The effects of cephradinum and ceftazidime on the metabolism of Escherichia coli (E. coli) DH5alpha was determined by microcalorimetry. The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37 degrees C. The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (Pm) and the time (tm) corresponding to the maximum power output were calculated. The results show that the ceftazidime has a better inhibitory effect on E. coli DH5alpha than cephradinum.
Anti-Bacterial Agents ; administration & dosage ; pharmacology ; Calorimetry ; methods ; Ceftazidime ; administration & dosage ; pharmacology ; Cephradine ; administration & dosage ; pharmacology ; Escherichia coli ; drug effects ; growth & development ; metabolism ; Microbial Sensitivity Tests

To report on Achromobacter xylosoxidans keratitis in two healthy patients who had worn contact lenses foran extended period of time. A 36-year-old female and a 21-year-old female visited our hospital with ocular pain and blurred vision. Both patients had a history of wearing soft contact lenses for over fve years with occasional overnight wear. At the initial presentation, a slit lamp examination revealed corneal stromal infiltrations and epithelial defects with peripheral neovascularization in both patients. Microbiological examinations were performed from samples of corneal scrapings, contact lenses, contact lens cases, and solution. The culture resulting from the samples taken from the contact lenses, contact lens cases, and solution were all positive for Achromobacter xylosoxidans. Confrming that the direct cause of the keratitis was the contact lenses, the frst patient was prescribed ceftazidime and amikacin drops sensitive to Achromobacter xylosoxidans. The second patient was treated with 0.3% gatifoxacin and fortifed tobramycin drops. After treatment, the corneal epithelial defects were completely healed, and subepithelial corneal opacity was observed. Two cases of Achromobacter xylosoxidans keratitis were reported in healthy young females who wore soft contact lenses. Achromobacter xylosoxidans should be considered a rare but potentially harmful pathogen for lens-induced keratitis in healthy hosts.
Achromobacter denitrificans/*isolation & purification ; Adult ; Amikacin/administration & dosage ; Anti-Bacterial Agents/*administration & dosage ; Ceftazidime/administration & dosage ; Contact Lenses, Extended-Wear/*adverse effects ; Female ; Fluoroquinolones/administration & dosage ; Gram-Negative Bacterial Infections/diagnosis/*drug therapy/*microbiology ; Humans ; Keratitis/diagnosis/*drug therapy/*microbiology ; Tobramycin/administration & dosage

OBJECTIVETo analyze the use of antibiotics and the drug resistance of Pseudomonas aeruginosa in the burn ward of our hospital in the past 11 years, so as to optimize the use of antibiotics in the future.

METHODSBacterial epidemiology during 1991-2001 in our burn ward was investigated. The change of the drug resistance of Pseudomonas aeruginosa was observed by defined daily dose (DDD) of antibiotics in adult patients and by the ranking of antibiotic administration days.

RESULTS(1) Staphylococcus aureus (10.53%-34.40%) and Pseudomonas aeruginosa (75.66%-11.47%) were dominant in our burn ward. (2) Predominant antibiotics used included Penicillin, Amikacin, Vancomycin, Imipenem and Ceftazidime. (3) There was increasing drug resistance of Pseudomonas aeruginosa to the following antibiotics ranking in following order: Piperacillin (41.57%-100.00%), Imipenem (36.36%-98.46%), Ceftazidime (23.46%-97.85%), Amikacin (13.16%-100.00%) and ciprofloxacin (6.90%-100.00%).

CONCLUSIONThere was increasing drug resistance of Pseudomonas aeruginosa to all antibiotics, which might be related to antibiotic abuse.

Amikacin ; therapeutic use ; Anti-Bacterial Agents ; therapeutic use ; Burn Units ; Ceftazidime ; therapeutic use ; Drug Administration Schedule ; Drug Resistance, Bacterial ; drug effects ; Humans ; Imipenem ; therapeutic use ; Penicillins ; therapeutic use ; Pseudomonas aeruginosa ; drug effects ; Vancomycin ; therapeutic use

INTRODUCTIONInstitutional febrile neutropenia (FN) management protocols were changed following the finding of a high prevalence of ceftazidime-resistant Gram-negative bacteraemia (CR-GNB) among haematology patients with FN. Piperacillin/tazobactam replaced ceftazidime as the initial empirical antibiotic of choice, whereas carbapenems were prescribed empirically for patients with recent extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae colonisation/infection. An audit was conducted to determine the impact of these changes.

METHODSData from all FN episodes between October 2008 and December 2010 were collected prospectively, with mid-November 2009 demarking the transition between pre-intervention and intervention periods. Outcomes measured included 30-day mortality post-development of FN and the presence of CR-GNB.

RESULTSThere were 427 FN episodes (200 in the pre-intervention period) from 225 patients. The prevalence of CRGNB was 10.3%, while the 30-day mortality was 4.7%, with no difference between pre-intervention and intervention periods. Independent risk factors for 30-day mortality included the presence of active haematological disease, vancomycin prescription and older age. Independent factors associated with initial CR-GNB were profound neutropenia, the presence of severe sepsis and active haematological disease. Recent ESBL-producing Enterobacteriaceae colonisation/infection was not predictive of subsequent CR-GNB (positive predictive value 17.3%), whereas a model based on independent risk factors had better negative predictive value (95.4%) but similarly poor positive predictive value (21.4%), despite higher sensitivity.

CONCLUSIONA change in the FN protocol did not result in improved outcomes. Nonetheless, the audit highlighted that empirical carbapenem prescription may be unnecessary in FN episodes without evidence of severe sepsis or septic shock, regardless of previous microbiology results.

Academic Medical Centers ; Adult ; Bacteremia ; complications ; drug therapy ; Carbapenems ; therapeutic use ; Ceftazidime ; pharmacology ; Drug Resistance, Multiple ; Febrile Neutropenia ; complications ; drug therapy ; Female ; Gram-Negative Bacteria ; Humans ; Male ; Middle Aged ; Penicillanic Acid ; administration & dosage ; analogs & derivatives ; Piperacillin ; administration & dosage ; Prevalence ; Prospective Studies ; Risk Factors ; Sepsis ; Singapore ; Treatment Outcome ; Universities

BACKGROUND: Acinetobacter baumannii has emerged as a major cause of nosocomial outbreaks. It is particularly associated with nosocomial pneumonia and bloodstream infections in immunocompromised and debilitated patients with serious underlying pathologies. Over the last two decades, a remarkable rise in the rates of multidrug resistance to most antimicrobial agents that are active against A. baumannii has been noted worldwide. We evaluated the rates of antimicrobial resistance and changes in resistance over a 5-year period (2010–2014) in A. baumannii strains isolated from hospitalized patients in a tertiary Greek hospital. MATERIALS AND METHODS: Identification of A. baumannii was performed by standard biochemical methods and the Vitek 2 automated system, which was also used for susceptibility testing against 18 antibiotics: ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanic acid, piperacillin, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, meropenem, gentamicin, amikacin, tobramycin, ciprofloxacin, tetracycline, tigecycline, trimethoprim/sulfamethoxazole, and colistin. Interpretation of susceptibility results was based on the Clinical and Laboratory Standards Institute criteria, except for tigecycline, for which the Food and Drug Administration breakpoints were applied. Multidrug resistance was defined as resistance to ≥3 classes of antimicrobial agents. RESULTS: Overall 914 clinical isolates of A. baumannii were recovered from the intensive care unit (ICU) (n = 493), and medical (n = 252) and surgical (n = 169) wards. Only 4.9% of these isolates were fully susceptible to the antimicrobials tested, while 92.89% of them were multidrug resistant (MDR), i.e., resistant to ≥3 classes of antibiotics. ICU isolates were the most resistant followed by isolates from surgical and medical wards. The most effective antimicrobial agents were, in descending order: colistin, amikacin, trimethoprim/sulfamethoxazole, tigecycline, and tobramycin. Nevertheless, with the exception of colistin, no antibiotic was associated with a susceptibility rate >40% for the entire study period. The most common phenotype showed resistance against ampicillin/sulbactam, cephalosporins, carbapenems, aminoglycosides, ciprofloxacin, and tigecycline. An extremely concerning increase in colistin-resistant isolates (7.9%) was noted in 2014, the most recent study year. CONCLUSION: The vast majority of A. baumannii clinical isolates in our hospital are MDR. The remaining therapeutic options for critically ill patients who suffer from MDR A. baumannii infections are severely limited, with A. baumannii beginning to develop resistance even against colistin. Scrupulous application of infection control practices should be implemented in every hospital unit. Lastly, given the lack of available therapeutic options for MDR A. baumannii infections, well-controlled clinical trials of combinations of existing antibiotics are clearly needed.
Acinetobacter baumannii* ; Acinetobacter* ; Amikacin ; Aminoglycosides ; Anti-Bacterial Agents ; Anti-Infective Agents ; Carbapenems ; Cefotaxime ; Ceftazidime ; Cephalosporins ; Ciprofloxacin ; Colistin ; Critical Illness ; Disease Outbreaks ; Drug Resistance, Multiple ; Gentamicins ; Hospital Units ; Humans ; Imipenem ; Infection Control ; Intensive Care Units ; Pathology ; Phenotype ; Piperacillin ; Pneumonia ; Tetracycline ; Ticarcillin ; Tobramycin ; United States Food and Drug Administration