scholarly journals Therapeutic efficacy of Chymotrypsin in acute bovine mastitis

2016 ◽  
pp. 5416-5425
Author(s):  
Marco Leal G
Keyword(s):  
Therapeutic Efficacy ◽  
Somatic Cell Count ◽  
Bovine Mastitis ◽  
Clinical Signs ◽  
Mammary Glands ◽  
The Other ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Lactam Antibiotic ◽  
Acute Mastitis

Objetivo. Evaluar la eficacia terapéutica del fármaco proteolítico “quimotripsina”, en tratamientos conjuntos con un antibiótico betalactámico en vacas con mastitis aguda. Material y métodos. Se evaluaron el conteo de células somáticas (CCS) y los hallazgos semiológicos, comparando la eficacia con un grupo de animales en donde sólo fue utilizado el antibiótico. Resultados. Los resultados revelaron eficacia clínica (disminución del CCS, p<0.01) y ausencia de signos clínicos agudos en el 84.7% de los cuartos observados, incluso observándose respuesta anti-inflamatoria desde las primeras horas del tratamiento. El restante 15.3% también presentó eficacia clínica a la terapia aunque la respuesta fue moderada en comparación con el 84.7% de los casos que tuvieron la respuesta acelerada. Conclusiones. Lo anterior permite concluir que el uso de quimotripsina en casos de mastitis aguda, acelera la respuesta en la glándula mamaria infectada e inflamada, con mayor eficacia que los tratamientos con sólo amoxicilina + ácido clavulánico.Objective. To evaluate the therapeutic efficacy of a proteolytic drug “chymotrypsin” combined with beta-lactam antibiotics in cows with acute mastitis. Material and Methods. Fourteen cows with acute mastitis. Three cows were treated with a beta-latam antibiotic (BLA) and the other eleven cows were treated with chymotrypsin plus beta-lactam antibiotic (C+BLA). The response was evaluated according to the semiological findings, somatic cell count (SCC) and a microbiological culture. Results. There was a therapeutic efficacy comparing the pre and post treatment period (SCC reduction, p<0.01) and a reduction of clinical signs in 84.7% of treated quarters in the first day of treatment (C+BLA) compared with (BLA). Conclusions. Chymotrypsin improves the treatment of acute mastitis when is combined with BLA, controlling the infected mammary glands, compared with the group treated only with amoxicilina and clavulanic acid.

scholarly journals Interaction between non-classical β-lactam compounds and the Zn2+-containing G and serine R61 and R39 d-alanyl-d-alanine peptidases

1981 ◽  
Vol 199 (1) ◽  
pp. 129-136 ◽  
Author(s):  
J A Kelly ◽  
J M Frère ◽  
D Klein ◽  
J M Ghuysen
Keyword(s):  
Degradation Products ◽  
The Other ◽  
Reversible Inhibitor ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Streptomyces Albus ◽  
Penicillanic Acid

Streptomyces albus G secretes a Zn2+-containing D-alanyl-D-alanine peptidase. Streptomyces R61 and Actinomadura R39 secrete D-alanyl-D-alanine-cleaving serine peptidases. The effect of non-classical beta-lactam antibiotics on these three model enzymes has been studied. Mecillinam, cefoxitin, quinacillin, quinacillin sulphone, clavulanate and N-formimidoylthienamycin have no effect on the Zn2+-containing enzyme. 6-Amino-penicillanic acid slowly inactivates this enzyme and 7-aminocephalosporanic acid behaves as a reversible inhibitor. Cefoxitin and N-formimidoylthienamycin are potent anti-bacterial agents; they effectively inactivate the serine R39 enzyme and, to a lesser extent, the serine R61 enzyme. All the other beta-lactam compounds tested, including mecillinam, are slow inactivators of these serine enzymes. The intermediates formed between 6-aminopenicillanic acid and the R61 and R39 enzymes are long- and short-lived respectively, whereas those formed between 7-aminocephalosporanic acid and the same R61 and R39 enzymes are short- and long-lived respectively. Breakdown of the short-lived intermediates thus obtained gives rise to several ninhydrin-positive degradation products. The intermediates formed between clavulanate and the serine enzymes are long-lived. With the R39 enzyme, the inactivated complex formed in a first step undergoes subsequent monomolecular rearrangement to give rise to a second species exhibiting a high absorbance at 273 nm.

Morganella morganii: Epidemiology of Bacteremic Disease

1984 ◽  
Vol 5 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Carolyn McDermott ◽  
Joseph M. Mylotte
Keyword(s):  
Veterans Administration ◽  
Common Source ◽  
Surgical Service ◽  
Beta Lactam ◽  
Morganella Morganii ◽  
Beta Lactam Antibiotics ◽  
Nosocomial Bacteremia ◽  
Lactam Antibiotic ◽  
Administration Hospital ◽  
Prospective Monitoring

AbstractA retrospective review of microbiology records revealed 19 documented episodes of M. morganii bacteremia in 18 patients at a Veterans Administration hospital during a 5.5 year period. Thirteen of 19 bacteremias were related to nosocomial infections; 11 of the 13 nosocomial bacteremias occurred in surgical patients. Nine of the 13 patients with nosocomial bacteremia had received recent therapy with a beta-lactam antibiotic. The most common source of bacteremia was a postoperative wound infection (seven episodes). Only one episode was related to a urinary tract infection.Retrospective analysis showed that clusters of cases of M. morganii bacteremia had occurred almost yearly. This finding prompted a six-month period of prospective monitoring of all cultures for M. morganii to identify human reservoirs in our institution. Sixty percent of all cultures growing M. morganii came from urine cultures, 18% came from wound cultures, and the remaining 22% came from a variety of body fluids or tube drainage. Thirty-one percent of patients harboring M. morganii were on the Surgical Service.M. morganii bacteremia most commonly occurs in postoperative patients who receive beta-lactam antibiotics. From the data in this study, M. morganii is an infrequent cause of bacteremia, and its presence in blood cultures may be an indicator of an environment conducive for an outbreak of nosocomial infection.

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 &gt;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.

scholarly journals Analysis of bacterial cell-wall synthesis to combat antibiotic resistance

2014 ◽  
Vol 70 (a1) ◽  
pp. C701-C701
Author(s):  
Dustin King ◽  
Natalie Strynadka
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Bacterial Cell ◽  
Kinetic Properties ◽  
Enzymatic Reactions ◽  
Beta Lactam ◽  
Antimicrobial Drugs ◽  
Beta Lactam Antibiotics ◽  
Major Structural Component ◽  
Lactam Antibiotic

The peptidoglycan biosynthetic pathway is one of the most important processes in the bacterial cell to be exploited as a target for the design of antimicrobial drugs to combat infection and pathogenesis. This pathway, unique to bacteria, utilizes over twenty enzymes, likely in concert, with reactions that proceed from the cytoplasm, across the membrane and into the periplasmic space culminating in the production of the mesh-like structure composed of polymerized glycan and cross-linked peptide components that form the major structural component of the essential bacterial protective barrier known as the cell wall. Work in our group has aimed at understanding the structural and kinetic properties of several of these enzymes including the glycosyltransferase/transpeptidase activity of a family of enzymes known historically as the penicillin binding proteins (PBPs). As the name implies, these enzymes are also the target of beta-lactam antibiotics, and molecular modifications to transpeptidase variants have been shown to be linked to increased antibiotic resistance in superbugs such as Methicillin Resistant Staphlococcal aureus (MRSA). In parallel, highly disseminated plasmid-encoded beta-lactamase enzymes, with structural and mechanistic ties to the transpeptidases, have also arisen in many of the clinically important bacterial pathogens, leading to further widespread beta-lactam antibiotic resistance. The molecular details of these critical enzymatic reactions in bacterial viability and drug resistance will be presented.

Beta-Lactam Antibiotics Inhibit Agonist-Stimulated Platelet Calcium Influx

1993 ◽  
Vol 69 (05) ◽  
pp. 503-508 ◽  
Author(s):  
Susan F Burroughs ◽  
Gerhard J Johnson
Keyword(s):  
Calcium Influx ◽  
Beta Lactam ◽  
Fura 2 ◽  
Beta Lactam Antibiotics ◽  
Intracellular Release ◽  
Receptor Inhibition ◽  
Lactam Antibiotic ◽  
In Vivo Treatment

Summary(β-lactam antibiotics cause platelet dysfunction with reversible agonist-receptor inhibition, irreversible [14C]-penicillin binding, and inhibition of agonist-stimulated elevation in cytosolic Ca2+ ([Ca2+]i), occurring after 24 h exposure in vitro and after in vivo treatment. We investigated β-lactam antibiotic-induced inhibition of rises in [Ca2+]i stimulated by thrombin, sodium arachidonate or A23187 to determine whether Ca2+ influx or intracellular release was primarily affected. The mean rise in [Ca2+]i, measured with fura-2-AM, was inhibited 43.7-84.1% by penicillin when the extracellular Ca2+ concentration ([Ca2+]e) was 1 mM, but was significantly less inhibited when [Ca2+]e was <1 μM. NiCl2 (2 mM), that blocks Ca2+ influx, caused inhibition comparable to penicillin. MnCl2 (1 mM), that quenches the intracellular fura-2 signal, significantly decreased the rise in 1 mM [Ca2+]i when [Ca2+]e was 1 mM, but did not increase the inhibition caused by penicillin. Penicillin did not inhibit the rise in [Ca2+]i stimulated by inositol-1,4,5-trisphosphate or GTPγS. Therefore, β-lactam antibiotics inhibit agonist-induced elevations of [Ca2+]i primarily through inhibition of Ca2+ influx, which probably accounts for the irreversible inhibition of platelet function seen after prolonged in vitro or in vivo treatment.

scholarly journals Commensal Streptococci Serve as a Reservoir for β-Lactam Resistance Genes in Streptococcus pneumoniae

2015 ◽  
Vol 59 (6) ◽  
pp. 3529-3540 ◽  
Author(s):  
Anders Jensen ◽  
Oskar Valdórsson ◽  
Niels Frimodt-Møller ◽  
Susan Hollingshead ◽  
Mogens Kilian
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Donor Strain ◽  
Beta Lactam ◽  
Content Type ◽  
Beta Lactam Antibiotics ◽  
Lactam Antibiotic ◽  
Ear Infections ◽  
Amino Acid Levels ◽  
The Many

ABSTRACTStreptococcus pneumoniaeis a leading cause of pneumonia, meningitis, septicemia, and middle ear infections. The incidence ofS. pneumoniaeisolates that are not susceptible to penicillin has risen worldwide and may be above 20% in some countries. Beta-lactam antibiotic resistance in pneumococci is associated with significant sequence polymorphism in penicillin-binding proteins (PBPs). Commensal streptococci, especiallyS. mitisandS. oralis, have been identified as putative donors of mutated gene fragments. However, no studies have compared sequences of the involvedpbpgenes in large collections of commensal streptococci with those ofS. pneumoniae. We therefore investigated the sequence diversity of the transpeptidase region of the threepbpgenes,pbp2x,pbp2b, andpbp1ain 107, 96, and 88 susceptible and nonsusceptible strains of commensal streptococci, respectively, at the nucleotide and amino acid levels to determine to what extent homologous recombination between commensal streptococci andS. pneumoniaeplays a role in the development of beta-lactam resistance inS. pneumoniae. In contrast to pneumococci, extensive sequence variation in the transpeptidase region ofpbp2x,pbp2b, andpbp1awas observed in both susceptible and nonsusceptible strains of commensal streptococci, conceivably reflecting the genetic diversity of the many evolutionary lineages of commensal streptococci combined with the recombination events occurring with intra- and interspecies homologues. Our data support the notion that resistance to beta-lactam antibiotics in pneumococci is due to sequences acquired from commensal Mitis group streptococci, especiallyS. mitis. However, several amino acid alterations previously linked to beta-lactam resistance in pneumococci appear to represent species signatures of the donor strain rather than being causal of resistance.

Capillary Gas Chromatographic Method for Determination of Benzylpenicillin and Other Beta-Lactam Antibiotics in Milk

1990 ◽  
Vol 73 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Ute Meetschen ◽  
Michael Petz
Keyword(s):  
Chromatographic Method ◽  
Fused Silica ◽  
Penicillin G ◽  
Methyl Silicone ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Coefficients Of Variation ◽  
Lactam Antibiotic ◽  
Internal Standardization ◽  
Gas Chromatographic Method

Abstract A capillary gas chromatographic method Is described for determining residues of beta-lactam antibiotic residues In milk, with specificity for benzylpenlclllln (penicillin G), phenoxymethylpenlcillin, methlclllln, oxacillin, cloxaclllln, dlcloxaclllln, and nafclllln. Residues are extracted from milk with acetonitrlle. Samples are cleaned up by partitioning between aqueous and organic phases at different pH values. The penicillin residues are methylated with dlazomethane to render them amenable to determination by gas chromatography on a methyl silicone fused silica column. Samples are introduced by spllt/splltless injection using a programmed temperature vaporization injector and are detected by nitrogenselective thermionic detection, internal standardization Is used for quantitation. The limits of detection for all penicillins are well below 1 /μg/kg. Recoveries of spiked samples at 3 and 10 μg/kg are in the range of 42-85% (coefficients of variation 2-5%) and 41-92% (coefficients of variation 3- 7%), respectively.

scholarly journals Characteristics of quinolone and beta-lactam antibiotic resistance in Salmonella isolated from raw meat in Ho Chi Minh City

2021 ◽  
Vol 4 (2) ◽  
pp. 127-137
Author(s):  
Anh Vu Truong Huynh ◽  
Khue Tu Nguyen Hoang ◽  
Hai Chu Van ◽  
Ha Huynh Yen ◽  
Duc Nguyen Anh ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Sensitivity ◽  
Acid Resistance ◽  
Ho Chi Minh City ◽  
Beta Lactam ◽  
Salmonella Spp ◽  
Raw Meat ◽  
Beta Lactam Antibiotics ◽  
Lactam Antibiotic ◽  
Meat Samples

In this study, a total of 380 raw meat samples (pork, beef, and chicken) were collected&nbsp;randomly from traditional markets in Ho Chi Minh City (Vietnam). Salmonella strains were&nbsp;isolated by cultivation methods according to ISO 6579-1:2017, and subsequently confirmed&nbsp;by PCR method (TCVN 8342:2010). These strains were used to test antibiotic susceptibility&nbsp;in six kinds of antibiotics belonging to two groups of quinolones (nalidixic, ciprofloxacin, and&nbsp;ofloxacin), and &beta;-lactam antibiotics (ampicillin, amoxicillin, cephalexin) together with the&nbsp;detection of their resistant genotypes was estimated by Kirby-Bauer method and multiplex&nbsp;PCR. It was noted that the proportion of Salmonella spp. contaminated samples was 42.37%&nbsp;(161/380). Specifically, Salmonella spp. strains found in 50.00 % (63/126), 49.62% (65/131),&nbsp;and 26.83% (33/123) of pork, chicken, and beef samples, respectively. It was noticed that all&nbsp;isolated strains were resistant to six types of antibiotics. The highest proportion was 22.98% for&nbsp;ampicillin (AM), followed by 10.56% for nalidixic acid (NA). The proportions of amoxicillin/acid clavulanic (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), and ofloxacin (OPX) resistant&nbsp;strains were remarkably low (&lt; 10%). There were 37/161 (22.98%) Salmonella strains carrying&nbsp;TEM genes and 5/161 (3.11%) carrying CTX genes. On the other hand, there was no strain&nbsp;carrying SHV genes. Four quinolone-resistant genes including gyrA, gyrB involved in nalidixic&nbsp;acid resistance, and parC, parE involved in ofloxacin and ciprofloxacin resistance were detected&nbsp;in all Salmonella strains that also carried &beta;-lactamase encoding genes. It is important to note&nbsp;that blaTEM-gyrA/B-parC/E genes were simultaneously found in all tested strains. While the&nbsp;proportion of strains containing blaCTX-gyrA/B-parC/E genes was 40.54%, the proportion&nbsp;of strains carrying blaTEM/CTX-gyrA/B-parC/E genes was 5.41%. The results revealed that&nbsp;raw meat might be contaminated with Salmonella spp. that are highly resistant to &beta;-lactam&nbsp;antibiotics and quinolones. Henceforth, it is necessary to establish monitoring and surveillance&nbsp;programs on Salmonella spp. contamination and their antibiotic sensitivity in Vietnam to protect&nbsp;consumers&rsquo; health. The study also provided direct evidence for Salmonella contamination and&nbsp;antibiotic resistance situation in Ho Chi Minh City.

scholarly journals Multiplication of ampC upon Exposure to a Beta-Lactam Antibiotic Results in a Transferable Transposon in Escherichia coli

2021 ◽  
Vol 22 (17) ◽  
pp. 9230
Author(s):  
Tania S. Darphorn ◽  
Yuanqing Hu ◽  
Belinda B. Koenders-van Sintanneland ◽  
Stanley Brul ◽  
Benno H. ter Kuile
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Variable Regions ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Antimicrobial Resistance Genes ◽  
Lactam Antibiotic ◽  
Lactamase Gene

Plasmids play a crucial role in spreading antimicrobial resistance genes. Plasmids have many ways to incorporate various genes. By inducing amoxicillin resistance in Escherichia coli, followed by horizontal gene transfer experiments and sequencing, we show that the chromosomal beta-lactamase gene ampC is multiplied and results in an 8–13 kb contig. This contig is comparable to a transposon, showing similarities to variable regions found in environmental plasmids, and can be transferred between E. coli cells. As in eight out of nine replicate strains an almost completely identical transposon was isolated, we conclude that this process is under strict control by the cell. The single transposon that differed was shortened at both ends, but otherwise identical. The outcome of this study indicates that as a result of exposure to beta-lactam antibiotics, E. coli can form a transposon containing ampC that can subsequently be integrated into plasmids or genomes. This observation offers an explanation for the large diversity of genes in plasmids found in nature and proposes mechanisms by which the dynamics of plasmids are maintained.

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