scholarly journals Evolution and resistance expression of MRSA. Evaluation of beta-lactam antibiotics against a set of isogenic strains with different types of phenotypic expression.

1995 ◽  
Vol 42 (4) ◽  
pp. 517-524 ◽  
Author(s):  
K Asada ◽  
Y Inaba ◽  
E Tateda-Suzuki ◽  
K Kuwahara-Arai ◽  
T Ito ◽  
...  
Keyword(s):  
Meca Gene ◽  
Phenotypic Expression ◽  
Aminoglycoside Antibiotic ◽  
Penicillin G ◽  
Binding Affinities ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Mrsa Infection ◽  
Resistance Expression

Methicillin-resistant Staphylococcus aureus (MRSA) has two mechanisms of resistance to beta-lactam antibiotics; one is mediated by mecA gene expression, and the other by penicillinase production. It has been generally accepted in the clinical field that beta-lactam antibiotics are not the drugs of choice for MRSA infection. In this report, however, ampicillin and penicillin G were shown to have relatively good activity against MRSA if combined with a beta-lactamase inhibitor, sulbactam. These beta-lactam antibiotics were found to have relatively high binding affinities to PBP2', the mecA-encoded MRSA-specific penicillin-binding protein. The possible therapeutic application of sulbactam/ampicillin against MRSA infection in combination with arbekacin, an aminoglycoside antibiotic newly developed and introduced into clinical use in Japan, is discussed.

scholarly journals A metallo-beta-lactamase with both beta-lactamase and ribonuclease activity is linked with traduction in giant viruses

2019 ◽  
Author(s):  
Philippe Colson ◽  
Lucile Pinault ◽  
Said Azza ◽  
Nicholas Armstrong ◽  
Eric Chabriere ◽  
...  
Keyword(s):  
Acanthamoeba Castellanii ◽  
Deep Ocean ◽  
Penicillin G ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Strong Activity ◽  
Beta Lactam Antibiotics ◽  
Double Stranded Dna ◽  
Giant Viruses ◽  
Hydrolysis Of

ABSTRACTEnzymatic proteins with a metallo-beta-lactamase (MBL) fold have been essentially studied in bacteria for their activity on beta-lactam antibiotics. However, the MBL fold is ancient and highly conserved, and these proteins are capable of cleaving a broad range of substrates. It has recently been shown that MBLs are present in a wide array of cellular organisms, including eukaryotes and archaea. We show here that Tupanvirus deep ocean, a giant virus, also encodes a protein with a MBL fold. Phylogeny showed its clustering with transfer ribonucleases (RNases) and the presence of orthologs in other giant viruses, mainly those harboring the largest sets of translation components. In addition, it suggests an ancient origin for these genes and a transfer between giant viruses and Acanthamoeba spp., a host of many giant viruses. Biologically, after its expression in Escherichia coli, the tupanvirus protein was found to hydrolyse nitrocefin, a chromogenic beta-lactam. We also observed an hydrolysis of penicillin G (10 μg/mL) and detected the metabolite of penicillin G hydrolysis, benzylpenilloic acid. This was inhibited by sulbactam, a beta-lactamase inhibitor. In addition, we tested the degradation of single-stranded DNA, double-stranded DNA, and RNAs, and observed a strong activity on RNAs from seven bacteria with G+C varying from 42% to 67%, and from Acanthamoeba castellanii, the tupanvirus host. This was not inhibited by sulbactam or ceftriaxone. RNase activity was estimated to be 0.45±0.15 mU/mg using a fluorescence-based assay. Our results still broaden the range of hosts of MBL fold proteins and demonstrate that such protein can have dual beta-lactamase/nuclease activities. We suggest that they should be annotated according to this finding to avoid further confusion.

scholarly journals Simultaneous Determination of Different Antibiotic Residues in Bovine and in Porcine Kidneys by Solid-Phase Fluorescence Immunoassay

2003 ◽  
Vol 86 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Lieve Okerman ◽  
Katia De Wasch ◽  
Jan Van Hoof ◽  
Walter Smedts
Keyword(s):  
Solid Phase ◽  
Kidney Tissue ◽  
Test System ◽  
Penicillin G ◽  
Fluorescence Immunoassay ◽  
Beta Lactam ◽  
Residue Detection ◽  
Beta Lactam Antibiotics ◽  
Minimal Sample

Abstract Parallux®, a solid-phase fluorescence immunoassay (SPFIA) developed for antibiotic residue detection in milk, was used for analysis of bovine and porcine kidney tissue. Four tetracyclines, 2 broad-spectrum cephalosporins, 3 beta-lactam antibiotics, and cephapirin were detected in one run after minimal sample preparation. This commercially available test system is designed as cartridges, each with a combination of 1–4 tests. One cartridge can be used to detect 4 analytes in the same sample, or 1 or 2 analytes in different samples. The cartridge with the combination tetracyclines–ceftiofur–penicillin–cephapirin was selected because tetracyclines, beta-lactam antibiotics as well as cephalosporins, are registered for oral or parenteral use in bovines and pigs in Europe. The test is qualitative and is recommended only for screening. Tetracycline, oxytetracycline, chlortetracycline, and doxycycline were easily detected at 300 ppb with the tetracyclines channel; ceftiofur at 1000 ppb and cefquinome at 200 ppb with the ceftiofur channel; penicillin G, ampicillin, and amoxicillin at 50 ppb with the penicillin channel; and cephapirin at 100 ppb with the cephapirin channel. These levels are equal to or lower than the corresponding maximal residue limits in kidney tissue. Cephalexin was not detected. The SPFIA test can be used as an alternative to classical inhibition tests and for post-screening inhibitor- positive kidneys, because it detects 3 specific groups of antibiotics, which enables selection of specific confirmatory methods for identification and quantification.

scholarly journals Screening of Milk Borne Staphylococcus aureus for Resistance against Beta Lactam Antibiotics

2020 ◽  
Author(s):  
B. Anurag ◽  
T. Ramasamy ◽  
S. Ramesh ◽  
K.S. Sriraam ◽  
L. Kalaiselvi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Meca Gene ◽  
Antibiotic Sensitivity ◽  
Large Animal ◽  
Beta Lactam ◽  
College Hospital ◽  
Mannitol Salt Agar ◽  
Beta Lactam Antibiotics ◽  
Outpatient Unit ◽  
Sensitivity Pattern

Background: A study was carried out to screen milk borne Staphylococcus aureus for resistance against Beta lactam antibiotics. Methods: A total of 45 milk samples were collected over a period of three months from large animal outpatient unit of Madras Veterinary College Hospital, Chennai. Upon collection of samples, ABST followed by its growth in Mannitol Salt Agar was carried out as part of the phenotypic screening. Genotypic screening for Staphylococcus screening was done with the help of PCR by using nuc and mec A primers. MIC for ceftriaxone and cloxacillin was carried out with the samples that were found positive for Staphylococcus aureus. The antibiotic sensitivity pattern is presented: Fluoroquinolones (87.5% sensitive), aminoglycosides (72.5% sensitive), Amoxicillin-Clavulanic acid (Amoxyclave) (72.5% sensitive). The MSA positive samples were subjected to molecular identification with the help of PCR. Result: The results revealed 10 samples positive for Staphylococcus aureus and 5 among them positive for mecA gene. The MIC results were as follows: MIC50-10.95µg/ml and MIC90- 87.510.95µg/ml for ceftriaxone and MIC50- 43.75 µg/ml and MIC90- 87.5µg/ml for cloxacillin, indicating emergence of resistance. However, further studies are required in a larger sample size that can help us to attain more conclusive results.

scholarly journals Validation Study of a Receptor-Based Lateral Flow Assay for Detection of Beta-Lactam Antibiotics in Milk

2009 ◽  
Vol 92 (3) ◽  
pp. 959-974 ◽  
Author(s):  
Mohamed Abouzied ◽  
Michael Sarzynski ◽  
Aaron Walsh ◽  
Heather Wood ◽  
Mark Mozola
Keyword(s):  
Bovine Milk ◽  
Operating Parameter ◽  
Raw Milk ◽  
Cross Reactivity ◽  
Penicillin G ◽  
Beta Lactam ◽  
Milk Samples ◽  
Beta Lactam Antibiotics ◽  
Cell Counts ◽  
Lactam Antibiotic

Abstract Avalidation study designed tomeet the requirements of the AOAC Research Institute and the U.S. Food and Drug Administration (FDA), Center for Veterinary Medicine, was conducted for a receptor-based, immunochromatographic method (BetaStar US) for detection of beta-lactam antibiotic residues in raw, commingled bovine milk. The assay was found to detect amoxicillin, ampicillin, cephapirin, cloxacillin, and penicillin G at levels below the FDA tolerance/safe levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. Results of the Part I (internal) and Part II (independent laboratory) dose-response studies using spiked samples were in very close agreement for all five drugs tested, with differences between the Part I and Part II 90/95 sensitivity values ranging from 0 to 1 ppb. The test was able to detect all five drugs at the approximate 90/95 sensitivity levels when present as incurred residues in milk collected from cows that had been treated with the specific drug. Asixth drug, ceftiofur, was found to be undetectable at levels of 500 ppb (as total ceftiofur metabolites from incurred residues in milk samples). The selectivity of the assay was 100, because no false-positive results were obtained in tests of >1000 control milk samples. The assay was found to be applicable to the testing of frozen raw milk samples. Results of ruggedness experiments established the operating parameter tolerances for the BetaStar US assay. Results of cross-reactivity testing established that the assay detects certain other beta-lactam drugs (dicloxacillin and ticarcillin), but it does not cross-react with any of 30 drugs belonging to other classes. Abnormally high bacterial or somatic cell counts in rawmilk produced no interference with the ability of the test to detect beta-lactams at tolerance/safe levels.

Comparison of Rapid Tests Used to Detect Antibiotic Residues in Milk1

1990 ◽  
Vol 53 (2) ◽  
pp. 158-164 ◽  
Author(s):  
GARY F. SENYK ◽  
JOSEPH H. DAVIDSON ◽  
JANICE M. BROWN ◽  
ERIC R. HALLSTEAD ◽  
JOHN W. SHERBON
Keyword(s):  
Bacillus Stearothermophilus ◽  
Raw Milk ◽  
Penicillin G ◽  
Beta Lactam ◽  
Rapid Methods ◽  
Milk Samples ◽  
Beta Lactam Antibiotics ◽  
Rapid Tests ◽  
Combined Data ◽  
Disc Assay

Five rapid methods for detection of antibiotics in milk were compared. The Bacillus stearothermophilus var. calidolactis disc assay was also performed on the same samples. The rapid methods were: Angenics Spot Test, Charm II, Delvotest P, Penzyme Farm, and Penzyme Lab III. Ten antibiotics (penicillin G, cephapirin, cloxacillin, ampicillin, streptomycin, chloramphenicol, erythromycin, novobiocin, tetracycline, and gentamicin) were used individually to spike eight raw milk samples at five levels of antibiotic. Antibiotic levels were chosen that would result in zones of <16 mm, 16 mm, and >16 mm on the disc assay. Only the disc assay, Charm II and Delvotest P were compared on non-beta-lactam antibiotics. A small percentage of milks with no antibiotic added tested positive with the Charm II and Penzyme Lab III. On combined data for penicillin G, cephapirin, and cloxacillin, for which all methods were compared, the percent correctly categorized as pass (below actionable) for the <16 mm zone spiked level, reject or caution at the 16 mm zone level, and reject or caution at the >16 mm zone level were: Angenics 79, 83, 100; Charm II 66, 92, 100; Delvotest P 74, 93, 100; Disc Assay 100, 74, 100; Penzyme Farm 93, 61, 92; Penzyme Lab III 81,78, 100 respectively. In most cases, the rapid methods showed greater apparent sensitivity than the disc assay and did not fail to reject milks spiked with antibiotic in excess of the 16 mm zone level.

scholarly journals In vitro evaluation of BO-3482, a novel dithiocarbamate carbapenem with activity against methicillin-resistant staphylococci.

1997 ◽  
Vol 41 (10) ◽  
pp. 2282-2285 ◽  
Author(s):  
Y Adachi ◽  
K Nakamura ◽  
Y Kato ◽  
N Hazumi ◽  
T Hashizume ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clostridium Difficile ◽  
Proteus Mirabilis ◽  
Gram Negative Bacteria ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics

BO-3482, a dithiocarbamate carbapenem, inhibited clinical isolates of methicillin-resistant staphylococci (MRS) at 6.25 microg/ml (MIC at which 90% of isolates tested are inhibited [MIC90]), while the MIC90 of imipenem was > 100 microg/ml. BO-3482 was generally less active than imipenem against methicillin-susceptible Staphylococcus aureus, streptococci, enterococci, and gram-negative bacteria, although BO-3482 showed better activity (MIC90) than imipenem against Enterococcus faecium, Haemophilus influenzae, Proteus mirabilis, and Clostridium difficile. The affinities (50% inhibitory concentrations) of BO-3482 for penicillin-binding protein (PBP) PBP 2' of MRS and PBP 5 of E. faecium (both PBPs have low affinities for ordinary beta-lactam antibiotics) were 3.8 and 20 microg/ml, respectively, reflecting the greater activity of BO-3482 against MRS than against E. faecium.

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