Posts filed under ‘Resistencia bacteriana’
Resultados de una intervención de descolonización de Staph aureus en pacientes portadores a los que se indica una prótesis articular
Enf Inf & Microb Clin FEB 2015 V.33 N.02
José M. Barbero Allende a, , Juan Romanyk Cabrera b, Eduardo Montero Ruiz a, Alfonso Vallés Purroy c, Virginia Melgar Molero a, Rosa Agudo López a, Luis Gete García a, Joaquín López Álvarez a
a Servicio de Medicina Interna, Hospital Príncipe de Asturias, Alcalá de Henares, España
b Servicio de Microbiología, Hospital Príncipe de Asturias, Alcalá de Henares, España
c Servicio de Cirugía Ortopédica y Traumatológica, Hospital Príncipe de Asturias, Alcalá de Henares, España
La infección de prótesis articular (IPA) es una complicación con graves repercusiones cuyo principal agente responsable en la mayoría de los casos es Staphylococcus aureus. El propósito del presente estudio es evaluar si la descolonización de los pacientes portadores de S. aureus a los que se indica una prótesis articular consigue una disminución en la incidencia de IPA por S. aureus.
Material y métodos
Estudio de intervención antes-después en el que se comparó la incidencia de IPA en pacientes bajo cirugía de prótesis articular de rodilla o cadera entre enero y diciembre de 2011 a los que se realizó estudio de detección de colonización nasal por S. aureus y erradicación si procedía, con un protocolo de mupirocina intranasal y ducha con clorhexidina, con respecto a una serie histórica de pacientes intervenidos entre enero y diciembre de 2010.
En el período de control se realizaron 393 artroplastias en 391 pacientes. En el período de intervención se implantaron 416 prótesis en 416 pacientes. Se realizó estudio de colonización a 382 pacientes (91,8%), de los que 102 fueron positivos (26,7%) y se trataron según el protocolo. Se produjeron 2 casos de IPA por S. aureus frente a 9 en el año control (0,5% vs 2,3%, odds ratio [OR]: 0,2, intervalo de confianza [IC] del 95%: 0,4 a 2,3, p = 0,04).
En nuestro estudio la aplicación de un protocolo de detección de colonización/ erradicación de S. aureus consiguió un descenso significativo de la incidencia de IPA por S. aureus respecto a un control histórico.
Clin Orthop Relat Res. 2010 Aug; V.468 N.8 P.2052-9.
Mortazavi SM1, Schwartzenberger J, Austin MS, Purtill JJ, Parvizi J.
1Department of Orthopaedic Surgery, Imam University Hospital, Tehran University of Medical Sciences, End of Keshavarz Blvd, Tehran 1419733141, Iran.
Deep infection remains one of the most devastating and costly complications after total knee arthroplasty (TKA). The risk of deep infection after revision TKA is reportedly greater than that for primary TKA; however, we do not know the exact incidence of infection after revision TKA.
We determined the incidence of infection after revision, the type of microorganisms involved and TKA, and the potential risk factors for this infection.
We retrospectively reviewed 475 patients (476 knees) with 499 TKA revisions performed between March 1998 and December 2005. Of the 476 knees, 91 (19%) were revised for infection and 385 (81%) were revised for aseptic failure. Preoperative history, results of physical examinations, laboratory and radiographic results, joint fluid aspiration results along with analysis of intraoperative findings were all considered to make an assessment of septic versus aseptic failure modes. Patients were followed for a minimum of 25 months (mean, 65 months; range, 25-159 months).
Deep infection developed in 44 of the 476 knees (9%). The infection rate was higher in patients undergoing revision for infection than in patients with aseptic revisions: 21% (23 of 91) and 5% (21 of 385), respectively. Revision for infection, higher Charlson index, and diagnosis other than osteoarthritis at the time of primary TKA predicted infection of the revision. The risk of infection for patients undergoing TKA revisions was 10-fold higher than for patients undergoing primary TKA at our institution.
Infection of primary TKA is the most important risk factor for subsequent infection of TKA revisions.
LEVEL OF EVIDENCE:
Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
Enferm Infecc Microbiol Clin. 2011 Mar;29 Suppl 4:16-21.
Pascual A1, Cercenado E, Salavert M, Elías García-Sánchez J, Eiros JM, Liñares J, Fernández C, Vila J.
1Departamento de Microbiología, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain. email@example.com
Infections associated with the use of intravascular catheters cause a substantial morbidity and mortality.
New knowledge in the pathogenesis of catheter related bloodstream infections has led to advances in the prevention and management of these infections.
The purpose of the present chapter is to review the most relevant data published recently on pathogenesis and diagnosis of intravascular catheter-related infections.
It is focus in four different aspects:
a) pathogenesis of catheter-related infections and particularly factors affecting biofilm formation and modulation;
b) pathogenesis of intravascular catheter-related infections caused by Staphylococcus lugdunensis; c) news on microbiological diagnosis of catheter-related bacteremia; and
d) evaluation of current use of blood cultures in the era of continuous monitoring blood cultures systems.
Prevalence of Community-Acquired Methicillin-Resistant Staphylococcus aureus Nasal Colonization Among Children.
J Clin Diagn Res. 2014 Dec;8(12):DC12-5.
Shetty V1, Trumbull K2, Hegde A3, Shenoy V4, Prabhu R5, K S6, Palavecino E7, Shetty AK8.
1Associate Professor, Department of Microbiology, K.S. Hegde Medical Academy, Nitte University , Karnataka, India .
2Medical Student, Wake Forest School of Medicine , Winston-Salem, NC .
3Head of Department, Department of Pedodontics, K.S. Hegde Medical Academy, Nitte University , Karnataka, India .
4Head of Department, Department of Pediatrics, K.S. Hegde Medical Academy , Nitte University, Karnataka, India .
5Associate Professor, Department of Pediatrics, K.S. Hegde Medical Academy, Nitte University , Karnataka, India .
6Lecturer, Department of Statistics, K.S. Hegde Medical Academy, Nitte University , Karnataka, India .
7Director Clinical Microbiology, Department of Pathology, Wake Forest School of Medicine , Winston-Salem, NC .
8Professor, Department of Pediatrics, Wake Forest School of Medicine , Winston-Salem, NC .
Invasive infections from community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasingly being encountered in healthy children. Nasal colonization of MRSA is associated with increased risk for acquiring invasive disease. The objective of this study was to determine prevalence and risk factors for CA-MRSA nasal colonization among a healthy paediatric population and to determine antibiotic susceptibilities of S. aureus isolates.
MATERIALS AND METHODS:
Using a cross-sectional study design, children aged 1mnth-17y attending well-child clinic at an academic hospital and a local public school in Mangalore, India were screened for S. aureus colonization via nasal swabs. A questionnaire was administered and data on risk factors for nasal colonization was collected. Samples were obtained from the anterior nares and cultured quantitatively. S. aureus isolates were confirmed by growth on selective media and coagulase testing. Disk diffusion antibiotic susceptibility tests were performed according to Clinical and Laboratory Standard Institute guidelines.
Of the 500 children included in the study, S. aureus was isolated from the anterior nares in 126 (25%) children; four (3%) isolates were classified as CA-MRSA. Factors associated with S. aureus nasal colonization were children <6 y old (p=0.030) and members of joint families (p=0.044). Resistance to many classes of antibiotics were noted among S. aureus isolates including trimethoprim-sulfamethoxazole (39%), ciprofloxacin (16%), erythromycin (19%) and clindamycin (5%). Inducible clindamycin resistance (positive D test) was detected in 11 of the erythromycin-resistant strains not already classified as resistant to clindamycin. No resistance to vancomycin was observed.
Children in India have a high rate of nasal colonization of S. aureus. Nasal colonization of community-associated methicillin-resistant S. aureus exists but is still low among healthy children. The high rate of resistance to many classes of antibiotics among S. aureus strains is of great concern warranting continued surveillance and antimicrobial stewardship.
A longitudinal assessment of antimicrobial susceptibility among important pathogens collected as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) in France between 2004 and 2012.
Antimicrob Resist Infect Control. 2014 Dec 1;3(1):36.
Cattoir V1, Dowzicky MJ2.
1CHU de Caen, Microbiologie & Centre National de Référence de la Résistance aux Antibiotiques (laboratoire associé Entérocoques et résistances particulières des bactéries à Gram positif), Caen, France ; CHU de Caen, Service de Microbiologie – Niveau 3, Avenue de la Côte de Nacre-CS30001, 14033 Caen, Cedex 9, France.
2Pfizer Inc, Collegeville, PA USA.
Clinically important Gram-positive and -negative isolates were collected from patients in France between 2004 and 2012 as a part of the Tigecycline Evaluation and Surveillance Trial.
MICs were determined using methodology described by the Clinical and Laboratory Standards Institute.
In total, 17,135 isolates were contributed by 29 medical centres; respiratory (25.1%) and cardiovascular (20.3%) sources predominated. High susceptibility was observed among Enterococcus spp. and Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]) to linezolid (100%), tigecycline (≥99.8%) and vancomycin (≥94.6%). The percentage of MRSA decreased from 34.3% in 2004 to 20.0% in 2009 before increasing to 34.7% in 2012. Vancomycin, linezolid, levofloxacin and carbapenems were highly active (≥99.6%) against Streptococcus pneumoniae; 3.2% were PRSP. Escherichia coli showed peak susceptibility to the carbapenems (≥99.9%), tigecycline (99.3%) and amikacin (97.9%); significant (p < 0.01) decreases in susceptibility were observed for ampicillin, cefepime and ceftriaxone between 2004 and 2012. ESBL production among E. coli increased from 3.0% (2004) to 14.9% (2012). High susceptibility was noted among Haemophilus influenzae to levofloxacin (100%), amoxicillin-clavulanate (99.2%), carbapenems (≥98.7%) and ceftriaxone (98.5%); β-lactamase production fluctuated with no notable trend between 18.1% (2007) and 27.7% (2011). Klebsiella spp. were highly susceptible to carbapenems (≥99.6%) and amikacin (≥96.4%); significant (p < 0.01) decreases in amoxicillin-clavulanate, cefepime, ceftriaxone, levofloxacin, piperacillin-tazobactam and tigecycline susceptibility were observed among K. pneumoniae between 2004 and 2012. Only imipenem was highly active (96.5% susceptible) against Acinetobacter baumannii. Imipenem and amikacin (87.7% and 87.1% susceptible) were the most active agents against P. aeruginosa; 10.2% of isolates were categorized as multidrug resistant.
Carbapenems, linezolid, tigecycline and vancomycin conserved good in vitro activity against most pathogens (according to their spectrum of activity) in France between 2004 and 2012.
Combinations of β-Lactam or Aminoglycoside Antibiotics with Plectasin Are Synergistic against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus.
PLoS One. 2015 Feb 18;10(2):e0117664.
Hu Y1, Liu A2, Vaudrey J1, Vaiciunaite B1, Moigboi C3, McTavish SM3, Kearns A3, Coates A1.
1Institute for Infection and Immunity, St George’s, University of London, London, United Kingdom.
2University of Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom.
3Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, Colindale, London, United Kingdom.
Bacterial infections remain the leading killer worldwide which is worsened by the continuous emergence of antibiotic resistance. In particular, methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and the latter can be difficult to treat.
The traditional strategy of novel therapeutic drug development inevitably leads to emergence of resistant strains, rendering the new drugs ineffective. Therefore, rejuvenating the therapeutic potentials of existing antibiotics offers an attractive novel strategy.
Plectasin, a defensin antimicrobial peptide, potentiates the activities of other antibiotics such as β-lactams, aminoglycosides and glycopeptides against MSSA and MRSA.
We performed in vitro and in vivo investigations to test against genetically diverse clinical isolates of MSSA (n = 101) and MRSA (n = 115). Minimum inhibitory concentrations (MIC) were determined by the broth microdilution method.
The effects of combining plectasin with β-lactams, aminoglycosides and glycopeptides were examined using the chequerboard method and time kill curves. A murine neutropenic thigh model and a murine peritoneal infection model were used to test the effect of combination in vivo. Determined by factional inhibitory concentration index (FICI), plectasin in combination with aminoglycosides (gentamicin, neomycin or amikacin) displayed synergistic effects in 76-78% of MSSA and MRSA.
A similar synergistic response was observed when plectasin was combined with β-lactams (penicillin, amoxicillin or flucloxacillin) in 87-89% of MSSA and MRSA. Interestingly, no such interaction was observed when plectasin was paired with vancomycin.
Time kill analysis also demonstrated significant synergistic activities when plectasin was combined with amoxicillin, gentamicin or neomycin. In the murine models, plectasin at doses as low as 8 mg/kg augmented the activities of amoxicillin and gentamicin in successful treatment of MSSA and MRSA infections.
We demonstrated that plectasin strongly rejuvenates the therapeutic potencies of existing antibiotics in vitro and in vivo. This is a novel strategy that can have major clinical implications in our fight against bacterial infections.
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Sonication technique improves microbiological diagnosis in patients treated with antibiotics before surgery for prosthetic joint infections.
New Microbiol. 2014 Jul;37(3):321-8.
Scorzolini L1, Lichtner M, Iannetta M, Mengoni F, Russo G, Panni AS, Vasso M, Bove M, Villani C, Mastroianni CM, Vullo V.
1Department of Public Health and Infectious Disease, â€œSapienzaâ€? University, Rome, Italy.
New Microbiol. 2014 Oct;37(4):573. Vasto, Michele [corrected to Vasso, Michele].
Microbiological diagnosis is crucial for the appropriate management of implant-associated orthopedic infections (IAOIs).
Sonication of biomaterials for microbiological diagnosis has not yet been introduced in routine clinical practice. Aim of this study was to describe the advantages and feasibility of this procedure in the clinical setting.
We prospectively studied 56 consecutive patients undergoing revision because of IAOI and compared the sensitivity of sonication of explanted orthopedic implants with standard cultures.
Patients were divided into two groups: those with foreign body infection (FBI, 15 patients) and those with prosthetic joint infection (PJI, 41 patients). Clinical, radiological and microbiological features were recorded.
In the PJI group the sensitivity of sonication in detecting bacterial growth was higher than conventional culture (77% vs 34.1% respectively, p<0.002), while no difference was observed in the FBI group (85.7% vs 86% respectively, p>0.05).
Coagulase-negative Staphylococci accounted for 90% of the bacteria detected by sonication.
Moreover, we found that in the PJI group the sensitivity of sonication was not affected by the timing of antibiotic interruption before surgery.
Sonication remains an important tool to improve microbiological diagnosis in PJIs, especially in patients who received previous antimicrobial treatment.
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