cefpodoxime-proxetil and Klebsiella-Infections

Raoultella ornithinolytica is a Gram-negative, non-motile, encapsulated, aerobic bacillus belonging to the Enterobacteriaceae family. R. ornithinolytica is a not very common, but emergent causal agent of human infection, and its expression of beta-lactamase provides resistance to commonly used antibiotics. The pathogenetic potential of R. ornithinolytica isolates in human disease has become increasingly important. Several cases of hospital-acquired infection, mostly associated with invasive procedures, or in patients with co-morbidity caused by R. ornithinolytica, have been previously reported in the adult population. In pediatric population, two cases in immunocompromised children, one case in an infant with visceral heterotaxy and one case of catheter-related bacteraemia are described. Here, we present the first case of febrile urinary tract infection due to R. ornithinolytica in an 8-month-old infant, recovered from a previous febrile UTI caused by E. coli and without co-morbidity. The empiric therapy with ceftriaxone, followed by cefpodoxime proxetil, resolved symptoms: the clinical condition of the infant improved rapidly and the treatment eradicated urine from the R. ornithinolytica infection. Since other pathogens rather than R. ornithinolytica are usually identified in children with urinary tract infections, including Escherichia coli, Proteus, Klebsiella and Pseudomonas, the identification of this microorganism in our patient's urine was also unexpected.

Topics: Anti-Bacterial Agents; Cefpodoxime Proxetil; Ceftizoxime; Female; Fever; Humans; Infant; Klebsiella; Klebsiella Infections; Treatment Outcome; Urinary Tract Infections; Vesico-Ureteral Reflux

Cefpodoxime is a semisynthetic third generation cephalosporin analogue with a relatively broader spectrum of antimicrobial activity against gram negative and gram positive organisms. This is attributed to their somewhat increased resistance to degradation by the betalactamase. Cefpodoxime shows good activity against Klebsiella pneumonia, many members of enterobactericeae and almost all strains of Escherichia coli. It is extensively used in human beings against infections caused by susceptible organisms for a prolonged period and even without its judicious indication. Though various researchers have worked on the pharmacokinetic aspects of the drug, its effects on biochemical parameters and spermatozoa activity are scarcely available in literature.. To determine the oral kinetic ( blood and tissue) after single therapeutic dose of cefpodoxime proxetil (20mg/kg oral bid 7 days) in rats of either sex on tissue half life and certain biochemical parameters such as glucose, hemoglobin, protein, ALT, AST and other parameters like tissue residue, sperm count and spermatozoa motility in male rats.. For kinetic studies,24 Wister rats of either sex, 3 months of age, (180-210 gm) were used.(Group I-IV; n=6) Blood samples collected from each animal of Group IV through heart puncture at 0 hour to serve as predrug control. All the group (I-IV) received cefpodoxime proxetil 20 mg/kg once orally as a single dose. At the end of 1,4,12 and 24 hour post oral administration, GroupI,II,III and IVwere utilized for kinetic studies. Blood samples were collected from each animal and vital organs viz brain, lung, liver, spleen, kidney and heart were dissected out for drug analysis and determination of weight. For biochemical parameters, tissue residue and spermatozoa motility, twelve male rats were randomly divided into Groups A and B (n=6) Group B received cefpodoxime (20mg/kg orally bid 7 days) while Group A served as control. Biochemical parameters [Blood glucose, protein, Aspartate transaminase(AST), Alanine transaminase(ALT)and hemoglobin] were measured at 0 and 7 th day while sperm count (total,live and dead)and mean organ weight (study and control group) and tissue residue of drug were evaluated at the end of treatment. Absorption of cefpodoxime was observed at 2 hour and reached a maximum at 4 hour and persisted in blood till 24 hour. Elimination half life in lung was highest followed by heart, liver, kidney and spleen while t½ k in plasma was very low suggesting more affinity of cefpodoxime for tissues than blood.. Blood glucose, protein, AST and ALT activities were not significantly altered but the hemoglobin level and total and live sperm count decreased significantly in the study group compared to the control group. Residual level of cefpodoxime was highest in liver followed by kidney and other study organs. Therefore, the drug should be used in human beings judiciously and further study on human subjects is warranted.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Cefpodoxime Proxetil; Ceftizoxime; Female; Follow-Up Studies; Klebsiella Infections; Klebsiella pneumoniae; Male; Pneumonia, Bacterial; Rats; Rats, Wistar; Sperm Motility; Spermatozoa

Cefpodoxime proxetil (RU 51807) is an enterally absorbed ester prodrug which is rapidly cleaved in vivo after oral administration, with release of the active free acid metabolite cefpodoxime. The in vitro antibacterial activity of the sodium salt of cefpodoxime (RU 51746) against approximately 800 clinical isolates was evaluated comparatively with other orally active beta-lactams. RU 51746 was found to be active against enterobacteria normally susceptible to third generation cephalosporins, with MIC50 values ranging from 0.02 mg/l (Providencia sp) to 5 mg/l (C. freundii). RU 51746 was also active against H. influenzae, including beta-lactamase producing strains (MIC50 0.04 mg/l), oxa-S S. aureus (2,5), beta-hemolytic streptococci (0.05) and S. pneumoniae (0.002). Oxa-R staphylococci and P. aeruginosa were resistant to RU 51746 (MIC50 greater than 40 mg/l for both organisms). The antibacterial activity of RU 51746 was bactericidal in nature and independent from test conditions. The molecule was stable to all the beta-lactamases studied, with the exception of cefuroximase (type Ic). RU 51746 exhibited no strong inhibitory effects on these enzymes, except with Enterobacter P99 (type Ia). A good correlation was found between in vivo activity of RU 51807 and in vitro activity of RU 51746. Cefpodoxime proxetil was found to be more effective than cefaclor in mice with experimental septicemia caused by various streptococci, with a DP50 ratio in the 10-100 range. This advantage was again evidenced for septicemias due to various enterobacteria. In contrast, cefaclor proved more effective in experimental staphylococcus infections. In mice with experimental pneumonia, cefpodoxime proxetil caused sharp falls in K. pneumoniae lung counts. Six days after induction of the infection, 60% of animals under cefpodoxime proxetil had sterile lungs, versus 25% of animals under amoxicillin.

Topics: Animals; beta-Lactamases; Cefpodoxime Proxetil; Ceftizoxime; Dose-Response Relationship, Drug; Enterobacteriaceae; Haemophilus influenzae; Klebsiella Infections; Mice; Pseudomonas aeruginosa; Staphylococcus; Streptococcal Infections

CS-807 is a new oral prodrug of R-3746, a cephalosporin derivative, with potent in vitro and in vivo antibacterial activity against both gram-positive and gram-negative bacteria. The susceptibility of about 1,200 clinical isolates to R-3746 was determined by the agar dilution method. Ninety percent or more of pathogens such as Staphylococcus aureus, streptococci, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, indole-positive and indole-negative Proteus spp., Providencia rettgeri, and Haemophilus influenzae were inhibited at concentrations ranging less than or equal to 0.01 to 1.56 micrograms/ml. Furthermore, at a concentration of 3.13 micrograms/ml, 50% or more of Staphylococcus epidermidis, Morganella morganii, Citrobacter freundii, and Serratia marcescens strains were also inhibited. Pseudomonas aeruginosa and Xanthomonas maltophilia were resistant to R-3746. The activity of R-3746 was scarcely influenced by several growth conditions. R-3746 was highly resistant to hydrolysis by beta-lactamases derived from various species of bacteria. Killing-curve studies demonstrated bactericidal activity of R-3746 at concentrations above the MIC. R-3746 showed high affinity for penicillin-binding proteins 1, 3, and 4 of Staphylococcus aureus and 1A, 1Bs, and 3 of Escherichia coli. Systemic infections in mice caused by various pathogens, including beta-lactamase-producing strains, responded well to therapy with oral doses of CS-807.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Bacterial Proteins; beta-Lactamases; Carrier Proteins; Cefpodoxime; Cefpodoxime Proxetil; Ceftizoxime; Cephalosporins; Chemical Phenomena; Chemistry; Enterobacteriaceae Infections; Escherichia coli Infections; Hexosyltransferases; Klebsiella Infections; Mice; Microbial Sensitivity Tests; Muramoylpentapeptide Carboxypeptidase; Penicillin-Binding Proteins; Peptidyl Transferases; Protein Binding; Proteus Infections; Staphylococcal Infections; Streptococcal Infections