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PubMed2003

Seven novel species of Acinetobacter isolated from activated sludge.

Thirteen isolates of Acinetobacter were obtained from activated sludge plants in Victoria, Australia. Earlier 16S-23S rDNA genomic fingerprinting and partial 16S rDNA sequence data had suggested that these isolates might contain previously undescribed species. This view was confirmed here. A polyphasic taxonomic approach involving phenotypic characterization, near-complete 16S rDNA sequence data and DNA-DNA hybridization analyses support the view that seven novel genomic species can be differentiated in this group of isolates. However, when fluorescence in situ hybridization (FISH) studies were performed with a 16S-rRNA-targeted probe specific for the genus Acinetobacter, used to identify Acinetobacter in activated sludge plants, all these strains responded positively. This suggests that these isolates would not have been missed in earlier FISH studies where their role as polyphosphate-accumulating bacteria has been questioned. This report describes these isolates and proposes that they be named Acinetobacter baylyi (type strain B2T = DSM 14961T = CIP 107474T), Acinetobacter bouvetii (type strain 4B02T = DSM 14964T = CIP 107468T), Acinetobacter grimontii (type strain 17A04T = DSM 14968T = CIP 107470T), Acinetobacter tjernbergiae (type strain 7N16T = DSM 14971T = CIP 107465T), Acinetobacter towneri (type strain AB1110T = DSM 14962T = CIP 107472T), Acinetobacter tandoii (type strain 4N13T = DSM 14670T = CIP 107469T) and Acinetobacter gerneri (type strain 9A01T = DSM 14967T = CIP 107464T).

Acinetobacter↗
PubMed2006

Distinct antimicrobial resistance patterns and antimicrobial resistance-harboring genes according to genomic species of Acinetobacter isolates.

Using 58 isolates of Acinetobacter species recovered from a university hospital between August 2004 and March 2005, we performed genomic identification by amplified rRNA gene restriction analysis (ARDRA) and investigated the existence of metallo-beta-lactamase (MBL) producers and extended-spectrum beta-lactamase (ESBL) producers. Genomic species identification of Acinetobacter strains using ARDRA showed that 40 strains were genomic species 2 (Acinetobacter baumannii), 9 were 13 sensu Tjernberg and Ursing (13TU), 5 were Acinetobacter phenon 6/ct 13TU, and 4 were Acinetobacter genospecies 3. Among 58 strains, 13 isolates were MBL producers carrying bla(IMP-1) or bla(VIM-2) and 13 isolates were ESBL producers carrying bla(PER-1). Notably, the MBL producers were mostly 13TU, Acinetobacter phenon 6/ct 13TU, and Acinetobacter genospecies 3, which showed susceptibility to ciprofloxacin and ampicillin-sulbactam. However, 12 of 13 strains carrying bla(PER-1) were A. baumannii, showing multidrug resistance. The data revealed that the antimicrobial resistance patterns and resistance-harboring genes of Acinetobacter species are remarkably distinct according to the genomic species of Acinetobacter isolates.

Acinetobacter↗
PubMed1996

Influence of relative humidity and suspending menstrua on survival of Acinetobacter spp. on dry surfaces.

Acinetobacter spp. are being reported with increasing frequency as a cause of nosocomial infection and have been isolated from the skin of healthy individuals, patients, hospital staff, dry nonbiotic objects, and different pieces of medical equipment. Factors affecting the survival of Acinetobacter spp. under conditions closely similar to those found in the hospital environment were investigated in the present study to help us understand the epidemiology of nosocomial Acinetobacter infection. Bacterial cells were suspended in distilled water or bovine serum albumin and were dried onto glass coverslips and kept at different relative humidities. Cells washed from coverslips were used to determined viable counts. Freshly isolated strains of Acinetobacter spp. belonging to the clinically important Acinetobacter calcoaceticus-Acinetobacter baumannii complex were found to be more resistant to drying conditions (e.g., 30 days for A. baumannii 16/49) than American Type Culture Collection strains (e.g., 2 days for A. baumannii ATCC 9955). The majority of strains belonging to the Acb complex had survival times similar to those observed for the gram-positive organism Staphylococcus aureus tested in the experiment. Survival times were prolonged for almost all the strains tested when they were suspended in bovine serum albumin (e.g., 60 days for A. baumannii R 447) compared with those for strains suspended in distilled water (11 days for R 447). The survival times for strains at higher relative humidity (31 or 93%) were longer than those for strains of Acinetobacter kept at a relative humidity of 10% (11 days at 31% relative humidity and 4 days at 10% relative humidity for R447). These findings are consistent with the observed tendency of Acinetobacter spp. to survive on dry surfaces, and they can be transferred not only by moist vectors but also under dry conditions in a hospital environment during nosocomial infection outbreaks. The results obtained in the experiment support the previously suggested airborne spread of Acinetobacter spp. in hospital wards and repeated outbreaks after incomplete disinfection of contaminated dry surfaces.

Acinetobacter↗
PubMedDate not supplied

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.

Acinetobacter↗
PubMed2002

Comparative studies of the Acinetobacter genus and the species identification method based on the recA sequences.

The recA gene is indispensable for a maintaining and diversification of the bacterial genetic material. Given its important role in ensuring cell viability, it is not surprising that the RecA protein is both ubiquitous and well conserved among a range of prokaryotes. Previously, we reported Acinetobacter genomic species identification method based on PCR amplification of an internal fragment of the recA gene with subsequent restriction analysis (RFLP) with HinfI and MboI enzymes. In present study, the PCR products containing the internal fragment of the recA gene, for 25 Acinetobacter strains belonging to all genomic species, were sequenced. Based on the nucleotide sequences the restriction maps and phylogenetic tree were prepared. The restriction maps revealed that Tsp509I restriction enzyme is the most discriminating for RFLP. To verify the computer analysis, the amplified DNAs from all reference genomic species available (43 strains) and 34 clinical strains were digested with each of the three restriction endonucleases mentioned. The results of digestion confirmed the computer analysis. The reconstructed phylogenetic tree showed linkages between genomic species 1 (Acinetobacter calcoaceticus), 2 (Acinetobacter baumannii), 3, 'between 1 and 3', TU13 and 'close to TU13'; genomic species 4, 6, BJ13, BJ14, BJ15, BJ16 and BJ17; genomic species 7 (Acinetobacter johnsonii) and TU14; genomic species 10 and 11; genomic species 8 (Acinetobacter Iwoffii), 9, 12 (Acinetobacter radioresistens) and TU15; and genomic species 5 (Acinetobacter junii). It is interesting that one branch in the phylogenetic tree contains haemolytic species-genomic species 4 (A. haemolyticus), BJ13, BJ14, BJ15, BJ16 and BJ17. The proposed genotypic method clearly revealed that the RFLP profiles obtained with Tsp509I enzyme might be useful for species identification of Acinetobacter strains. In this context, recA/RFLP genotypic method should be seen as an ideal preliminary screening method for large numbers of isolates, with the ultimate confirmatory role reserved for DNA hybridization analysis.

Acinetobacter↗
PubMed1998

Surveillance of an adult intensive care unit for long-term persistence of a multi-resistant strain of Acinetobacter baumannii.

Sporadic infections with Acinetobacter spp., punctuated with prolonged outbreaks of infection involving larger numbers of patients and a particular epidemic strain of Acinetobacter baumannii, have occurred in the adult intensive care unit (ICU) of Nottingham University Hospital since 1985. The aim of this study was to screen patients admitted to the ICU for three or more days during a non-outbreak period in 1994-1995 and to use DNA fingerprinting techniques to compare any isolates of Acinetobacter spp. with isolates obtained from the same ICU during the previous ten years. In the present study, almost 20% of the ICU patients screened during 1994-1995 became colonized with Acinetobacter spp. The commonest species isolated from patients was Acinetobacter baumannii; five different strains were identified by random amplified polymorphic DNA fingerprinting, including the epidemic strain responsible for outbreaks of infection in 1985-1986 and 1992-1993. Environmental sampling yielded Acinetobacter spp. from one or more samples on four occasions; Acinetobacter radioresistens was the commonest species isolated, and Acinetobacter baumannii (not the epidemic strain) was isolated on only one occasion from the environment. The long-term persistence of a potentially epidemic strain in the ICU, even during a non-outbreak period, indicates a need for continued vigilance. Consequently, periodic patient and environmental surveillance, combined with typing of isolates, is recommended for ICUs where significant outbreaks of Acinetobacter infection have occurred in the past.

Acinetobacter↗
PubMed1996

Phylogenetic analysis of Acinetobacter strains based on the nucleotide sequences of gyrB genes and on the amino acid sequences of their products.

Partial nucleotide sequences of the gyrB genes (DNA gyrase B subunit genes) of 15 Acinetobacter strains, including the type and reference strains of genomic species 1 to 12 (A. calcoaceticus [genomic species 1], A. baumannii [genomic species 2], Acinetobacter genomic species 3, A. haemolyticus [genomic species 4], A. junii [genomic species 5], Acinetobacter genomic species 6, A. johnsonii [genomic species 7], A. lwoffii [genomic species 8], Acinetobacter genomic species 9, Acinetobacter genomic species 10, Acinetobacter genomic species 11, and A. radioresistens [genomic species 12]), were determined by sequencing the PCR-amplified fragments of gyrB. The gyrB sequence homology among these Acinetobacter strains ranged from 69.6 to 99.7%. A phylogenetic analysis, using the gyrB sequences, indicates that genomic species 1, 2, and 3 formed one cluster (87.3 to 90.3% identity), while genomic species 8 and 9 formed another cluster (99.7% identity). These results are consistent with those of DNA-DNA hybridization and of biochemical systematics. On the other hand, the topology of the published phylogenetic tree based on the 16S rRNA sequences of the Acinetobacter strains was quite different from that of the gyrB-based tree. The numbers of substitution in the 16S rRNA gene sequences were not high enough to construct a reliable phylogenetic tree. The gyrB-based analysis indicates that the genus Acinetobacter is highly diverse and that a reclassification of this genus would be required.

Acinetobacter↗
PubMed2006

Sequencing of the rpoB gene and flanking spacers for molecular identification of Acinetobacter species.

Acinetobacter species are defined on the basis of several phenotypic characters, results of DNA-DNA homology, and more recently, similarities or dissimilarities in 16S rRNA gene sequences. However, the 16S rRNA gene is not polymorphic enough to clearly distinguish all Acinetobacter species. We used an RNA polymerase beta-subunit gene (rpoB)-based identification scheme for the delineation of species within the genus Acinetobacter, and towards that end, we determined the complete rpoB gene and flanking spacer (rplL-rpoB and rpoB-rpoC) sequences of the 17 reference strains of Acinetobacter species and 7 unnamed genomospecies. By using complete gene sequences (4,089 bp), we clearly separated all species and grouped them into different clusters. A phylogenetic tree constructed using these sequences was supported by bootstrap values higher than those obtained with 16S rRNA or the gyrB or recA gene. Four pairs of primers enabled us to amplify and sequence two highly polymorphic partial sequences (350 and 450 bp) of the rpoB gene. These and flanking spacers were designed and tested for rapid identification of the 17 reference strains of Acinetobacter species and 7 unnamed genomospecies. Each of these four variable sequences enabled us to delineate most species. Sequences of at least two polymorphic sequences should be used to distinguish Acinetobacter grimontii, Acinetobacter junii, Acinetobacter baylyi, and genomic species 9 from one another. Finally, 21 clinical isolates of Acinetobacter baumannii were tested for intraspecies relationships and assigned correctly to the same species by comparing the partial sequences of the rpoB gene and its flanking spacers.

Acinetobacter↗
PubMedDate not supplied

Acinetobacter infection in neurosurgical intensive care patients.

BACKGROUND: This study was performed to analyse the incidence of Acinetobacter infections in neurosurgical patients in the postoperative period. METHODS: Two thousand three hundred and twenty postoperative cranial neurosurgical intensive care unit (ICU) patients were studied from March 1995 to August 1996; 419 patients had a variety of infections and 42 patients had multiple infections. Acinetobacter was isolated in 103 patients (24.6% of total patients infected and 4.4% of total patients analysed). Statistical analyses were performed to identify the risk factors, antibiotic sensitivity and outcome of therapy of Acinetobacter infection. RESULTS: Acinetobacter infection was not significantly related to the length of hospital stay prior to surgery but was related significantly to the length of stay in the ICU after surgery. Acinetobacter was isolated from sputum/tracheal secretions in 47/103 (45.6%), followed by cerebrospinal fluid [24/103 (23.3%)], urine [15/103 (14.56%)] and blood [15/103 (11.65%)]. Acinetobacter infection was present in 54 (3.21%) of 1680 patients who had undergone routine/elective surgery and in 49 (7.66%) of 640 patients following emergency surgery. Elective/supportive ventilation for > 5 days, external ventricular cerebrospinal fluid drainage for > 5 days, intracranial pressure monitoring and prolonged indwelling Foley's urinary catheter during the perioperative period were independent risk factors (p < 0.005). Acinetobacter isolated from sputum/tracheal secretions were mostly sensitive to amikacin, cefotaxime and ceftriaxone; while those grown from the cerebrospinal fluid were more often sensitive to ciprofloxacin, amikacin and netilmycin. Twenty-four patients succumbed to Acinetobacter infection; in 11 of these patients the organism was resistant to all antibiotics. CONCLUSION: Acinetobacter is an important nosocomial infection in neurosurgical intensive care patients.

Acinetobacter Infections↗
PubMed2005

[Infections caused by Acinetobacter spp. in critically ill ICU patients].

INTRODUCTION: To determine the frequency of infections caused by Acinetobacter spp. in critically ill patients admitted to Spanish intensive care units (ICUs) and to assess the clinical features and outcome. PATIENTS AND METHOD: Prospective, observational, multicenter study. Patients admitted for one or two months to ICUs participating in the Spanish Nosocomial Surveillance Study (ENVIN project) between 1997 and 2003 were included. Patients were classified into the following groups: infected by Acinetobacter spp., infected by other pathogens, and uninfected. RESULTS: In 343 (9.9%) patients from among 3,450 with nosocomial infection, Acinetobacter spp. was one of the pathogens identified in 406 episodes (cumulative incidence, 1.2 episodes per 100 patients). A. baumannii was the predominant species in 357 cases (87.9%). Variables significantly associated with selection of Acinetobacter spp. were medical (OR: 2.47; 95% CI: 1.24-4.91) or traumatic underlying disease (OR: 4.40; 95% CI: 2.20-8.80) and ICU stay (OR: 1.03; 95% CI: 1.02-1.04). The overall mortality rate in ICU patients with infection (31.1%) was similar to that of patients with Acinetobacter spp. infections (31.5%), although in both cases it was significantly higher than mortality in uninfected patients (10.7%). ICU mortality rates in patients with imipenem-resistant and imipenem-sensitive Acinetobacter spp. infections were not significantly different (33.3% vs. 30.0%; p = 0.7283). CONCLUSIONS: Acinetobacter spp. were present in 9.9% of patients with ICU-acquired infection. There were no significant differences in ICU mortality rates between patients with Acinetobacter spp. infection and patients with infections caused by other microorganisms.

APACHE↗
PubMedDate not supplied

Community-acquired Acinetobacter meningitis in adults.

Community-acquired Acinetobacter meningitis in adults is an extremely rare infection of the central nervous system (CNS). Here we report one adult case of this rare CNS infection and review the clinical data of another seven cases reported in the English language literature. In total, eight patients (six men and two women) aged between 19 and 63 years were studied. The causative pathogen in our patient was Acinetobacter baumannii; in the other reported cases they were most likely Acinetobacter Iwoffii, Acinetobacter johnsonii, Acinetobacter junii, a genomic species 3 or 6. No underlying disease was found in seven of the eight cases and six of the eight patients acquired the infections before the age of 30 years. Fever and consciousness disturbance were the most common clinical manifestations. Waterhouse-Friderichsen syndrome (WFS) was found in two cases. Unlike the Acinetobacter strains found in nosocomial infections, the strain of Acinetobacter meningitis in the community-acquired case did not show multiple antibiotic resistance. Most adult patients with community-acquired Acinetobacter meningitis can be saved by timely therapy with appropriate antibiotics before deterioration of the systemic condition and impairment of consciousness.

Acinetobacter↗
PubMed1982

Progressive resistance in a single strain of Acinetobacter calcoaceticus recovered during a nosocomial outbreak.

A study was undertaken to investigate a nosocomial outbreak of acinetobacter calcoaceticus. The outbreak occurred in a shock-trauma intensive care unit (ICU) during a 6-month period and involved a total of 37 cases. Although no deaths were attributable to Acinetobacter, 60% of patients from whom Acinetobacter was isolated were determined to have a lower respiratory tract infection. A significant difference (p less than 0.05) was noted between the length to stay in the unit of patients who acquired Acinetobacter (mean 23.9 days) and of those who remained free of the organism (mean 2.58 days). The average day on which cultures first became positive was 14.85. During the last 3 months of the outbreak, the ICU Acinetobacter isolates developed an unusual pattern of aminoglycoside resistance that differed significantly (p less than 0.001) from the sensitivities of non-ICU Acinetobacter isolates. No plasmids could be detected in selected aminoglycoside-resistance Acinetobacter. Pseudomonas aeruginosa isolated concurrently from patients with Acinetobacter showed no abnormal variation in antimicrobial sensitivities. These findings were interpreted to mean that the outbreak was the result of the persistence of a single strain of A. calcoaceticus within the ICU. Termination of the outbreak was attributed to initiation of control measures.

Acinetobacter↗
PubMed2001

Emergence of multi-drug-resistant Acinetobacter anitratus species in neonatal and paediatric intensive care units in a developing country: concern about antimicrobial policies.

Antimicrobial abuse is a serious risk factor for the emergence of multi-drug-resistant (MDR) pathogens. We report on the emergence of multi-drug-resistant Acinetobacter anitratus species over two 8-week periods in 1999 in the neonatal and paediatric intensive care units (NICU and PICU) of King Edward VII Hospital, Durban, South Africa. The source, transmission dynamics, microbiological evaluations, antibiotic utilization patterns and outcome were evaluated. MDR Acinetobacter anitratus was isolated from different body sites in 23 infants less than 2 months of age, 18 in the PICU and five in the NICU. The mortality was 56.5% and two survivors required re-admission. Ten of the 23 cases had entered the ICU with MDR Acinetobacter anitratus. Eleven of the study infants had received broad-spectrum antimicrobial agents before entering the ICU, while all infants with nosocomially acquired MDR Acinetobacter anitratus had received broad-spectrum antimicrobial agents. All the surgical cases with MDR Acinetobacter anitratus died. Microbiological data from both ICUs for 1999 indicated that gram-negative bacteria accounted for two-thirds of isolates, Acinetobacter anitratus and Klebsiella pneumoniae accounting for 33% and 27% of the isolates, respectively. Only 53% and 57% of all Acinetobacter spp isolates were susceptible to piperacillin/tazobactam and carbepenems, respectively. MDR Acinetobacter anitratus is an emerging problem to which antimicrobial abuse contributes.

Acinetobacter↗
PubMed2001

Association of acinetobacter species with contact lens-induced adverse responses.

PURPOSE: To determine the levels of Acinetobacter species associated with normal soft contact lens wear and to determine whether Acinetobacter species are involved in adverse reactions that occur during contact lens wear. METHODS: Patients wore soft contact lenses on an extended-wear basis. The bacteria on lenses and ocular swabs during asymptomatic and symptomatic lens wear were identified using standard microbiologic methods. RESULTS: Acinetobacter species were isolated and identified from 16 (13%) of 126 patient samples. Greater numbers of Acinetobacter species were isolated from lenses of patients experiencing adverse responses than from asymptomatic patients. Acinetobacter species were isolated from patients experiencing symptomatic adverse responses in 4 (13%) of 32 cases. CONCLUSION: It appeared that Acinetobacter species colonized the eye of extended contact lens wearers at a time when the normal functioning of the eye was compromised by contact lens wear. When Acinetobacter species were in high numbers on a contact lens, an adverse response occurred. This may implicate Acinetobacter species as a contributing factor to adverse responses associated with contact lens wear.

Acinetobacter↗
PubMed1995

Clinical and epidemiological features of an outbreak of acinetobacter infection in an intensive therapy unit.

Sporadic examples of infection with multi-resistant Acinetobacter spp. have occurred in Nottingham hospitals since at least 1977, punctuated by more prolonged outbreaks involving larger numbers of patients, particularly those confined to the intensive therapy unit (ITU) with severe underlying disease. In the most recent outbreak, 11 patients were infected with multi-resistant Acinetobacter strains and 26 patients were colonised. Four of the infected patients died directly or indirectly from infection with multi-resistant Acinetobacter spp., either while in the ITU or after discharge to a general ward. The mean interval from admission to the first isolation of a multi-resistant Acinetobacter strain was 6.7 and 12.1 days in the infected and colonised groups, respectively. Multi-resistant Acinetobacter strains were isolated most frequently from the respiratory tract, and eight patients had probable or suspected pneumonia caused by a multi-resistant Acinetobacter sp. All infected patients were treated with imipenem, with or without an aminoglycoside, except one patient who died before a diagnosis of acinetobacter infection was confirmed. Multi-resistant Acinetobacter spp. were isolated from various environmental sites in the ITU, and patient and environmental isolates were found to be related closely by biotyping, antibiograms, pulsed-field gel electrophoresis of chromosomal fingerprints and ribotyping. The outbreak was controlled ultimately by transfer of infected or colonised patients to an isolation cubicle, cohort nursing, emphasis on the importance of hand washing before and after patient contact and when handling case notes, and the use of disposable aprons and gowns during patient contact.(ABSTRACT TRUNCATED AT 250 WORDS)

Acinetobacter↗
PubMedDate not supplied

Acinetobacter infections in patients with human immunodeficiency virus infection: microbiological and clinical epidemiology.

BACKGROUND: We evaluated the role of complications caused by Acinetobacter spp. in the setting of HIV infection. METHODS: Clinical records of 1,923 consecutive HIV-infected patients hospitalized in a 9-year period were retrospectively reviewed, in order to identify all cases of Acinetobacter spp. complications, and to assess their occurrence and outcome according to several epidemiological, clinical and laboratory parameters. RESULTS: Ten patients out of 1,923 (0.52%) developed Acinetobacter spp. infections: sepsis in four cases, urinary tract infection in three, pneumonia in two and septicaemic pneumonia in the remaining patient. All patients were severely immunocompromised, as shown by a mean CD4+ lymphocyte count of 122 cells/microl and a frequent prior diagnosis of AIDS. As opposed to other infections, septicaemia was associated with a significantly lower CD4+ cell count and a more frequent occurrence of neutropenia. Hospital-acquired Acinetobacter spp. infections were significantly more frequent than community-acquired ones, and prevailingly involved patients with AIDS and leucopenia, being responsible for frequent blood dissemination. Antimicrobial, corticosteroid and cotrimoxazole treatment were frequently carried out during the month preceding disease onset. Antibiotic susceptibility studies proved the complete resistance of microbial isolates to ampicillin and cephalothin and poor sensitivity to second-generation cephalosporins and gentamicin, while greater susceptibility was shown to ceftazidime, netilmicin and amikacin, followed by piperacillin, cotrimoxazole and quinolones. Appropriate antimicrobial treatment led to clinical and microbiological cure in all cases, with no related mortality or relapses. CONCLUSIONS: Since only 23 episodes of HIV-associated Acinetobacter spp. infections have been described to date in 11 different reports (nine cases of bacteraemia, eight of pneumonia, two of urinary tract involvement, one of intravenous access device infection, one of meningitis and two with unspecified localization), our series represents the largest one dealing with HIV-associated Acinetobacter spp. infections. According to our experience, Acinetobacter spp. may be responsible for appreciable morbidity among patients with HIV infection, above all when a low CD4+ cell count, neutropenia and hospitalization are present. Clinicians and microbiologists who work in the field of HIV infection should consider the potential pathogenic role of Acinetobacter spp. organisms even in the absence of some presumed risk factors, because of the relationship between these infections and immunodeficiency, hospitalization, other infectious complications, prior antibiotic and steroid treatment and extended antimicrobial resistance patterns.

Acinetobacter↗
PubMedDate not supplied

Prevalence and in-vitro antimicrobial susceptibility patterns of Acinetobacter strains isolated from patients in intensive care units.

Fifty-six Acinetobacter species strains (49 Acinetobacter baumanii, 5 Acinetobacter calcoaceticus, 2 Acinetobacter iwoffii) were detected using both conventional methods and gas chromatography of bacterial fatty acids with the MIDI Sherlock Microbial Identification System. The susceptibilities of these strains to 16 antimicrobial agents were investigated by the disc-diffusion method according to the National Committee for Clinical Laboratory Standards. The production of extended-spectrum beta-lactamases (ESBLs) and inducible beta-lactamases (IBLs) by the strains were investigated by the double-disc-synergy and disc-approximation methods, respectively. Imipenem was the most effective agent for Acinetobacter baumanii strains (95.9% of strains were sensitive), while meropenem and netilmicin showed moderate activity (87.7% and 79.6% of strains, respectively, responded). Acinetobacter baumanii strains were less sensitive to cefoperazone-sulbactam (53.1%), ofloxacin (51.0%), ciprofloxacin (42.8%), and amikacin (36.7%). Acinetobacter calcoaceticus and Acinetobacter iwoffii strains were sensitive to imipenem, meropenem and netilmicin. IBLs and ESBLs were produced, respectively, by 8.9% and 7.1% of all bacterial strains. The strains isolated were sufficiently sensitive to imipenem, but not to ofloxacin or ciprofloxacin, and were very resistant to amikacin.

Acinetobacter↗
PubMed1999

Distribution of Acinetobacter species on skin of healthy humans.

The distribution of the 19 currently known genospecies of Acinetobacter on human skin, i.e. forehead, forearm and toe webs, was determined. Three selective media were compared for their specificity for all genospecies of Acinetobacter. A minimal-salts agar supplemented with 1% acetate proved to be more efficient than the Leeds medium for the isolation of most genospecies in mixed culture with other bacterial species. Acinetobacter isolates were provisionally identified using biochemical tests and the DNA transformation assay of Juni. Genospecies identification was performed using amplified ribosomal DNA restriction analysis, and duplicate isolates of the same genospecies from individuals were ruled out by random amplified polymorphic DNA analysis. Over 40% of 192 healthy volunteers carried Acinetobacter spp. at one or more body sites, and the frequencies of colonisation were as follows: forearm (51%), forehead (47%) and toe web (34%). Genospecies 8/9 (Acinetobacter lwoffii) was the most common (61%), followed by genospecies 15BJ and 12 (Acinetobacter radioresistens) at 12.5% and 8%, respectively. The Acinetobacter baumannii-Acinetobacter calcoaceticus group (genospecies 1, 2, 3 and 13TU) that predominates in hospital-acquired infections was found in only one individual.

Acinetobacter↗