Characterization of multidrug-resistant Acinetobacter ssp. strains isolated from medical intensive care units in Cali - Colombia / Caracterización de cepas de Acinetobacter spp. resistentes a múltiples fármacos aisladas de unidades de cuidados intensivos en Cali - Colombia

Abstract Introduction: The extensive use of antibiotics has led to the emergence of multi-resistant strains in some species of the genus Acinetobacter. Objective: To investigate the molecular characteristics of multidrug-resistant of Acinetobacter ssp. strains isolated from 52 patients collected between March 2009 and July 2010 in medical intensive care units in Cali - Colombia. Methods: The susceptibility to various classes of antibiotics was determined by disc diffusion method, and the determination of the genomic species was carried out using amplified ribosomal DNA restriction analysis (ARDRA) and by sequencing of the 16s rDNA gene. Also, the genes of beta-lactamases as well as, integrases IntI1 and IntI2 were analyzed by PCR method. Results: The phenotypic identification showed that the isolates belong mainly to A. calcoaceticus- A. baumannii complex. All of them were multi-resistant to almost the whole antibiotics except to tigecycline and sulperazon, and they were grouped into five (I to V) different antibiotypes, being the antibiotype I the most common (50.0%). The percent of beta-lactamases detected was: blaTEM (17.3%), blaCTX-M (9.6%), blaVIM (21.2%), blaIMP (7.7%), blaOXA-58 (21.2%), and blaOXA-51 (21.2%). The phylogenetic tree analysis showed that the isolates were clustering to A. baumannii (74.1%), A. nosocomialis (11.1%) and A. calcoaceticus (7.4 %). Besides, the integron class 1 and class 2 were detected in 23.1% and 17.3% respectively. Conclusion: The isolates were identified to species A. baumanii mainly, and they were multiresistant. The resistance to beta-lactams may be by for presence of beta-lactamases in the majority of the isolates.

Resumen Introducción: El uso extensivo de antibióticos ha llevado a la emergencia de cepas multirresistentes en algunas especies del género Acinetobacter. Objetivo: Investigar las características moleculares de resistencia a múltiples fármacos de cepas aisladas de Acinetobacter spp. colectadas entre marzo de 2009 y julio de 2010 en 52 pacientes de unidades de cuidados intensivos en Cali - Colombia. Métodos: La susceptibilidad a diversas clases de antibióticos se determinó mediante el método de difusión de disco, y la determinación de la especie genómica se llevó a cabo usando un análisis de restricción de ADN ribosómico amplificado (ARDRA) y mediante la secuenciación del gen 16s de ADNr. Además, se analizaron por el método de PCR los genes de las beta-lactamasas, como también, las integrasas IntI1 e IntI2. Resultados: La identificación fenotípica mostró que los aislamientos pertenecen principalmente al complejo A. calcoaceticus - A. baumannii. Todos ellos eran multirresistentes a casi todos los antibióticos excepto tigeciclina y sulperazón, y se agruparon en cinco (I a V) antibitipos diferentes, siendo el antibiotipo I el más común (50%). El porcentaje de betalactamasas detectadas fue: blaTEM (17,3%), blaCTX-M (9,6%), blaVIM (21,2%), blaIMP (7,7%), blaOXA-58 (21,2%), blaOXA- 51 (21.2%). El análisis del árbol filogenético mostró que los aislados se agrupaban en A. baumannii (74.1%), A. nosocomialis (11.1%) y A. calcoaceticus (7.4%). Además, el integrón clase 1 y clase 2 se detectaron en 23.1% y 17.3% respectivamente. Conclusión: los aislamientos se identificaron principalmente como la especie A. baumanii, y fueron multirresistentes. La resistencia a los betalactámicos puede deberse a la presencia de betalactamasas en la mayoría de los aislamientos.

Glimpse into the genome sequence of a multidrug-resistant Acinetobacter pittii ST950 clinical isolate carrying the blaOXA-72 and blaOXA-533 genes in China

The development of carbapenem-resistant Acinetobacter species is of serious concern in the hospital settings and naturally occurring oxacillinase genes (blaOXA) have been identified in several Acinetobacter species. In this study, we report the genome sequence of A. pittii TCM178 belongs to ST950, a multidrug-resistant isolate that harbored the blaOXA-72 and blaOXA-533 genes simultaneous. The genome size was estimated to be 3,789,564 bp with 3,501 predicted coding regions, and G+C content is 37.60%. Our findings have raised awareness of the possible constitution of a reservoir for peculiar carbapenemase genes in A. pittii that may spread among other Acinetobacter species in China.

Draft genome sequence of Acinetobacter pittii ST643 shared by cystic fibrosis patients

Acinetobacter pittii has emerged as an important hospital pathogen that is associated with outbreaks and drug resistance. In cystic fibrosis (CF) patients, the detection of Acinetobacter spp. is rare; however, we isolated the A. pittii sequence type ST643 in several Brazilian CF patients treated in the same centre. The current study describes the draft genome of A. pittii ST643.

Antimicrobial susceptibility of acinetobacter clinical isolates and emerging antibiogram trends for nosocomial infection management

Abstract: Introduction: The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. METHODS: In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2%) specimens each, followed by the resistance to gentamicin in 670 (93.6%) isolates, and to imipenem in 651 (90.9%) isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. CONCLUSIONS: The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.

Excess body weight in children may increase the length of hospital stay

OBJECTIVES: To investigate the prevalence of excess body weight in the pediatric ward of University Hospital and to test both the association between initial nutritional diagnosis and the length of stay and the in-hospital variation in nutritional status. METHODS: Retrospective cohort study based on information entered in clinical records from University Hospital. The data were collected from a convenience sample of 91 cases among children aged one to 10 years admitted to the hospital in 2009. The data that characterize the sample are presented in a descriptive manner. Additionally, we performed a multivariate linear regression analysis adjusted for age and gender. RESULTS: Nutritional classification at baseline showed that 87.8% of the children had a normal weight and that 8.9% had excess weight. The linear regression models showed that the average weight loss z-score of the children with excess weight compared with the group with normal weight was −0.48 (p = 0.018) and that their length of stay was 2.37 days longer on average compared with that of the normal-weight group (p = 0.047). CONCLUSIONS: The length of stay and loss of weight at the hospital may be greater among children with excess weight than among children with normal weight. .

Increasing Carbapenem-Resistant Gram-Negative Bacilli and Decreasing Metallo-beta-Lactamase Producers over Eight Years from Korea

The trends and types of carbapenemase-producing Gram-negative bacilli were analyzed from clinical specimens collected between 2005 and 2012 at a Korean teaching hospital. The proportions of carbapenem-resistant Acinetobacter spp. increased markedly to 66%. Metallo-beta-lactamase producers significantly decreased and the majority shifted from the bla(VIM-2) type to the bla(IMP-1) type.

High genetic diversity among Pseudomonas aeruginosa and Acinetobacter spp. isolated in a public hospital in Brazil

In Brazil and other regions of the world, Pseudomonas aeruginosa and Acinetobacter spp. have emerged as important agents of nosocomial infection and are commonly involved in outbreaks. The main objective of the present study was to evaluate the genetic relationship among P. aeruginosa and Acinetobacter spp. isolated from patients in a public university hospital in northwestern Paraná, Brazil, and report their antimicrobial resistance profile. A total of 75 P. aeruginosa and 94 Acinetobacter spp. isolates were phenotypically identified and tested for antibiotic susceptibility using automated methodology. Polymyxin B was tested by disk diffusion for P. aeruginosa. Metallo-β-lactamase (MBL) was detected using a disk approximation test. Genotyping was performed using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Approximately 55% of the P. aeruginosa isolates and 92% of the Acinetobacter spp. isolates were multiresistant, but none were MBL-producers. ERIC-PCR revealed the presence of small clusters of carbapenem-resistant Acinetobacter spp., most likely OXA-type carbapenemase producers. Furthermore, high genetic diversity in P. aeruginosa and Acinetobacter spp. clinical isolates was observed, suggesting that cross-transmission is not very frequent in the studied hospital.

No Brasil, bem como em outras regiões do mundo, Pseudomonas aeruginosa e Acinetobacter spp. surgiram como importantes agentes de infecção nosocomial e são comumente envolvidos em surtos. O objetivo principal deste estudo foi descrever a relação genética de P. aeruginosa e Acinetobacter spp. isoladas de pacientes internados em hospital universitário público do noroeste do Paraná - Brasil e reportar o perfil de resistência dessas bactérias. Um total de 75 P. aeruginosa e 94 Acinetobacter spp. isolados foi fenotipicamente identificado e testado para a suscetibilidade aos antibióticos por metodologia automatizada. A polimixina B foi testada por difusão em disco para P. aeruginosa. Metalo-β-lactamase (MBL) foi detectada por disco-aproximação. Análise genotípica foi realizada por enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Aproximadamente 55% dos isolados de P. aeruginosa e 92% de Acinetobacter spp. isolados foram multirresistentes, mas nenhum foi produtor de MBL. Os resultados de ERIC-PCR revelaram pequenos grupamentos de Acinetobacter spp. resistentes aos carbapenêmicos, provavelmente pela produção de carbapenemases do tipo OXA. Além disso, alta diversidade genética entre os isolados de P. aeruginosa e Acinetobacter spp. foi observada, sugerindo que a transmissão cruzada destas espécies bacterianas não é muito frequente em nosso hospital.

The Causes and Treatment Outcomes of 91 Patients with Adult Nosocomial Meningitis

BACKGROUND/AIMS: Frequent pathogens of nosocomial meningitis were investigated and the adequacy of empiric antibiotic therapy was assessed. Outcomes of nosocomial meningitis were also evaluated. METHODS: Ninety-one patients, who were diagnosed and treated for nosocomial meningitis at a single tertiary hospital in Daegu, Korea for 10 years, were included. Medical record and electronic laboratory data on the causative pathogens, antibiotics used, and outcomes were retrospectively investigated. RESULTS: Coagulase-negative Staphylococcus (40.9%) was the most common pathogen, followed by Acinetobacter (32.5%). Both were cultured as a single organism in cerebrospinal fluid (CSF). Seventy-eight patients (85.7%) had infections related to external ventricular drains (EVD). The most common empirical antibiotics were extended-spectrum beta-lactam antibiotics plus vancomycin (35/91, 38.6%). Of the 27 patients who had cultured Acinetobacter in CSF, 10 (37%) were given the wrong empirical antibiotic treatment. Seven of the 27 patients (26.9%) with cultured Acinetobacter died, and overall mortality of the 91 patients was 16.5%. In the multivariate analysis, the presence of combined septic shock (p < 0.001) and a persistent EVD state (p = 0.021) were associated with a poor prognosis. CONCLUSIONS: Acinetobacter is one of the leading pathogens of nosocomial meningitis and may lead to inadequate coverage of empiric antibiotic therapy due to increasing resistance. An EVD should be removed early in cases of suspected nosocomial meningitis, and carbapenem might be required for the poor treatment response.

Multidrug-Resistant Acinetobacter spp.: Increasingly Problematic Nosocomial Pathogens

Pathogenic bacteria have increasingly been resisting to antimicrobial therapy. Recently, resistance problem has been relatively much worsened in Gram-negative bacilli. Acinetobacter spp. are typical nosocomial pathogens causing infections and high mortality, almost exclusively in compromised hospital patients. Acinetobacter spp. are intrinsically less susceptible to antibiotics than Enterobacteriaceae, and have propensity to acquire resistance. A surveillance study in Korea in 2009 showed that resistance rates of Acinetobacter spp. were very high: to fluoroquinolone 67%, to amikacin 48%, to ceftazidime 66% and to imipenem 51%. Carbapenem resistance was mostly due to OXA type carbapenemase production in A. baumannii isolates, whereas it was due to metallo-beta-lactamase production in non-baumannii Acinetobacter isolates. Colistin-resistant isolates were rare but started to be isolated in Korea. Currently, the infection caused by multidrug-resistant A. baumannii is among the most difficult ones to treat. Analysis at tertiary care hospital in 2010 showed that among the 1,085 isolates of Acinetobacter spp., 14.9% and 41.8% were resistant to seven, and to all eight antimicrobial agents tested, respectively. It is known to be difficult to prevent Acinetobacter spp. infection in hospitalized patients, because the organisms are ubiquitous in hospital environment. Efforts to control resistant bacteria in Korea by hospitals, relevant scientific societies and government agencies have only partially been successful. We need concerted multidisciplinary efforts to preserve the efficacy of currently available antimicrobial agents, by following the principles of antimicrobial stewardship.

Species distribution and physiological characterization of Acinetobacter genospecies from healthy human skin of tribal population in India.

BACKGROUND: Various reports on distribution of Acinetobacter spp. from healthy human skin restricted to urban population. However, no such data is available from healthy human skin of tribal population not exposed to modern antibiotics during their life time. PURPOSE: Isolation, biotyping, distribution and physiological characterisation of Acinetobacter spp. from healthy human skin of tribal population. METHODS: Tribal population of Toranmal area of Satpuda Ranges, Maharashtra, India were sampled for ten body sites. Tentative Acinetobacter isolates were confirmed to the genus level by chromosomal DNA transformation assay and to species level using Bouvet and Grimont system. Novel physiological characteristics like pH, temperature and salt tolerance were studied. All strains were screened for production of various enzymes. RESULTS: One hundred and eighteen strains were isolated, which belonged to nine Acinetobacter genospecies. A. haemolyticus was most abundant followed by A. calcoaceticus and A. genospecies 1-3. Higher percentage of Acinetobacter was recovered from skin of nose, Pawara tribe and female volunteers. They showed wide variation in temperature, salt and pH tolerance. Most of the strains could produce enzymes viz, lipase, esterase, urease and amylase. CONCLUSIONS: Acinetobacter spp. belonging to nine genospecies were obtained in the present study. Physiological characteristics including high salt, temperature and acidic pH tolerance were helpful to differentiate between the commensal and pathogenic species of Acinetobacter genus.

Plasmid distribution & antimicrobial susceptibility patterns of Acinetobacter genospecies from healthy skin of a tribal population in western India.

BACKGROUND & OBJECTIVE: Acinetobacter spp., the only Gram negative commensal found on human skin are emerging nosocomial pathogens, and are rapidly developing multiple drug resistance. Most studies in India and over the world are on clinical and environmental Acinetobacter isolates. The present investigation was undertaken to study plasmid distribution and antibiotic resistance profile of Acinetobacter genospecies isolated from healthy human skin of a tribal population from western India. METHODS: One hundred and eighteen strains of Acinetobacter spp. were isolated from healthy human skin and biochemically classified into nine genospecies. Plasmid profiles were determined using four standard methods with minor modifications and by a commercial kit. Molecular weights were determined by comparison with standard plasmids pUC19, pBR322, RP4 and molecular weight marker, V517. Antimicrobial susceptibility patterns of Acinetobacter genospecies to 30 antibiotics belonging to different groups was determined using Kirby Bauer method. RESULTS: All isolates, except two showed a maximum of three plasmids with molecular size 1.5 to 40 kb. Five different plasmid types were observed. Only eight strains had one or two stably maintained low molecular weight plasmids in addition to 40 kb plasmid seen in most of the strains. Quinolones and aminoglycosides were most active group followed by, cephalosporins and beta lactams. INTERPRETATION & CONCLUSION: Acinetobacter spp. isolated from the tribal skin flora had low number of plasmids as compared to clinical and environmental isolates. Acinetobacter spp. harbouring low molecular weight plasmids were found to be sensitive to most of the antibiotics tested suggesting these might be coding for some other novel properties or may be cryptic, whereas, those having 40 kb plasmid showed intermediate to low level resistance to some antibiotics.

Clinical and demographic features of infection caused by Acinetobacter species.

BACKGROUND: Recently, Acinetobacter emerged as an important pathogen and the prevalence of isolation has increased since the last two decades worldwide. AIMS: To determine Acinetobacter incidence, their clinical demography, antibiotyping and speciation. SETTINGS AND DESIGN: A study of the clinical samples submitted to microbiology laboratory of a teaching hospital over a period of 3 years (December 1994 through November 1997). MATERIALS AND METHODS: Identification, speciation and antibiotyping were performed for the isolates of Acinetobacter recovered from infective samples. Clinical demographic characteristics were studied retrospectively. RESULTS: Total 510 of 5391 (9.6%) of isolates were Acinetobacter, responsible for 71.2% (363 of 510) monomicrobial and 28.8% (147 of 510) polymicrobial infections. The organism was responsible for 156 (30.6%) cases of urinary tract infection and 140 (27.5%) cases of wound infection and was most prevalent in the intensive care unit (30.8%, 140 of 455). The crude mortality rate due to multi-drug resistant Acinetobacter septicemia was 7.9% (36 of 455). The isolates could be classified into 7 species, with A. baumannii being most predominant. No peculiar pattern during antibiotyping was observed, but most of them were multi-drug resistant. CONCLUSION: Multi-drug resistant Acinetobacter nosocomial infection has emerged as an increasing problem in intensive care units of the hospital, responsible for 7.9% deaths. The analysis of risk factors and susceptibility pattern will be useful in understanding epidemiology of this organism in a hospital setup.

Nosocomial infections due to Acinetobacter species: Clinical findings, risk and prognostic factors.

PURPOSE: Nosocomial infections caused by Acinetobacter species is of increasing concern in critically ill patients, and the risk factors for this infection are not well established. The present investigation was done to determine incidence of nosocomial Acinetobacter infections. Our study retrospectively attempts to find risk and prognostic factors for the nosocomial acquisition of Acinetobacter infection. METHODS: The medical records of 43 patients with Acinetobacter infection during two-year period (Oct1998-Oct2000) were reviewed to find the factors involved in the nosocomial acquisition of Acinetobacter. Acinetobacter isolates that were obtained from these patients were phenotypically typed using carbon assimilation tests. Antimicrobial susceptibility testing results were noted from the microbiology records. RESULTS: Acinetobacter baumannii accounted for 41.8% (n=18) of all the infections. By multivariate logistic regression analysis, only resistant antibiotype {(Ceftazidime- OR, 7.13 [95% CI, 1 to 46];p= 0.044); (Cefotaxime- OR, 6.09 [CI, 0.87 to 30];p = 0.045)} and mechanical ventilation (OR, 5.84 [CI, 0.83 to 31];p = 0.05) were found to be potential independent risk factors for mortality. Overall mortality rate was 33%. CONCLUSIONS: Most of A. baumannii isolates were multidrug resistant in our set up and infections due to them were associated with high mortality. Prevention of Multiple drug resistant (MDR) A. baumannii infections was achieved after discontinuation of cefotaxime in ICU. Infection with resistant clones and mechanical ventilation were found to be potential independent risk factors for mortality.

Characterization and changing minimum inhibitory concentration (MIC) of Acinetobacter species from a tertiary care setup.

128 isolates of Acinetobacter species from admitted and outdoor patients were subjected to biotyping and resistotyping. Resistance phenotype analysis included nine antibiotics and two betalactam inhibitor combination drugs. In 100 strains of Acinetobacter spp. ciprofloxacin, amikacin, cefotaxime and cefepime minimum inhibitory concentration (MIC) was done by agar dilution using NCCLS 2002 criteria. In forty-nine isolates MIC level was determined by E-strip also. Extended spectrum beta lactamase (ESBL) production was detected by double disc synergy technique. Inducible beta lactamases (IBL's) were detected by disc approximation method. The relationship between biotypes and resistance phenotype was analyzed. Majority of isolates (93.75%) were from admitted patients. The biotyping revealed Acinetobacter calcoaceticus-Acinetobacter baumannii complex (87.2%) to be the predominant species and they were isolated from tracheal aspirates of patients with ventilator associated pneumonia. By Kirby Bauer disc diffusion antimicrobial sensitivity testing Acinetobacter spp. were most sensitive to the combination of drug cefoperazone-sulbactam (95.6%) followed by meropenem (94.6%), piperacillin-tazobactam (92.6%). On screening incidence of Imipenem Nonsensitive Acinetobacter spp. (INSA) was (5.4%). Acinetobacter spp. were typable by six resistance phenotypes and six biotypes. Most common (66.6%) resistant phenotype of A. calcoaceticus-A. baumannii complex was susceptible to cefoperazone-sulbactam and or meropenem and or piperacillin-tazobactam. ESBL production was seen in 6% and IBL (Inducible Beta Lactamase) production was seen in 7% of Acinetobacter spp. The MIC90 for ciprofloxacin was =256 microg/ml, cefotaxime 512 microg/ml, cefepime 512 microg/ml, and amikacin 32 microg/ml. Multidrug resistance was seen in more than 90% of A. calcoaceticus-A. baumannii complex and 20% of Acinetobacter lwoffii. Acinetobacter spp. has other emerging novel mechanism of resistance that requires continuous research. Simpler, reproducible and reliable methods of biotyping and their subsequent correlation with resistotyping are more cost effective than molecular methods, which are available only in reference laboratories.

Characterization of Acinetobacter from clinical isolates at Gandhi memorial and associated hospitals, Lucknow.

The study was conducted in 4140 clinical samples sent to Microbiology department from different department of G.M. and associated hospitals. The samples included 2270 urine, 960 pus, 300 blood, 210 sputum, 180 CSF, 20 intercostal drainage tubes and 150 other swabs like vaginal and urethral, conjunctival smear 30, 10 ascitic fluids and 10 gastric aspirates. Apart from this, 30 specimens were collected from hospitals environment, like linen and trolley. From clinical samples, 43 acinetobacter strains (1.04%) were isolated. 17 strains (0.41%), were from pus, 12 (0.28%), from respiratory tract, 1, was (0.02%) from intercostal drainage secretions, urine 9 (0.22%), blood 1 (0.2%) and CSF 3 (.72%). From environmental samples, 7 strains (23.33%) were isolated. All the isolated strains were identified by routine biochemical tests. They were preserved in 1 % agar media for characterization. Characterization was done on the basis of growth at 37 degrees c, 41 degrees c and 44 degrees c, hemolysis, gelatin hydrolysis, acid from glucose, utilization of citrate, L-phenyl alanine, malonate, B-alanine, L-arginine, L-ornithine and L-aspartate. Among species identified Acinetobacter baumannii was 30 (69.67%), from clinical specimens and 5 (71.42%) from environment, Acinetobacter lwoffi was 10 (23.25%) from clinical specimen and 2 from environmental specimen, Acinetobacter hemolyticus was 3 (6.97%) and none from the environment. All the strains were resistant to penicillin. The sensitivity pattern showed gentamycin 64% sensitive, cotrimaxazole 42% cefotoxin 32% ciprofloxacine 26% and tetracycline 16%.

Comportamiento de acinobacter en los procesos infecciosos de los pacientes ingresados al HEALF de enero 2004 a diciembre de 2005 / Acinobacter behavior in the infectious processes of the patients entered the HEALF of January 2004 to December of 2005

El trabajo comportamiento de acinetobacter en los procesos infecciosos de pacientes ingresados al HEALF de enero de 2004- diciembre de 2005, se realizó con el objetivo de conocer el comportamiento de esta bacteria en nuestro medio ya que el acinetobacter ha surgido como un importante microorganismo a nivel intrahospitalario y uno de los mayores problemas de la infecciones producidas por esta bacteria es su tratamiento, por su amplia multiresistencia y por las pocas alternativas terapéuticas disponibles en la actualidad. Dicho estudio es descriptivo, de serie de casos. Para alcanzar este objetivo se estudiaron 452 pacientes a los que se aisló 528 Acinetobacter. Los procesos infewcciosos más frecuentes fueron: Sepsis de Herida Quirúrgica, Neumonías y Traqueóbronquitis. Los servicios más afectados fueron: Medicina Interna y de esta, la sala de UCI (Unidad de cuidados intensivos), Neurocirugía, principalmente lka sala de Neurocirugía Intermedios y cirugía plástica principalmente la sala de quemados. Según los resultados de Antibiogrma se encontró un alto grado de resistencia de la bacteria a los antibióticos disponibles en la Lista Básica de Medicamentos como son: Ceftriazona, Ampicilina, Amikacina, Ceftazidima y en menor grado de resistencia a los Carbapemenes (Imipenem, Meropenem)...>

Simplified panel of assimilation tests for identification of Acinetobacter species.

A total of 66 Acinetobacter isolates obtained from JIPMER hospital wards were subjected to phenotypic identification schemes involving 25-test and a simplified 13-test panel of carbon utilization or assimilation tests. Reference strains belonging to different DNA groups (n=24) were also tested. Identification was done using numerical approach based on a matrix constructed of phenotypic data published elsewhere and the strains were assigned to different DNA groups according to classification of Tjernberg & Ursing. Sixty-six strains tested represented 10 DNA groups in matrix of large test panel; at a probability level of 0.95. Much simplified scheme of 13 assimilation test panel failed to differentiate some isolates with in A. calcoaceticus-A. baumannii complex (Acb-complex) unlike extended panel. In all, from the large panel 95% of isolates were identified correctly among all the isolates and it did not identify 5% of isolates. From the small panel, a total of 89% of isolates were identified correctly and it could not identify 11% of isolates. Reduced number of assimilation tests to 13 from the large panel bought reduction in identification percentage rate by only 6%. It is impossible for many bacterial diagnostic labs worldwide to perform large panel of carbon utilization tests in routine practice. Simplified panel of assimilation tests suggested here seems to be the best alternative method for identification of Acinetobacter species.

Distribution and in vitro antimicrobial susceptibility of Acinetobacter species on the skin of healthy humans.

BACKGROUND: Acinetobacter spp. are ubiquitous in the environment and have emerged as important nosocomial pathogens. The distribution of Acinetobacter spp. In some temperate European countries has been reported. However, similar data from a tropical country such as India are not available. METHODS: Six body sites (antecubital fossa, axilla, forehead with hairline, neck, outer surface of nose and toe webs) from men and women volunteers were sampled with saline-soaked cotton swabs enriched in Baumann's enrichment medium. The isolates were identified to the genus level by chromosomal DNA transformation assay and to the species level by a 16-test biochemical system. The minimum inhibitory concentration for 39 antibiotics was determined by the two-fold agar dilution method. RESULTS: Seven genospecies of Acinetobacter were found at 6 body sites on healthy human skin. Acinetobacter lwoffii was the most dominant comprising 40% of the total number of isolates, followed by A. junii (35%) and A. haemolyticus (16.5%). The antecubital fossa had the highest colonization frequency (48.5%). The overall positivity rate of samples was higher from women (26.3%) compared to men volunteers (25%). Only two Acinetobacter genospecies 1-3 isolates were isolated while no A. radioresistens were isolated. Susceptibility testing revealed no major differences among the 7 Acinetobacter spp. tested. Fluoroquinolones were the most active, while low-to-intermediate resistance was exhibited towards beta-lactams and aminoglycosides. Acinetobacter spp. isolated from the skin showed susceptibility to commonly used antibiotics. CONCLUSION: Seven Acinetobacter genospecies were isolated from 6 different body sites from the skin of healthy human volunteers. Acinetobacter lwoffii was the dominant isolate. The rate of skin carriage was higher in men than in women and the maximally colonized site was the antecubital fossa. All the genospecies displayed susceptibility to most of the commonly used antimicrobials.