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Antimicrobial Agents and Chemotherapy Nov 1979The agar disk diffusion susceptibility of Enterobacteriaceae to mezlocillin and piperacillin was correlated with agar minimal inhibitory concentrations and compared with...
The agar disk diffusion susceptibility of Enterobacteriaceae to mezlocillin and piperacillin was correlated with agar minimal inhibitory concentrations and compared with the susceptibility to carbenicillin. The agar disk susceptibility of Pseudomonas aeruginosa to azlocillin, mezlocillin, and piperacillin was correlated with agar minimal inhibitory concentrations and compared with the susceptibility to carbenicillin and ticarcillin. Criteria are offered for the zones of inhibition to provide information about resistant and susceptible isolates that correlate with known serum levels.
Topics: Carbenicillin; Enterobacteriaceae; Escherichia coli; Microbial Sensitivity Tests; Penicillins; Pseudomonas aeruginosa; Ticarcillin
PubMed: 118706
DOI: 10.1128/AAC.16.5.625 -
Antimicrobial Agents and Chemotherapy Jan 1977Mezlocillin is a new semisynthetic penicillin that inhibited 71% of the isolates of Serratia marcescens, 67% of Escherichia coli, 50% of Enterobacter spp., and 49% of... (Comparative Study)
Comparative Study
Mezlocillin is a new semisynthetic penicillin that inhibited 71% of the isolates of Serratia marcescens, 67% of Escherichia coli, 50% of Enterobacter spp., and 49% of Klebsiella spp. at a concentration of 12.5 mug/ml. It is also active against both indole-positive and -negative Proteus spp. and gram-positive cocci, except penicillin G-resistant Staphylococcus aureus. At a concentration of 100 mug/ml, it inhibited 94% of the isolates of Pseudomonas aeruginosa. It is more active than ampicillin, carbenicillin, and cephalothin against some gram-negative bacilli.
Topics: Bacteria; Chemical Phenomena; Chemistry; Drug Evaluation, Preclinical; Penicillins; Species Specificity
PubMed: 836016
DOI: 10.1128/AAC.11.1.74 -
PloS One 2014The clinical relevance of nosocomially acquired infections caused by multi-resistant Achromobacter strains is rapidly increasing. Here, a diverse set of 61 Achromobacter...
The clinical relevance of nosocomially acquired infections caused by multi-resistant Achromobacter strains is rapidly increasing. Here, a diverse set of 61 Achromobacter xylosoxidans strains was characterized by MultiLocus Sequence Typing and Phenotype MicroArray technology. The strains were further analyzed in regard to their susceptibility to 35 antibiotics and to 34 different and newly isolated bacteriophages from the environment. A large proportion of strains were resistant against numerous antibiotics such as cephalosporines, aminoglycosides and quinolones, whereas piperacillin-tazobactam, ticarcillin, mezlocillin and imipenem were still inhibitory. We also present the first expanded study on bacteriophages of the genus Achromobacter that has been so far a blank slate with respect to phage research. The phages were isolated mainly from several waste water treatment plants in Germany. Morphological analysis of all of these phages by electron microscopy revealed a broad diversity with different members of the order Caudovirales, including the families Siphoviridae, Myoviridae, and Podoviridae. A broad spectrum of different host ranges could be determined for several phages that lysed up to 24 different and in part highly antibiotic resistant strains. Molecular characterisation by DNA restriction analysis revealed that all phages contain linear double-stranded DNA. Their restriction patterns display distinct differences underlining their broad diversity.
Topics: Achromobacter denitrificans; Anti-Bacterial Agents; Blotting, Southern; Caudovirales; Drug Resistance, Bacterial; Germany; Microarray Analysis; Microscopy, Electron; Multilocus Sequence Typing; Phylogeny; Polymorphism, Restriction Fragment Length; Species Specificity
PubMed: 24466294
DOI: 10.1371/journal.pone.0086935 -
Medicine Jun 2020Methicillin-resistant Staphylococcus aureus (MRSA) has been established as an important cause of severe community-acquired pneumonia (CAP) with very high mortality....
RATIONALE
Methicillin-resistant Staphylococcus aureus (MRSA) has been established as an important cause of severe community-acquired pneumonia (CAP) with very high mortality. Panton-Valentine leukocidin (PVL) producing MRSA has been reported to be associated with necrotizing pneumonia and worse outcome. The incidence of community-acquired MRSA (CA-MRSA) pneumonia is very low, as only a few CA-MRSA pneumonia cases were reported in the last few years. We present a case of severe CAP caused by PVL-positive MRSA with ensuing septic shock.
PATIENT CONCERNS
A 68-year-old male with no concerning medical history had developed a fever that reached 39.0°C, a productive cough that was sustained for 5 days, and hypodynamia. He was treated with azithromycin and alexipyretic in a nearby clinic for 2 days in which the symptoms were alleviated. However, 1 day later, the symptoms worsened, and he was taken to a local Chinese medicine hospital for traditional medicine treatment. However, his clinical condition deteriorated rapidly, and he then developed dyspnea and hemoptysis.
DIAGNOSIS
CA-MRSA pneumonia and septic shock. The sputum culture showed MRSA. Polymerase chain reaction of MRSA isolates was positive for PVL genes.
INTERVENTIONS
Mechanical ventilation, fluid resuscitation, and antibiotic therapy were performed. Antibiotic therapy included mezlocillin sodium/sulbactam sodium, linezolid, and oseltamivir.
OUTCOMES
He died after 12 hours of treatment.
LESSONS
This is a report of severe pneumonia due to PVL-positive CA-MRSA in a healthy adult. CA-MRSA should be considered a pathogen of severe CAP, especially when combined with septic shock in previously healthy individuals.
Topics: Aged; Anti-Bacterial Agents; Cough; Healthcare-Associated Pneumonia; Humans; Hypokinesia; Linezolid; Male; Methicillin-Resistant Staphylococcus aureus; Mezlocillin; Oseltamivir; Shock, Septic; Staphylococcal Infections
PubMed: 32590802
DOI: 10.1097/MD.0000000000020914 -
Antimicrobial Agents and Chemotherapy Jan 1985Diffusion rates of various beta-lactam antibiotics through the OmpF and OmpC porin channels of Escherichia coli K-12 were measured by the use of reconstituted...
Diffusion rates of various beta-lactam antibiotics through the OmpF and OmpC porin channels of Escherichia coli K-12 were measured by the use of reconstituted proteoliposomes. The results can be interpreted on the basis of the gross physicochemical properties of the antibiotics along the following lines. (i) As noted previously (Nikaido et al., J. Bacteriol., 153:232-240, 1983), there was a monotonous dependence of the penetration rate on the hydrophobicity of the molecule among the classical monoanionic beta-lactams, and a 10-fold increase in the octanol-water partition coefficient of the uncharged molecule decreased the penetration rate by a factor of 5 to 6. (ii) Compounds with exceptionally bulky side chains, such as mezlocillin, piperacillin, and cefoperazone, showed much slower penetration rates than expected from their hydrophobicity. (iii) The substituted oxime side chain on the alpha-carbon of the substituent group at position 7 of the cephem nucleus decreased the penetration rate almost by an order of magnitude; this appears to be largely due to the steric effect. (iv) The presence of a methoxy group at position 7 of the cephalosporins also reduced the penetration rate by 20%, probably also due to the steric hindrance. (v) Zwitterionic compounds penetrated very rapidly, and the correlation between the rate and hydrophobicity appeared to be much weaker than with the monoanionic compounds. Imipenem showed the highest permeability among the compounds tested, presumably due, at least in part, to its compact molecular structure. (vi) Compounds with two negative charges penetrated more slowly than did analogs with only one negatively charged group. Among them, only moxalactam, ceftriaxone, and azthreonam showed penetration rates corresponding to, or higher than, 10% of that of imipenem.
Topics: Anti-Bacterial Agents; Bacterial Outer Membrane Proteins; Chemical Phenomena; Chemistry, Physical; Diffusion; Escherichia coli; Ion Channels; Liposomes; Permeability; Porins; beta-Lactams
PubMed: 2580479
DOI: 10.1128/AAC.27.1.84 -
The Yale Journal of Biology and Medicine 1986Fifty-three clinical isolates of Klebsiella and fifty-one clinical isolates of Pseudomonas aeruginosa, twenty-six of which were carbenicillin-(CARB) resistant, were... (Comparative Study)
Comparative Study
Fifty-three clinical isolates of Klebsiella and fifty-one clinical isolates of Pseudomonas aeruginosa, twenty-six of which were carbenicillin-(CARB) resistant, were tested for susceptibility to mezlocillin (MEZ), azlocillin (AZL), and piperacillin (PIP), both alone and in combination with tobramycin (TOB) using the microtiter broth diluent method and an inoculum density of 10(6) CFU/ml. The Klebsiella were highly resistant to TOB, MEZ, and PIP (MIC90: 8, greater than 256, greater than 128 micrograms/ml, respectively). Synergy was demonstrated in 53 percent (PIP/TOB) and 51 percent (MEZ/TOB). An indifferent response was observed in 47 percent (PIP/TOB) and 49 percent MEZ/TOB of the Klebsiella. PIP, MEZ, and AZL in combination with TOB showed synergism against CARB-resistant Pseudomonas in less than 10 percent of the strains tested. Synergy could be demonstrated against CARB-susceptible Pseudomonas with the combinations PIP/TOB, AZL/TOB, and MEZ/TOB in 12 percent, 12 percent, and 24 percent, respectively, of the twenty-five strains tested. Indifferent effects were observed in 84 percent, 88 percent, and 76 percent, respectively, of these same CARB-susceptible strains. These data suggest that there is no significant difference in the incidence of synergy with these new penicillins and tobramycin against either Pseudomonas or Klebsiella.
Topics: Azlocillin; Carbenicillin; Drug Combinations; Drug Synergism; In Vitro Techniques; Klebsiella; Mezlocillin; Penicillin Resistance; Piperacillin; Pseudomonas; Tobramycin
PubMed: 3634545
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Dec 1980In vitro properties of 19 antimicrobial agents were tested with 56 isolates of Klebsiella spp. The aminoglycosides and the new beta-lactam compounds cefotaxime and...
In vitro properties of 19 antimicrobial agents were tested with 56 isolates of Klebsiella spp. The aminoglycosides and the new beta-lactam compounds cefotaxime and moxalactam were the most inhibitory drugs tested. Chloramphenicol, tetracycline, trimethoprim, and trimethoprim-sulfamethoxazole were moderately active, whereas piperacillin, mezlocillin, and furazlocillin were ineffective against 25% of the isolates. Gentamicin was the only agent tested that was uniformly bactericidal in time-kill experiments with drug concentrations of four times the minimal inhibitory concentration. In combination studies with gentamicin, moxalactam and furazlocillin each increased the rate of bacterial killing for three of five isolates as compared with gentamicin alone, whereas chloramphenicol significantly retarded the rate of bacterial killing for the same number of strains. Furazlocillin was completely inactivated after 24 h of incubation with each of five selected strains. The inactivation of moxalactam, cefoxitin, and cephalothin was 36, 56, and 72%, respectively. In all instances in which these four agents were inactivated to levels below the minimal bactericidal concentration, there was accelerated growth after initial inhibition. However, regrowth also occurred in three instances in which drug levels were higher than the minimal bactericidal concentration. Retesting after drug exposure revealed a 4- to 32-fold rise in the minimal inhibitory concentration and minimal bactericidal concentration in two of these isolates.
Topics: Anti-Bacterial Agents; Bacterial Infections; Drug Synergism; Drug Therapy, Combination; Humans; Inactivation, Metabolic; Kinetics; Klebsiella; Microbial Sensitivity Tests; Time Factors
PubMed: 7235676
DOI: 10.1128/AAC.18.6.877 -
Antimicrobial Agents and Chemotherapy Jun 1982We assessed the extent and mechanisms of antagonism of beta-lactam antibiotics by cefoxitin. In tests with 41 gram-negative isolates, cefoxitin antagonized cephalothin,...
We assessed the extent and mechanisms of antagonism of beta-lactam antibiotics by cefoxitin. In tests with 41 gram-negative isolates, cefoxitin antagonized cephalothin, cefamandole, cefsulodin, cefotaxime, moxalactam, ampicillin, carbenicillin, piperacillin, mezlocillin, and azlocillin, but not cephalexin, mecillinam, or N-formimidoyl thienamycin. The extent of antagonism varied with the beta-lactam and genus studied. However, antagonism occurred most often with strains possessing inducible cephalosporinases. Antagonism of cephalothin and cefamandole correlated closely with the induction of beta-lactamases capable of inactivating these drugs. Although antagonism of the remaining drugs occurred more often with strains possessing inducible beta-lactamases, these enzymes did not inactivate the drugs. Morphological studies revealed that cefoxitin inhibited filamentation and lysis produced by various beta-lactam drugs. Results of this investigation suggest that cefoxitin antagonizes beta-lactams via (i) induction of drug-inactivating beta-lactamases, and (ii) the induction of beta-lactamases that cannot inactivate the drug but serve as barriers against access to target proteins. This barrier appears most efficient for drugs that bind to penicillin-binding proteins 1 and 3.
Topics: Anti-Bacterial Agents; Bacteria; Cefoxitin; Microbial Sensitivity Tests; beta-Lactamases; beta-Lactams
PubMed: 6981376
DOI: 10.1128/AAC.21.6.968 -
The New Microbiologica Jan 2009A total of 57 Aeromonas isolates from food samples such as fresh and frozen chicken, game birds, pasteurized milk, baby food, bakery products, fruit and vegetables,...
A total of 57 Aeromonas isolates from food samples such as fresh and frozen chicken, game birds, pasteurized milk, baby food, bakery products, fruit and vegetables, fish, and water from Abu Dahbi, UAE were investigated for antibiotic susceptibility profile. Most strains were resistant to penicillins (ticarcillin, mezlocillin, oxacillin, piperacillin), sulfamethoxazole, trimethoprim and macrolides (erythromycin, vancomycin, clindamycin) but sensitive to tetracycline, chloramphenicol, nitrofurantoin, aminoglycosides (amikacin, gentamicin, tobramycin), cephalosporins (cefuroxime, ceftrioxone, cefazolin, cephalexin, cephalothin, cefoxitin, cefotaxime), quinolone (ciprofloxacin), colistin sulphate and SXT (trimethoprim-sulfamethoxazole). On the other hand, many antibiotics showed excellent inhibitory activity (>75% strains were sensitive to them) against all the strains tested. These include cefuroxime, ceftrioxone, ciprofloxacin, colistin, amikacin, gentamicin, tetracycline, chloramphenicol, nitrofurantoin, cefotaxime and tobramycin. In conclusion, the results show a detailed pattern of sensitivity of the various Aeromonas spp. isolates to a variety of antibiotics and provide useful information in the context of selective isolation and phenotypic identification of the aeromonads from food.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Food Microbiology; Humans; Microbial Sensitivity Tests; Species Specificity; United Arab Emirates; Water Microbiology
PubMed: 19382665
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Dec 1978Mezlocillin in doses of 1.0, 2.0, and 5.0 g and carbenicillin in doses of 2.0 g were given as bolus injections intravenously to 10 healthy volunteers. For mezlocillin,...
Mezlocillin in doses of 1.0, 2.0, and 5.0 g and carbenicillin in doses of 2.0 g were given as bolus injections intravenously to 10 healthy volunteers. For mezlocillin, dose-dependent pharmacokinetics was detected. This is reflected by a more than proportional rise in serum concentrations and a decreased total body clearance as doses were increased. Per dose unit, the areas under serum concentration curves to infinity were 33.5 mug.h/ml for the 1.0-g dose, 47.2 mug.h/ml for the 2.0-g dose, and 54.8 mug.h/ml for the 5.0-g dose. The body clearance fell from 31.2 liters/h with the 1.0-g dose to 17.0 liters/h with the 5.0-g dose. This can be explained mainly by a marked depression of nonrenal clearance, which fell from 12.2 to 3.8 liters/h, compared with a parallel change in renal clearance from 19.0 to 13.2 liters/h. Contributing to the non-linearity may be biotransformation, evacuation via bile, or another process. With dose increments, rising amounts are recovered unchanged in the urine-61% after a 1.0-g dose compared with 69% after a 5.0-g dose. This clearly defines metabolism as a major factor of elimination. Carbenicillin, for which the first-order, two-compartment open model was applicable here as in previous studies, had a longer serum half-life than did mezlocillin. For the 2.0-g doses, the former had a half-life of 1.4 h, compared with 0.8 h for the latter (calculated as if the two-compartment model were fully valid). The relative area under the curve (see above) was 76.1 mug.h/ml after the 2.0-g dose.
Topics: Adult; Drug Evaluation; Humans; Injections, Intravenous; Penicillins
PubMed: 742869
DOI: 10.1128/AAC.14.6.801