Third-generation cephalosporin resistance in gram-negative bacteria in the community: a growing public health concern

No abstract available.

Third-generation cephalosporin resistance of community-onset Escherichia coli and Klebsiella pneumoniae bacteremia in a secondary hospital

BACKGROUND/AIMS: To enable appropriate antimicrobial treatment for community-onset infections in emergency departments (EDs), data are needed on the resistance profiles of Escherichia coli and Klebsiella pneumoniae, which are the main pathogens of community-onset bacteremia. METHODS: Records were reviewed of 734 patients with E. coli and K. pneumoniae bacteremia who visited the Daegu Fatima Hospital ED, Daegu, Korea between 2003 and 2009. We investigated the demographic data, clinical findings, and antimicrobial susceptibility patterns of the organisms. RESULTS: Of 1,208 cases of community-onset bacteremia, 62.8% were caused by E. coli or K. pneumoniae in an ED of a secondary care hospital. Five hundred and forty-eight cases of E. coli (75%) and 183 cases of K. pneumoniae (25%) were analyzed. Urinary tract infection (43.1%) was most common, followed by intra-abdominal infection (39%) and pneumonia (7.2%). Trimethoprim/sulfamethoxazole, fluoroquinolone, third-generation cephalosporin (3GC) and amikacin resistance rates among E. coli and K. pneumoniae were 22.8%, 19.6%, 6.2%, and 1.3%, respectively. In 2009, the rate of 3GC resistance (10.6%) was significantly higher, compared to the annual averages of 2003 to 2008 (6.1%; p = 0.03). Previous exposure to antibiotics was an independent risk factor for 3GC resistance in multivariate logistic regression analysis. CONCLUSIONS: The rate of 3GC resistance increased in community-onset infections, and previous exposure to antibiotics was an independent risk factor. Despite the increased 3GC resistance in community-onset infections, an amikacin combination therapy could provide an option for treatment of bacteremic patients with previous antibiotic exposure in an ED.

Identification of natural compounds which inhibit biofilm formation in clinical isolates of Klebsiella pneumoniae.

Klebsiella pneumoniae, an important opportunistic pathogen, exists as a biofilm in persistent infections and in-dwelling medical devices. With the objective of identifying natural compounds inhibiting biofilm formation in K. pneumoniae, 35clinical isolates were screened,out of which 7 strong biofilm producers were identified. Six natural compounds were tested for their inhibitory effects on bacterial growth and biofilm formation by determining the minimum inhibitory concentration and minimum concentration for biofilm inhibition (MBIC) for each compound. The results show that reserpine followed by linoleic acid, were the most potent biofilm inhibitors. Reserpine, an efflux pump inhibitor was effective at biofilm inhibition at a concentration of 0.0156 mg/mL, 64-fold lower concentration than its MIC. Linoleic acid, an essential fatty acid was effective as a biofilm inhibitor at 0.0312 mg/mL, which is 32-fold lower than its MIC. Berberine, another plant derived antimicrobial, chitosan and eugenol had an MBIC value of 0.0635 mg/mL. Curcumin, a natural phenolic compound was effective at biofilm inhibition at a concentration of 0.25 mg/mL, which is 50 fold less than its MIC. Notably, the MIC and MBIC data on these 6 natural compounds was reproducible in all seven high biofilm forming isolates of K. pneumoniae. The present report is a comprehensive comparative analysis of the dose dependent inhibition of various natural compounds on biofilm formation in K. pneumoniae.

Actividad bactericida de superficies de cobre frente a bacterias asociadas a infecciones nosocomiales, en un modelo in vitro de adherencia y sobrevivencia / Adherence to copper and stainless steel metal coupons of common nosocomial bacterial strains

Background: Copper has a bactericidal activity against a series of bacterial strains. Aim: To measure resistance to bacterial adherence of copper (Cu) and stainless steel (SS) metal coupons. Material and Methods: Bacterial strains causing nosocomial infections in Chile were analyzed. Bacterial adherence was studied using apreviously described method based on a system of metal coupons that are immersed in culture media containing the bacteria ofinterest at room temperature. Results: Adherence to Cu and SS coupons was differentfor Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae and Acinetobacter baumannii strains. For these strains, no adherence to Cu coupons occurred during the 48 h observation period compared to a rapidly increasing adherence to SS coupons, with a final colony count of 1.00E + 07 cfu/mL. For two different Pseudomonas aeruginosa clinical strains, inhibition of adherence was not observed on Cu coupons, and colony counts were similar for Cu and SS using the standard inoculum (2-3 xlO7 cfu).Apartial decrease in adherence was observed for Cu but not for SS coupons, when a lower inoculum was used. Conclusions: Copper surfaces represent an interesting option to reduce bacterial contamination in the hospital environment due to its resistance to bacterial adhesión ofmost ofthe common nosocomial bacterial strains.

Rinoescleroma en edad escolar: a propósito de un caso / Rinoesclerosis in age school: a purpose of a case

El Rinoescleroma es una infección crónica granulomatosa progresiva causada por un bacilo Gram negativo Klebsiella rhinoescleromatis. Afecta usualmente la cavidad nasal y disemina rápidamente a estructuras vecinas es inespecifica: rinorrea purulenta, obstrucción nasal, epistaxis. El diagnóstico se basa en la demostración del microorganismo causal por biopsia o cultivo. En la biopsia del tejido afectado se aprecian células de MIKULICZ patognomónicas. El tratamiento consiste en la antibióticoterapia adecuada. Describimos un caso histológicamente de mostrado de Rinoescleroma, en un escolar masculino de 11 años de edad. Hacemos énfasis en la importancia de conocer esta patología debido a su poca frecuencia en nuestro medio, además de presentarse atípicamente en un escolar y de sexo masculino, ya que predomina entre la tercera y cuarta década de la vida, en el sexo femenino, y es el primer caso reportado en el Hospital Padre Justo de Rubio. Estado Táchira

Identificacion de las proteinas antigenicas de Klebsiella pneumoniae / Identification of antigenic proteins of klebsiella pneumoniae

La klebsiella pneumoniae es un microorganismo causante de multiples infecciones que cursan con una alta mortalidad. Es uno de los agentes nosocomiales mas frecuentes en Colombia y en otros paises sin que se haya podido controlar adecuadamente, debido a su virulencia y su alta resistencia a los antibioticos. A pesar de que sus componentes antigenicos polisacaridos y lipopolisacaridos han sido ampliamente estudiados, no ocurre asi con los antigenos proteicos. Esta investigacion describe la identificacion de proteinas antigenicas de klebsiella pneumoniae por medio de la PAGE y el inmunoblot. Se utilizaron cepas aisladas en muestras clinicas y sueros de pacientes de cuatro hospitales generales de Bogota. Se demostro la existencia de por lo menos 32 proteinas diferentes de klebsiella pneomoniae con pesos moleculares entre 11 y 210K, de las cuales alrededor de 18 se mostraron ser antigenicas. Se encontraron tres proteinas antigenicas de 167 K, 54 K y 39 K que son reconocidas por el sistema inmune humoral despues de que se ha superado la infeccion y estas podrian tener algun papel inmunogencio protector.