PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Acinetobacter Infections”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

Considerations in control and treatment of nosocomial infections due to multidrug-resistant Acinetobacter baumannii.

We sought to control infection due to multidrug-resistant Acinetobacter baumannii (MDR-Ab) by identifying isolates as clonally related, leading to enhanced infection-control measures, including cohorting, surveillance, contact precaution, initial therapy with ampicillin/sulbactam and local polymyxin B, and, more recently, therapy with synergistic antibiotic combinations. Class restriction of cephalosporins has been associated with a reduction in cephalosporins-cephamycin-carbapenem resistance among nosocomial Klebsiella isolates. This has been supplemented by restriction of carbapenem use after an initial 24-h period in an effort to reduce the selection of porin-deficient, carbapenem-resistant A. baumannii and Pseudomonas aeruginosa. Evidence is reviewed suggesting that eradication of MDR-Ab nosocomial colonization may prevent subsequent infection. Relatively few standard antibacterial drugs remain active against MDR-Ab. Published clinical results of therapy with these agents are reviewed, and in vitro evidence of synergy between them is presented that suggests that combination therapy should be studied for enhanced clinical activity.

Acinetobacter Infections↗

Severe nosocomial infections with imipenem-resistant Acinetobacter baumannii treated with ampicillin/sulbactam.

Forty consecutive patients with nosomial infections caused by multidrug-resistant Acinetobacter baumannii were treated with intravenous ampicillin/sulbactam. The infections were primary bloodstream (32.5%), pneumonia (30%), urinary tract (15%), peritonitis (7.5%), surgical site (7.5%), meningitis (5%) and sinusitis (2.5%). Most were severe infections with underlying conditions (median APACHE II score: 14.5) and 72.5% occurred in the ICU. Twenty-seven (67.5%) were improved/cured, seven (17.5%) were failures and six (15%) were considered to have an indeterminate outcome because patients died within the first 48 h of treatment. Two cases of meningitis were treated and did not respond. The median daily dose of ampicillin/sulbactam was 6 g/3 g and six patients received 12 g/6 g. No adverse effects were observed. This study indicates that ampicillin/sulbactam may be a good and safe therapeutic option to treat severe nosocomial infections caused by multi-drug resistant A. baumannii.

Acinetobacter Infections↗

Acinetobacter species as a cause of catheter-related infections.

In recent years, Acinetobacter species have emerged as clinically important pathogens. Though these organisms are widely prevalent in nature, most human infections are hospital-acquired. Acinetobacter baumannii is the predominant species. Nosocomial Acinetobacter baumannii infections such as respiratory tract infections, urinary tract infections, meningitis following neurosurgical procedures, and bacteremia mainly affect patients with severe underlying disease in the ICU and often, in the setting of nosocomial outbreak. The occurrence of multiresistant strains often limits therapeutic options. A substantial part of Acinetobacter baumannii bacteremia cases represent catheter-related infections that usually carry a favorable prognosis. Acinetobacter species other than Acinetobacter baumannii are less frequently reported as a cause of infection in humans. Bacteremia due to these organisms is mostly sporadic and almost exclusively related to intravascular devices. The underlying diseases are often less severe than those of patients affected by Acinetobacter baumannii infections. The clinical course is usually benign and the infection responds readily to catheter removal irrespective of the appropriateness of antimicrobial therapy.

Acinetobacter↗

The persistence and clonal spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital.

This study describes the persistence and spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital. Acinetobacter spp. are reported with increasing frequency as a cause of nosocomial infection. The species most implicated in these infections is Acinetobacter baumannii. Following an outbreak of infection with Acinetobacter 13TU within the intensive therapy unit (ITU) of Edinburgh Royal Infirmary (ERI) during 1994-1995, the current epidemiological Acinetobacter situation within the hospital was monitored to determine whether or not control of infection procedures instigated at that time had been successful in controlling the outbreak. Sixty-eight strains of Acinetobacter spp were isolated from clinical specimens received from various wards in the ERI and other associated hospitals over a 7-month period. Each isolate was typed phenotypically by the API20NE system and genotypically by pulsed field gel electrophoresis (PFGE) in order to compare them with the previous outbreak strain. Fifty-three percent of the isolates collected were originally identified as A. junii by API 20 NE, of which 83% (mainly from ITU) were shown to be genotypically related to the previous outbreak strain. Subsequent tDNA fingerprinting of one of the original outbreak strains showed it to be a member of the genospecies 13TU and not A. junii as originally thought.

Acinetobacter↗

Pathogenic significance of Acinetobacter calcoaceticus: analysis of experimental infection in mice.

The phenomenon that mixed infection with certain species of bacteria and Acinetobacter calcoaceticus is more virulent than single infection was analyzed experimentally. In mixed infections with A. calcoaceticus paired with either Escherichia coli, Serratia marcescens, or Pseudomonas aeruginosa, the virulence of the latter three organisms was markedly increased over that of single infections only by slime-producing strains of A. calcoaceticus. Of the 100 strains of A. calcoaceticus tested, 14 had slime-producing ability. There was scarcely any difference in the chemical components of the slimes of the two strains tested, but the components of the slime of P. aeruginosa were different from those of these strains. The slime of these two strains exhibited lethal activity in mice, but no correlation was found between the amount of slime produced and the virulence. The slime enhanced the virulence of E. coli, S. marcescens, and P. aeruginosa when it was inoculated along with their viable cells. Furthermore, the slime exhibited potent cell-impairing activity against mouse neutrophils both in vitro and in vivo. This activity was considered to be mainly responsible for the enhancement of virulence in mixed infections.

Acinetobacter↗

Epidemiology and infection control implications of Acinetobacter spp. in Hong Kong.

In a previous study, we showed that Acinetobacter genomic DNA group 3 was the most common species among blood culture isolates and was commonly found on superficial carriage sites of the healthy and the sick, which are different findings from those reported in Europe and North America. We used amplified ribosomal DNA restriction analysis and pulsed-field gel electrophoresis to study further the molecular epidemiology of acinetobacters in our region. Over a study period of 6 weeks with 136 consecutive routine clinical isolates (1.33% of all specimens), genomic DNA groups 2 (Acinetobacter baumannii), 3, and 13TU were obtained from 59 of 69 positive patients. There is a significant difference in the specimen sources of the three genomic DNA groups, with group 13TU being significantly associated with the respiratory tract (chi-square exact test, P = 0.0064). Settle plates showed a significantly heavier environmental load from the intensive care unit (ICU) than from the four surgical wards examined (22 of 70 versus 76 of 120 plates with <5 colonies; chi-square test, P < 0. 0001). Genomic group 3 accounted for 6 of 12 clusters of possibly related strains among patients, between patients and the ICU environment, and in the ICU environment. Genomic groups 2 and 3 accounted for 21% of the 132 genomically identified isolates recovered from 21 of 41 local vegetables, 53 of 74 fish and meat samples, and 22 of 60 soil samples. Group 13TU was present only in patients' immediate surroundings. The role played by the environment and by human carriage should be evaluated in order to devise a cost-effective infection control program pertinent to our situation of acinetobacter endemicity.

Acinetobacter↗

DNA microarray-based detection of nosocomial pathogenic Pseudomonas aeruginosa and Acinetobacter baumannii.

Infection by nosocomial pathogenic bacteria is increasingly becoming a major threat to the patients in the hospital. We have developed a diagnostic DNA microarray for the detection of two important nosocomial pathogens, Pseudomonas aeruginosa and Acinetobacter baumannii. The diagnostic DNA microarray contains the species-specific probes of 15mer oligonucleotides designed based on the sequences of 23S ribosomal DNA. The performance of DNA microarray in diagnosing P. aeruginosa and A. baumannii was evaluated using reference bacteria as well as clinical specimens such as blood, stool, pus, sputum, urine and cerebrospinal fluid. Using this DNA microarray, A. baumannii could be successfully detected in 11 out of 13 clinical specimens, thus giving the sensitivity of 84.6% with the specificity of 100% and the positive predictive value of 100%. P. aeruginosa could also be detected in 25 out of 26 clinical specimens, showing the sensitivity of 96.2%, the specificity of 100%, and the positive predictive value of 100%. These results suggest that two nosocomial pathogens, P. aeruginosa and A. baumannii, can be efficiently diagnosed by using the DNA microarray developed in this study.

Acinetobacter baumannii↗

[Etiological importance and identification of Acinetobacter in secondary and endogenous infections].

A total of 2 museum and 63 clinical Acinetobacter strains were studied. In these studies, carried out with the use of Oxi/Ferm Tube and API 20E, 56 cultures were classified as V. anitratus and 9, as V. lvoffii. To screen Acinetobacter in routine studies, simple tests were proposed: staining by Gram's method, the study of morphology and motility, the determination of the character of growth in Endo's medium and Russel's medium, the cytochromoxidase test. The occurrence of Acinetobacter in pathological material was found to vary between 0.43% and 3.5%, depending on the localization of the process.

Acinetobacter↗

Infective endocarditis of an interventricular patch caused by Acinetobacter haemolyticus.

A case of infective endocarditis caused by Acinetobacter haemolyticus affecting and interventricular patch is reported. The patient, a 21-year-old man with a Fallot's tetralogy who had undergone cardiovascular surgery several years before, received imipenem and gentamicin for 6 and 4 weeks respectively and showed a good response without needing surgical treatment. Endocarditis by Acinetobacter species is very unusual and, to our knowledge, this is the first reported case of infective endocarditis caused by A. haemolyticus. As the clinical characteristics and the response to antibiotics appear to be similar to those reported for infective endocarditis by Acinetobacter lwoffi, prosthetic infective endocarditis by A. haemolyticus is apparently not always an indication for surgical treatment.

Acinetobacter↗

Relevance of digestive tract colonization in the epidemiology of nosocomial infections due to multiresistant Acinetobacter baumannii.

Fecal colonization with multiresistant Acinetobacter baumannii was evaluated in 189 consecutive patients in intensive care units (ICUs) during two different 2-month periods (October-November 1993 and May-June 1994). Rectal swabs were obtained weekly from admission to discharge from the ICU. Overall, 77 patients (41%) had multiresistant A. baumannii fecal colonization; colonization was detected in 55 (71%) of the patients within the first week of their ICU stay. Clinical infections due to multiresistant A. baumannii occurred more frequently in patients with fecal colonization than in those without fecal colonization (26% vs. 5%, respectively; P < .001). The reinforcement of isolation measures between study periods reduced both the number of fecal carriers of multiresistant A. baumannii (from 52% to 31%; P < .01) and the number of patients with multiresistant A. baumannii infections (from 17% to 11%; no statistical significance). The digestive tract of ICU patients could be an important epidemiologic reservoir for multiresistant A. baumannii infections in hospital outbreaks. Further prospective studies should be undertaken to define the relative significance of digestive tract colonization compared with other body site colonizations.

Acinetobacter↗

Colistin offers prolonged survival in experimental infection by multidrug-resistant Acinetobacter baumannii: the significance of co-administration of rifampicin.

The effect of colistin on bacterial eradication and survival was tested in experimental infection by multidrug-resistant Acinetobacter baumannii. The thigh infection model was applied in 86 neutropenic Wistar rats. Six rats were used for the induction of neutropenia and for the selection of the dose regimen of colistin; the remainder was equally divided into four groups: A, controls; B, rifampicin; C, colistin; and D, both agents. Therapy was administered 5 h after bacterial challenge; 5mg/kg of rifampicin was administered intravenously and 3mg/kg of colistin intramuscularly. Survival was recorded in 10 animals of each group. The remaining 10 rats per group were killed 4h after therapy; blood and tissue samples were sampled. Median survival of animals of groups A, B, C and D was 2.00, 2.50, 4.00 and 4.00 days, respectively (P=0.0048 between A and C and P=0.0012 between A and D. Mortality rates after 6 days of follow-up were 100, 100, 100 and 70%, respectively (P=0.018 between groups). Statistically significant decreases of bacteria were found in blood, liver, lung and spleen of group B compared with A; in lung of group C compared with A; and in blood and liver of group D compared with A. Colistin was effective in prolonging survival in an experimental thigh infection by multidrug-resistant A. baumannii in neutropenic rats. Its activity was enhanced after co-administration with rifampicin. These results mandate the application of colistin in the event of infections by multidrug-resistant pathogens and the need for its co-administration with rifampicin.

Acinetobacter Infections↗

[Presence of various Acinetobacter species in urinary tract infections].

Species classification of 39 strains of Acinetobacter isolated from urinary tract infections (UTI) was performed by API 20NE tests. On the whole 24 biotypes were differentiated which formed 4 species and one biotype had no defined species classification. Acinetobacter baumani was most numerously represented. Seventy seven percent of strains were isolated from urine samples from women. About 90% of Acinetobacter strains were isolated as single pathogens. Sensitivity of these strains to 23 antibiotics and chemotherapeutics using ATB-UR and disc diffusion technique was evaluated. Of all cephalosporins tested ceftazidime was the most active. All strains tested were sensitive to imepenem. The high percentage of strains was sensitive to quinolones of IIIrd generation. The high percentage of strains was resistant to nitrofurantoin.

Acinetobacter↗

The emergence of resistant strains of Acinetobacter baumannii: clinical and infection control implications.

A prospective study was undertaken to determine colonization rates, susceptibility profiles, and outcomes in patients with clinical isolates of Acinetobacter baumannii. Fifty percent of patients became colonized with A. baumannii, and 29% of these patients had clinical and colonizing isolates with discordant susceptibility profiles, without apparent relation to antibiotic use. Barrier infection control measures are necessary to prevent nosocomial transmission.

Acinetobacter↗

Comparison of a repetitive extragenic palindromic sequence-based PCR method and clinical and microbiological methods for determining strain sources in cases of nosocomial Acinetobacter baumannii bacteremia.

Using a repetitive extragenic palindromic PCR (REP-PCR), we genotypically characterized strains causing nosocomial Acinetobacter baumannii infections and analyzed the source of bacteremia in 67 patients from an institution in which infections by this bacterium were endemic. Six different genotypes were found, including 21, 27, 3, 9, 3, and 4 strains. The probable source of bacteremia, according to clinical and/or microbiological criteria, was known in 42 patients (63%): respiratory tract (n = 19), surgical sites (n = 12), intravascular catheters (n = 5), burns (n = 3), and urinary tract (n = 3). The definite source of bacteremia, according to REP-PCR, could be established in 30 (71%) out of the 42 patients with strains from blood and other sites; in these cases clinical and microbiological criteria for the source of bacteremia were thus confirmed. In the remaining 12 patients (29%) the probable source was refuted by the REP-PCR method. The definite sources of bacteremia according to genotype were as follows: respiratory tract in 13 patients (31%), surgical sites in 8 (19%), intravascular catheters in 4 (9%), burns in 3 (7%), and urinary tract in 2 (5%). A comparison of strains from blood cultures and other sites with regard to their REP-PCR and antimicrobial resistance profiles was also made. Taking the REP-PCR as the "gold standard," the positive predictive value of antibiotype was 77% and the negative predictive value was 42%. In summary, the utility of the diagnosis of the source of nosocomial A. baumannii bacteremia using clinical and/or microbiological criteria, including antibiotyping, is limited, as demonstrated by REP-PCR.

Acinetobacter Infections↗

Retrospective analysis of multidrug-resistant Acinetobacter baumannii strains isolated during a 4-year period in a university hospital.

OBJECTIVE: To describe the epidemiology of Acinetobacter baumannii infection during 2000-2003 and to determine whether the multidrug-resistant strains were already present in our Toulouse hospital before the 2003 French national outbreak. DESIGN: Descriptive molecular and clinical epidemiologic study of A. baumannii isolates using a combination of antibiotyping and pulsed-field gel electrophoresis (PFGE). SETTING: A 1,000-bed university hospital in Toulouse, France. METHODS: All clinical samples that had tested positive for A. baumannii between January 1, 2000, and December 31, 2003, were collected. Multidrug-resistant isolates of A. baumannii were then submitted to PFGE, and clinical characteristics of the source patients were noted. RESULTS: A total of 1,277 A. baumannii samples were identified, 791 of which had not been previously identified; 148 were positive for multidrug-resistant strains. These strains were more likely to have been isolated in the intensive care unit (ICU) than were susceptible strains (P<.001; relative hazard, 3.77). The positive clinical samples were of various types (eg, nonprotected respiratory samples [43%] and blood [5%]), but no difference in type of source was seen between resistant and susceptible strains. A simultaneous analysis of pulsotypes and antibiotypes proved that the outbreak in the ICU in 2003 could be linked to an initially endemic clone that had been isolated in 2001. Furthermore, a second clone responsible for an extended-spectrum beta -lactamase phenotype was sporadically present in our institution. Although the strains isolated in the burn unit were also genetically related one to another, the specific responsible clone only appeared in 2003. CONCLUSION: Several multidrug-resistant clones can coexist endemically for several years and can be detected during an outbreak by close survey of epidemic sources.

Acinetobacter Infections↗

[Course and outcome of surgical infections complicated with sepsis].

A retrospective study of 594 medical histories of patients with surgical infections suggested diagnosis of sepsis in 18.2% cases according to ACCP/SCCM criteria (1992). Pulmonary and abdominal sepsis prevailed and led to higher lethality. Sepsis developed most often as nosocomial infection caused primarily by Acinetobacter spp. and Ps.aeruginosa. Most patients were males aged from 40 to 60 years. The main causes of lethality were septic shock (49.3%) and multiple organ failure syndrome (21%). Time of surgical sanation, antibacterial therapy and its adequacy correlated with the disease outcome.

Acinetobacter Infections↗

[Endocarditis on cardiac pacemaker endocavitary electrodes. Apropos of 7 cases].

The authors report 7 cases of endocarditis on cardiac pacing catheters observed out of a total of 2 950 primary implantations and 1 600 pacemaker replacements. This is a rare condition (0.15%) but carries a poor prognosis as it usually occurs in elderly patients and demands aggressive management. The presence of multiple pacing catheters and surgical contamination due to manipulation of the pulse generator (reimplantation, pacemaker replacement) are predisposing factors. The infecting organism in these cases was a staphylococcus. One case of metastatic infection was also observed (acinetobacter). Ablation of the septic endocarditic material under effective, prolonged, double antibiotherapy is essential. Recently implanted electrodes were withdrawn by simple traction in 2 cases. This manoeuvre was attempted initially in all cases but stopped when chest pain or runs of ventricular extrasystoles occurred. Open heart explantation of pacing electrodes adherent to the ventricular apex was performed in 5 patients. Cardiopulmonary bypass without cardiac standstill enabled dissection of the fibrous rings surrounding the catheter after purging the blood from the atrial and ventricular cavities. In one patient, associated tricuspid valve endocarditis was found and valvular replacement was performed with a bioprosthesis. Endocardial pacing was replaced by epicardial pacing in patients with permanent AV block. The prognosis of this condition is poor; there were 2 deaths in this series of 7 patients.

Acinetobacter Infections↗