Radiolytic studies of cefozopran hydrochloride in the solid state

Background: The radiation sterilization is one of the best methods for sterilizing vulnerable degradation drugs like cefozopran hydrochloride. Results: Chemical stability of radiosterylized cefozopran hydrochloride, was confirmed by spectrophotometric and chromatographic methods. EPR studies showed that radiation has created some radical defects whose concentration was no more than several dozen ppm. The antibacterial activity of cefozopran hydrochloride irradiated with a dose of 25 kGy was unaltered for Gram-positive bacteria but changed for two Gram-negative strains. The radiation sterilized cefozopran hydrochloride was not in vitro cytotoxic against human CCD39Lu normal lung fibroblast cell line. Conclusions: Cefozopran hydrochloride in solid state is not resistant to radiation sterilization and this method cannot be used for sterilization of this compound.

Identifying Genetic Susceptibility to Sensitization to Cephalosporins in Health Care Workers

Exposure to cephalosporins could cause occupational allergic diseases in health care workers (HCWs). We evaluated the prevalence of serum specific IgE and IgG antibodies to cephalosporin-human serum albumin (HSA) conjugate and to identify potential genetic risk factors associated with sensitization to cephalosporins in exposed HCWs. The study population consisted of 153 HCWs who had been exposed to antibiotics in a single university hospital and 86 unexposed healthy controls. A questionnaire survey of work-related symptoms (WRS) was administered. A skin-prick test (SPT) was performed, and serum-specific IgE and IgG antibodies to 3 commonly prescribed cephalosporins were measured by ELISA. Four single-nucleotide polymorphisms of the candidate genes related to IgE sensitization were genotyped. The prevalence of WRS to cephalosporins was 2.6%. The prevalence rates of serum-specific IgE and IgG antibodies to cephalosporins were 20.3% and 14.7%, respectively. The FcepsilonR1beta-109T > C polymorphism was significantly associated with IgE sensitization to cephalosporins in HCWs (P = 0.036, OR = 3.553; CI, 1.324-9.532). The in vitro functional assay demonstrated that the T allele of FcepsilonR1beta-109T had greater promoter activity than did the C allele (P C polymorphism may be a potential genetic risk factor for increased IgE sensitization to cephalosporins.

AmpC beta lactamases among Gram negative clinical isolates from a tertiary hospital, South India

AmpC â-lactamases are cephalosporinases that hydrolyze cephamycins as well as other extended-spectrum cephalosporins and are poorly inhibited by clavulanic acid. Although reported with increasing frequency, the true rate of occurrence of AmpC â-lactamases in different organisms, including members of Enterobacteriaceae, remains unknown. The present study was designed to determine the occurrence of AmpC enzyme-harbouring Gram-negative clinical isolates in a tertiary care hospital in Pondicherry state, South India. A total of 235 Gram negative clinical isolates were tested for resistance to cefoxitin, third generation cephalosporin (3GC) antibiotics, ampicillin, amikacin, co-trimoxazole, gentamicin, meropenem and tetracycline by disc diffusion method. Isolates found resistant to 3GC and cefoxitin were tested for the production of AmpC â -lactamases by three dimensional extraction method and AmpC disc method. Isolates found to sensitive to 3GC were subjected to disc antagonism test for inducible AmpC production. One hundred and thirty four (57 percent) strains were resistant to 3GC, among which 63(47 percent) were positive for plasmid-mediated AmpC beta lactamases production. Among the 101 strains sensitive to 3GC, 23 (22.7 percent) revealed the presence of inducible AmpC beta lactamases by disc approximation test. A total of 80.9 percent (51/63) of screen positive isolates were detected by Amp C disc test and 93.6 percent (59/63) by three dimensional extraction method. Out of the 86 AmpC producers, 67 (77.9 percent) were cefoxitin resistant .Inducible AmpC was not found in Esch.coli and Klebsiella spp. The AmpC producers also concurrently showed multidrug resistance pattern. AmpC producers were found to be prevalent in our hospital and though three dimensional extraction test detects AmpC better, the disk test is easier to perform routinely and is user- friendly.

Bacteriocins produced by L fermentum and L acidophilus can inhibit cephalosporin resistant E coli

Reemerging infections occur due to resistant bacteria. Such infections create restrictions for clinicians and microbiologists in drug selection. Such problems demand new strategies for solution. Use of bacteriocins for this purpose may be fruitful. In the present research work, the inhibitory effects of bactericins on cephalosporin resistant Escherichia coli are used as model system for the control of antibiotic resistant pathogenic bacteria. Cephalosporin resistant Escherichia coli strain was isolated from pus by using conventional methodology. For bacteriocin production, Lactobacilli strains were selected by using selective media. Out of seventy two strains isolated from yogurt, fecal materials of human, chick, parrot and cat, only two strains (strain 45 and strain 52) were found to produce bacteriocins having antimicrobial potential against cephalosporin resistant Escherichia coli. Biochemical characterization showed that strain 45 belonged to group of Lactobacillus fermentum and strain 52 to Lactobacillus acidophilus. Both strains showed maximum growth at 25ºC and 35ºC respectively. Suitable pH was 5.5 and 6.0 for Lactobacillus fermentum and Lactobacillus acidophilus respectively. Bacteriocins produced by both strains were found stable at 50, 75 and 100ºC for 60min. Function of bacteriocin was also not disturbed due to change in pH. These findings suggest that bacteriocin produced by Lactobacillus fermentum and Lactobacillus acidophilus can be used for the infection control of cephalosporin resistant Escherichia coli.

A comparaçåo das atividades antimicrobianas da cefepima e da ceftazidima em 1015 amostras bacterianas isoladas no Hospital Såo Paulo / Comparasion of the activity of cefepime and ceftazidime tested in 1015 bacterial samples isolated in Hospital Såo Paulo

O presente estudo tem como objetivo comparar a atividade in vitro de uma nova cefalospirina (4ª geraçåo), a cefepima, com a da ceftadizima. Foram testadas, através da técnica de microdiluiçåo em placa, 1015 amostras bacterianas clínicas isoladas no Hospital Såo Paulo/Escola de Medicina no período de junho a julho de 1992. Para as espécies de endobactérias de maneira geral, a concentraçåo de antimicrobianos que inibiu 50 por cento das amostras (MIC 50) variou de <0,12 a u2 g/ml tanto para a cefepima quanto para a ceftazidima. Porém, a porcentagem de amostras de Enterobacter spp. sucetíveis foi superior para a cefepima (74//versus 61 por cento). Contra as amostras de Pseudomonas aeroginosa, a ceftazidima apresentou potência pouco superior àquela demonstrada pela cefepima (MIC50s de ug/ml e 8 ug/ml respectivamente), com porcentagem de sensibilidade também superior (73 por cento versus 59 por cento). Das 569 amostras de bacilos gram-negativos avaliadas, 85 por cento foram suscetíveis à ceftdazidima e 80 por cento à cefepima. Entre os cocos garm-positivos, como os Staphylococcus aureus sensíveis à oxacilina, a cefepima (MIC90 4ug/ml) foi duas a quatro vezes mais ativa que a ceftazidima (MIC90 16ug/ml). Porém, como já era esperado, as amostras de estafilococos resistentes à oxacilina e as amostras de Enterococcus faecalis foram resistentes às duas drogas testadas, com MIC50>16ug/ml. Nesse estudo, a cefepima mostrou atividade e espectro contra gram-negativos semelhantes àquele das cefasporinas de 3ª geraçåo com atividade antipseudomonas (ceftazidima). Além disso, sua atividade contra gram-positivos foi semelhante àquela demosnstrada pelas celafosporinas de 1ª geraçåo. Apesar do avanço conquistado com as cefalosporinas de 4ª geraçåo, o uso extensivo e/ou inapropriado dessas drogas facilitará o aparecimento de cepas resistentes e a pesquisa por substâncias mais ativas deve continuar

Determinación de la enzima B-lactomasa (penicilina B-lactámica Amido hidrolasa E.C.3.5.2.6) en microorganismos gram - negativos aislados en urocultivos / B-lactams enzime determination (penicilin B-lactamic amido hydrolase E.C.3.5.2.6) in gramm negatives microorganism in urocultive isolation

Se han aislado 60 cepas de urocultivos procedentes de pacientes ambulatorios que acuden al Servicio Acádemico Asistencial de Análisis Clinicos S.A.A.A.C., los cuales fueron identificados a traves de pruebas bioquímicas como la familia de Enterobacteroceae E.Coli, Enterobacter SP., proteus SP., citrobacter SP., Kichsiella SP. Se probó la suceptibilidad frente a los antibióticos B-lactámicos, determinándose en antibiograma por el método de difusión en medio sólido yla concentración mínima inhibitoria. La presencia de B-lactomasa fue identificada por los métodos:iodometrico, membrana considerada de Andrade, microbiológico, según SYKES,R.B (39) y PADAC ó cefalosporina cromogénica, segun JORGENSEN, J.H y col (11) en todas las cepas. Los resultados permiten concluir que la C.M.I. de las cepas en estudio frente a los antibióticos fué mayor que la de los respectivos discos de sensibilidad. El método métrico para identificación de B-lactamasa mostró ser el más sensible, fácil y aplicable por los laboratorios de anális clínicos.