
Marre, R, Medeiros, A A, Pasculle, A W
The beta-lactamases of six Legionella species were characterized by isoelectric focusing, gel filtration, and substrate profiles. Fifteen strains of L. bozemanii, L. dumoffii, L. gormanii, L....
Molecular distribution of ROB-1 beta-lactamase in Actinobacillus pleuropneumoniae.
Juteau, J M, Sirois, M, Medeiros, A A, Levesque, R C
The plasmid content and molecular distribution of the ROB-1 beta-lactamase was investigated in 31 swine isolates of Actinobacillus pleuropneumoniae. Three types of plasmid patterns were observed in...
Boyce, J M, Papa, E, Dickenson, R, Medeiros, A A
We tested 75 methicillin-resistant Staphylococcus aureus strains for susceptibility to imipenem by using disk diffusion tests and broth microdilution tests with standard and heavy inocula. Population...
Boyce, J M, Opal, S M, Chow, J W, Zervos, M J, Potter-Bynoe, G, Sherman, C B, ...
Enterococcus faecium strains resistant to ampicillin, high levels of gentamicin, and vancomycin but susceptible to teicoplanin (vanB class vancomycin resistance) were recovered from 37 patients...
Spurious oxacillin resistance in Staphylococcus aureus because of defective oxacillin disks.
Boyce, J M, Lonks, J R, Medeiros, A A, Papa, E F, Campbell, S
Clinical isolates of Staphylococcus aureus wee inappropriately categorized as intermediate or resistant to oxacillin on the basis of tests with two lots of oxacillin disks. The potency of one lot was...
The significance of the intermediate category of the single-disk diffusion test (Kirby-Bauer) of antibiotic susceptibility has never been clearly defined. Thirty-two percent of 756 clinical isolates...
Dissemination of an antibiotic resistance plasmid in hospital patient flora.
O'Brien, T F, Ross, D G, Guzman, M A, Medeiros, A A, Hedges, R W, Botstein, D
The 2'' aminoglycoside nucleotidyltransferase, AAD (2''), which adenylates gentamicin, tobramycin, and kanamycin, became prevalent over several months in multiple strains and species of...
Strayer, A H, Gilbert, D H, Pivarnik, P, Medeiros, A A, Zinner, S H, Dudley, M N
The pharmacodynamics of dosage regimens of piperacillin alone or in combination with tazobactam against piperacillin-resistant or -susceptible bacteria were studied in an in vitro model of infection....
A functional classification scheme for beta-lactamases and its correlation with molecular structure.
Firsov, A A, Savarino, D, Ruble, M, Gilbert, D, Manzano, B, Medeiros, A A, ...
The clinical outcome in patients treated with ampicillin-sulbactam may not always be predictable by disc susceptibility testing or with the MIC as determined with a constant level (4 micrograms/ml)...
Rasmussen, B A, Bush, K, Keeney, D, Yang, Y, Hare, R, O'Gara, C, ...
In 1984, a year prior to the U.S. approval of imipenem for clinical use, a wound isolate and a bile isolate of Enterobacter cloacae were obtained from two patients in a California hospital. These...
Firsov, A A, Ruble, M, Gilbert, D, Savarino, D, Manzano, B, Medeiros, A A, ...
To examine the predictable effect of inoculum size on the kinetics of the antimicrobial action of ampicillin-sulbactam, five TEM-1 beta-lactamase-producing Escherichia coli strains were studied in an...
Rasheed, J K, Jay, C, Metchock, B, Berkowitz, F, Weigel, L, Crellin, J, ...
Nine isolates of Escherichia coli were recovered from seven blood cultures over a period of 3 months from a 19-month-old female with aplastic anemia. Initial isolates were susceptible to...
Discrimination of extended-spectrum beta-lactamases by a novel nitrocefin competition assay.
Papanicolaou, G A, Medeiros, A A
We describe a nitrocefin competition assay for determining inhibition profiles as a useful adjunct to existing biochemical methods for the discrimination of beta-lactamases. The hydrolysis rate of...
Rice, L B, Willey, S H, Papanicolaou, G A, Medeiros, A A, Eliopoulos, G M, Moellering, R C, ...
During a 4-month period in late 1988, we isolated ceftazidime-resistant strains of Klebsiella pneumoniae and other members of the family Enterobacteriaceae from 29 patients at a chronic-care facility...
Papanicolaou, G A, Medeiros, A A, Jacoby, G A
Klebsiella pneumoniae isolates from 11 patients at the Miriam Hospital were identified as resistant to cefoxitin and ceftibuten as well as to aztreonam, cefotaxime, and ceftazidime. Resistance could...
Role of beta-lactamase in expression of resistance by methicillin-resistant Staphylococcus aureus.
Of 27 unique clinical isolates of methicillin-resistant Staphylococcus aureus, only 4 were homogeneously resistant, and all 4 produced little or no beta-lactamase. Among heterogeneously resistant...
Molecular epidemiology of OHIO-1 beta-lactamase.
Kron, M A, Shlaes, D M, Currie-McCumber, C, Medeiros, A A
A total of 31 plasmids, all bearing a gene that encodes a novel, plasmid-mediated Richmond-Sykes class III beta-lactamase designated OHIO-1 and a gene that encodes aminoglycoside...
An animal source for the ROB-1 beta-lactamase of Haemophilus influenzae type b.
Medeiros, A A, Levesque, R, Jacoby, G A
The most common cause of ampicillin resistance in Haemophilus influenzae type b is production of TEM-1 beta-lactamase; however, a novel enzyme with a similar substrate profile but a quite different...
Hedges, R W, Medeiros, A A, Cohenford, M, Jacoby, G A
A novel carbenicillin-hydrolyzing beta-lactamase has been discovered in a blood isolate of Aeromonas hydrophila. The enzyme resembles plasmid-determined carbenicillinases in substrate profile but...
Five novel plasmid-determined beta-lactamases.
Medeiros, A A, Cohenford, M, Jacoby, G A
Five novel plasmid-determined beta-lactamases named TLE-1, OXA-4, OXA-5, OXA-6, and OXA-7 were detected in ampicillin-resistant isolates of Escherichia coli and carbenicillin-resistant strains of...
Novel plasmid-mediated beta-lactamase in members of the family Enterobacteriaceae from Ohio.
Shlaes, D M, Medeiros, A A, Kron, M A, Currie-McCumber, C, Papa, E, Vartian, C V
Epidemiologic studies of plasmid-mediated resistance at the Cleveland Veterans Administration Medical Center revealed that related plasmids had disseminated among members of the family...
Vecoli, C, Prevost, F E, Ververis, J J, Medeiros, A A, O'Leary, G P
Plasmid-mediated beta-lactamases from strains of Escherichia coli and Pseudomonas aeruginosa were separated by isoelectric focusing on a 0.8-mm thin-layer agarose gel with a pH gradient of 3.5 to...
Four (5%) of 81 recent isolates of Streptococcus pneumoniae from the blood of adult patients but no isolates from pediatric patients (n = 51) were resistant (MIC, > or = 1 microgram/ml) to...
Emergence and nosocomial transmission of ampicillin-resistant enterococci.
Boyce, J M, Opal, S M, Potter-Bynoe, G, LaForge, R G, Zervos, M J, Furtado, G, ...
Between 1986 and 1988, the incidence of ampicillin-resistant enterococci increased sevenfold at a university-affiliated hospital. Forty-three patients acquired nosocomial infections with...
Spread of a "Pseudomonas-specific" beta-lactamase to plasmids of enterobacteria.
Medeiros, A A, Hedges, R W, Jacoby, G A
Eleven isolates including Escherichia coli, Salmonella enteritidis, and Shigella sonnei, obtained in Brazil, Hong Kong, Indonesia, Thailand, and the United States, were found to produce...
Characterization of the beta-lactamases of six species of Legionella.
Marre, R, Medeiros, A A, Pasculle, A W
The beta-lactamases of six Legionella species were characterized by isoelectric focusing, gel filtration, and substrate profiles. Fifteen strains of L. bozemanii, L. dumoffii, L. gormanii, L....
Molecular distribution of ROB-1 beta-lactamase in Actinobacillus pleuropneumoniae.
Juteau, J M, Sirois, M, Medeiros, A A, Levesque, R C
The plasmid content and molecular distribution of the ROB-1 beta-lactamase was investigated in 31 swine isolates of Actinobacillus pleuropneumoniae. Three types of plasmid patterns were observed in...
Boyce, J M, Papa, E, Dickenson, R, Medeiros, A A
We tested 75 methicillin-resistant Staphylococcus aureus strains for susceptibility to imipenem by using disk diffusion tests and broth microdilution tests with standard and heavy inocula. Population...
Boyce, J M, Opal, S M, Chow, J W, Zervos, M J, Potter-Bynoe, G, Sherman, C B, ...
Enterococcus faecium strains resistant to ampicillin, high levels of gentamicin, and vancomycin but susceptible to teicoplanin (vanB class vancomycin resistance) were recovered from 37 patients...
Spurious oxacillin resistance in Staphylococcus aureus because of defective oxacillin disks.
Boyce, J M, Lonks, J R, Medeiros, A A, Papa, E F, Campbell, S
Clinical isolates of Staphylococcus aureus wee inappropriately categorized as intermediate or resistant to oxacillin on the basis of tests with two lots of oxacillin disks. The potency of one lot was...
The significance of the intermediate category of the single-disk diffusion test (Kirby-Bauer) of antibiotic susceptibility has never been clearly defined. Thirty-two percent of 756 clinical isolates...
Dissemination of an antibiotic resistance plasmid in hospital patient flora.
O'Brien, T F, Ross, D G, Guzman, M A, Medeiros, A A, Hedges, R W, Botstein, D
The 2'' aminoglycoside nucleotidyltransferase, AAD (2''), which adenylates gentamicin, tobramycin, and kanamycin, became prevalent over several months in multiple strains and species of...
Strayer, A H, Gilbert, D H, Pivarnik, P, Medeiros, A A, Zinner, S H, Dudley, M N
The pharmacodynamics of dosage regimens of piperacillin alone or in combination with tazobactam against piperacillin-resistant or -susceptible bacteria were studied in an in vitro model of infection....