The skin as the source of Acinetobacter and Moraxella species occurring in blood cultures.

A study was made of the flora of the skin in hospital inpatients and healthy people to demonstrate the presence of non-fermenting Gram-negative rods of the Acinetobacter and Moraxella group. These organisms were found to be present on the skin of 34.3% of inpatients and occurred even more commonly in those patients with kidney disease. It was also present on the skin of 20% of a group of healthy members of staff. This rather high rate of skin carriage is thought to account for the not infrequent occurrence of this organism in blood cultures.     

Acinetobacter species as nosocomial pathogens

Conclusion In summary,Acinetobacter colonization or infection may originate from the patients' own flora under the pressure of antimicrobial selection, the hands of staff members, or contaminated equipment. Transmission ofAcinetobacter strains between patients occurs primarily via the hands of health care workers. In outbreak situations, colonized or infected patients and the inanimate environment, which can be secondarily contaminated, are the main reservoirs in the hospital setting for crosstransmission. However, colonized or infected patients seem to be the most important source of cross-contamination, as epidemic strains spread easily throughout different wards. Especially in prolonged outbreaks in which control efforts such as proper hand washing, glove changing, and restriction of antimicrobial agents are ineffective and specific sources such as contaminated equipment are not identified, the source of the epidemic strain is likely the patients' inanimate dry environment [45, 48].In outbreak situations it is necessary that isolatedAcinetobacter strains are identified to the genomic species level and then typed before epidemiological conclusions can be drawn, becauseAcinetobacter spp. are ubiquitous organisms [3, 31].     

Cultural and chemical characterization of CDC groups EO-2, M-5, and M-6, Moraxella (Moraxella) species, Oligella urethralis, Acinetobacter species, and Psychrobacter immobilis.

We determined phenotypic characteristics, cellular fatty acid composition, and isoprenoid quinone content of representative strains of CDC groups EO-2, M-5, and M-6, Moraxella (Moraxella) species, Oligella urethralis, Acinetobacter species, and Psychrobacter immobilis. All organisms contained ubiquinone with eight isoprene units as the major isoprenolog, but distinct differences were observed in fatty acid composition. Twenty-eight of the original collection of CDC group EO-2 strains were further identified as P. immobilis, EO-2, or EO-3 by distinctive cellular fatty acid profiles, cellular morphology, and pigment production. The cellular fatty acid compositions of M-5 and M-6 were similar but were clearly different from those of other organisms. The genus Acinetobacter was differentiated from other organisms in the study by small amounts of 2-hydroxydodecanoic acid (2-OH-12:0), and P. immobilis was differentiated by small amounts of decanoic acid (10:0) and a branched-chain 17-carbon acid (i-17:0). All Moraxella species were distinguished by small amounts of decanoic acid (10:0) and the absence of i-17:0. M. bovis, M. nonliquefaciens, and some strains of M. lacunata formed a single fatty acid group, while M. osloensis, M. phenylpyruvica, M. atlantae, and other strains of M. lacunata (M. lacunata II) had species-specific fatty acid profiles. O. urethralis differed from Moraxella species by the presence of large amounts (49%) of cis-vaccenic acid (18:1 omega 7c), small amounts (1%) of 3-hydroxyhexadecanoate (3-OH-16:0), and the absence of 10:0 and 3-hydroxydodecanoate (3-OH-12:0). The combined use of chemical data and a small number of conventional tests permitted rapid identification and differentiation of these organisms from each other and from related organisms.     

Plasmid DNA fingerprinting of Acinetobacter species other than Acinetobacter baumannii.

During the last years Acinetobacter species have emerged as clinically significant pathogens. Most infections are nosocomially acquired and mainly due to Acinetobacter baumannii. Little is known about the epidemiology and clinical significance of unnamed Acinetobacter species 3 (the second most often encountered member of the genus Acinetobacter) and other Acinetobacter species such as A. johnsonii, A. junii, and A. lwoffii. Seventy-five clinical isolates of Acinetobacter species other than A. baumannii (Acinetobacter species 3, n = 37; A. johnsonii, n = 20; A. junii, n = 8; A. lwoffii, n = 10) recovered from 66 patients over a period of 12 months were analyzed by plasmid DNA fingerprinting. Plasmids were found in 84.4% of Acinetobacter species 3 isolates and in all A. johnsonii, A. junii, and A. lwoffii isolates. Strains harbored up to 15 plasmids each. Almost every isolate gave a unique plasmid pattern. With one exception, identical plasmid profiles were detected only in corresponding isolates recovered from blood cultures and intravascular catheters from a given patient. Plasmid DNA fingerprinting proved to be useful for typing Acinetobacter species other than A. baumannii. There was no evidence of patient-to-patient transmission or hospital outbreaks due to these species. This finding is in contrast to the results obtained in studies of the hospital epidemiology of A. baumannii.     

Food as a source of Klebsiella species for colonisation and infection of intensive care patients.

Food prepared for intensive care patients was frequently contaminated with Klebsiella species. Sixty-eight per cent of nasogastric feeds were contaminated with up to 10(4) klebsiellae per ml. Hospital kitchens were the source of contamination. Three patients ingested klebsiellae and subsequently excreted the same serotype in their faeces. Over a four-week period there was a correlation between kitchen, food, faecal, and clinical serotypes of klebsiellae. Serotypes ingested by intensive care patients occurred more frequently in clinical isolates from intensive care patients than from other hospital patients. Patients often acquired a food strain that had been ingested by another patient on the same ward.     

Genotypic and phenotypic characterization of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex with the proposal of Acinetobacter pittii sp. nov. (formerly Acinetobacter genomic species 3) and Acinetobacter nosocomialis sp. nov. (formerly Acinetobacter genomic species 13TU)

Acinetobacter genomic species (gen. sp.) 3 and gen. sp. 13TU are increasingly recognized as clinically important taxa within the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex. To define the taxonomic position of these genomic species, we investigated 80 strains representing the known diversity of the ACB complex. All strains were characterized by AFLP analysis, amplified rDNA restriction analysis and nutritional or physiological testing, while selected strains were studied by 16S rRNA and rpoB gene sequence analysis, multilocus sequence analysis and whole-genome comparison. Results supported the genomic distinctness and monophyly of the individual species of the ACB complex. Despite the high phenotypic similarity among these species, some degree of differentiation between them could be made on the basis of growth at different temperatures and of assimilation of malonate, l-tartrate levulinate or citraconate. Considering the medical relevance of gen. sp. 3 and gen. sp. 13TU, we propose the formal names Acinetobacter pittii sp. nov. and Acinetobacter nosocomialis sp. nov. for these taxa, respectively. The type strain of A. pittii sp. nov. is LMG 1035^T (=CIP 70.29^T) and that of A. nosocomialis sp. nov. is LMG 10619^T (=CCM 7791^T).     

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.     

In-hospital source of airborne Penicillium species spores.

Between 16 July and 1 October 1984, prospectively monitored corridor air samples from a bone marrow transplant station revealed a marked increase in airborne thermotolerant Penicillium spores. Simultaneous cultures of outside air showed lower spore counts, which were unchanged before, during, and after the corridor outburst, establishing that the source was within the hospital. Although the corridor was equipped with recirculating high-efficiency particulate air filtration units which provided 16 air changes per h, the mean corridor air count rose to 64.4 thermotolerant Penicillium CFU/m3 during the outburst period. The in-hospital source was ultimately traced to rotting cabinet wood enclosing a sink with leaking pipes in the medication room. It produced approximately 5.5 X 10(5) thermotolerant Penicillium CFU/h. In a patient room supplied by corridor air, an in-room recirculating high-efficiency particulate air filter reduced the mean thermotolerant Penicillium count to 2.2 CFU/m3. No patient illness or colonization occurred as a result of this event, although the cabinet wood, after sterilization, was shown to sustain abundant growth of Aspergillus fumigatus and Aspergillus flavus. Wet organic substrates should be avoided in hospital areas with immunosuppressed patients.     

Evaluation of purified UspA from Moraxella catarrhalis as a vaccine in a murine model after active immunization.

Moraxella catarrhalis causes otitis media, laryngitis, and respiratory infections in humans. A high-molecular-weight outer membrane protein from this bacterium named ubiquitous surface protein A (UspA) is present on all isolates. A monoclonal antibody (MAb) to UspA that recognizes a conserved epitope of this protein has been shown to promote pulmonary clearance of bacteria in passively immunized mice. In the present study, M. catarrhalis heterologous isolates were screened by dot blot with a panel of four additional MAbs specific for surface-exposed epitopes of UspA from M. catarrhalis isolate 035E. Three of the MAbs were specific for 035E, and the fourth reacted with 17 (74%) of the 23 isolates tested. Thus, UspA contains highly conserved, semiconserved, and variable surface-exposed epitopes. The UspA was purified from the 035E isolate by ion-exchange and size-exclusion chromatography, formulated with the adjuvant QS-21, and used to immunize BALB/c mice. Upon pulmonary challenge with either 035E or the heterologous isolate TTA24, significantly fewer bacteria were recovered from the lungs of immunized mice 6 h postchallenge than from control mice. The immune sera from mice or guinea pigs contained high titers of antibodies to the homologous isolate and heterologous isolates in a whole-bacterial-cell enzyme-linked immunosorbent assay. Sera against UspA, whether prepared in mice or guinea pigs, had complement-dependent bactericidal activity toward homologous and 11 heterologous M. catarrhalis isolates. These results indicate that the conserved epitopes of the UspA are highly immunogenic and elicit broadly reactive and biologically functional antibodies. UspA may offer protection against M. catarrhalis infections and is being further evaluated as a vaccine candidate.     

Identification of Acinetobacter genomic species by amplified ribosomal DNA restriction analysis.

A total of 53 field and reference strains, including the type strains of the seven named species (nomenspecies) and belonging to the 18 described genomic species (DNA groups) of the genus Acinetobacter, were studied by amplified ribosomal DNA restriction analysis (ARDRA). Restriction analysis with the enzymes AluI, CfoI, MboI, RsaI, and MspI of the enzymatically amplified 16S rRNA genes allowed us to identify all species except the genomic species 4 (Acinetobacter haemolyticus) and 7 (A. johnsonii), 5 (A. junii) and 17, and 10 and 11, which clustered pairwise in three respective groups. Further analysis with the enzyme HaeIII, HinfI, NciI, ScrFI, or TaqI did not allow us to differentiate the species within these three clusters. However, use of a few additional simple phenotypic tests (hemolysis, growth at 37 degrees C, production of acid from glucose, and gelatin hydrolysis) can be used to differentiate between the species within these clusters. ARDRA proved to be a rapid and reliable method for the identification of most of the Acinetobacter genomic species, including the closely related DNA groups 1 (A. calcoaceticus), 2 (A. baumannii), 3, and 13. The results of this study suggest that ARDRA can be used for the identification of Acinetobacter species and as such may help to elucidate the ecology and clinical significance of the different species of this genus. Since ARDRA uses universal 16S rRNA gene primers, it is expected to be applicable to the identification of most bacterial species. Furthermore, ARDRA is less prone to contamination problems than PCR for detection, since the use of cultured organisms results in a large initial quantity of target DNA.     

Acinetobacter baylyi as a pathogen for opportunistic infection

There are no previous reports of human infection due to Acinetobacter baylyi. In this study, we report on six patients with bacteremia due to A. baylyi, based on analysis of the 16S-23S rRNA intergenic spacer and the 16S rRNA gene. All six patients had multiple underlying diseases. The infection was nosocomially acquired in five patients. The six clinical isolates had similar ribopatterns, suggesting a clonal relationship. Compared to the reference strain, the clinical isolates were more resistant to antimicrobial agents, especially beta-lactam antibiotics. In three of the isolates, they may have undetermined plasmid mediated class C type beta-lactamases because of the positive results in a double-disk synergy test using 3-aminophenylboronic acid. Two of the clinical isolates retained a level of natural transformability similar to that of the reference strain. None of the patients died, although only three of them received appropriate antimicrobial therapy. This study demonstrates that A. baylyi is a potential human pathogen that can cause nosocomial infection in immunocompromised patients.     

Ubiquitous Acinetobacter species as beneficial commensals but gradually being emboldened with antibiotic resistance genes

Acinetobacter spp. are ubiquitous obligate aerobic bacteria which occur mostly as commensals on the skin, and in soil, water and plants' rhizosphere. Though the species in this genus have been implicated as aetiologies in some nosocomial infections, their versatility covers biodegradation or dissolution leading to bioremediation; catalysis leading to synthesis of high molecular weight, life sustaining polymers; and as growth enhancers in agriculture. The challenge of antibiotic resistance and their mediatory genes is a cause for concern but should not deter the beneficial application of the bacteria especially in the synthesis of novel compounds that would be of relevance in overcoming some global ecological challenges. This review addresses important beneficial attributes of Acinetobacter species as well as gives some insight into emerging trends in their resistance to antibiotics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Desmoplastic breast carcinoma as a source of human myofibroblasts.

Primary cell cultures of human myofibroblasts can be obtained from desmoplastic breast carcinoma, a tissue rich in these cells. Explants of infiltrating breast carcinoma (scirrhous type) give rise to outgrowths of cells which are predominantly (greater than 90%) myofibroblasts. These cells retain their identifying morphologic characteristics in cell culture by both ultrastructural and immunocytochemical criteria: the presence of elongated cells with longitudinally oriented thin filaments peripherally condensed to form dense zones and abundant rough endoplasmic reticulum; cytoplasmic immunoreactivity for myosin and Type V collagen. These myofibroblasts continue to divide and retain their morphologic characteristics for at least 14 days. These findings allow for further in vitro studies concerning both the role and regulation of the myofibroblast in the desmoplastic response.     

The transplanted kidney as a source of cytomegalovirus infection.

To determine the incidence of cytomegalovirus infection in renal-transplant recipients we followed 32 prospectively for six months after operation. As judged by serologic change and virus isolation the infection rate for the entire group was 66 per cent (21 of 32 patients) - 59 per cent (13 of 22) for seronegative patients and 80 per cent (eight of 10) for seropositive patients. Of 10 seronegative patients who received kidneys from seronegative donors, only three became infected. However, of 12 seronegative patients who received kidneys from seropositive donors, 10 became infected. Thus, there was a significant correlation between development of infection and seropositivity of the donor (P = 0.03), particularly when the recipient was seronegative (P = 0.02). Five possible and four definite recognizable clinical illnesses were associated with cytomegalovirus infection; all except two were in initially seronegative subjects who received kidneys from seropositive donors. Primary infection and disease in nonimmune recipients may be caused by cytomegalovirus transmitted by the kidneys of latently infected seropositive donors.     

Molecular epidemiology of clinical Acinetobacter baumannii and Acinetobacter genomic species 13TU isolates using a multilocus sequencing typing scheme

To further expand the limited multilocus sequence typing (MLST) database for Acinetobacter baumannii , 53 clinical isolates from various outbreaks in Europe and the USA, collected between 1991 and 2004, plus the A. baumannii reference strain ATCC 19606^T and 20 clinical Acinetobacter genomic species 13TU isolates from the same period, were analyzed using a new MLST scheme based on fragments of the gltA , gyrB , gdhB , recA , cpn60 , gpi and rpoD genes. Data were compared with typing results generated using pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD)-PCR. In total, 50 sequence types (STs) were distinguished among the A. baumannii isolates investigated, and the MLST data were in high concordance with the PFGE and RAPD-PCR results. Only five clonal complexes were identified by eBURST analysis, including the 21 STs listed in a previous study, suggesting high diversity among the A. baumannii isolates. With one exception, there was no relatedness among isolates from outbreaks in different countries (Europe) or regions (USA). No intercontinental spread was revealed. Acinetobacter genomic species 13TU isolates could also be analyzed using the A. baumannii MLST scheme (18 different STs) and could be distinguished from A. baumannii isolates according to characteristic sequences. It was concluded that the MLST scheme provides a high level of resolution and is a promising tool for studying the epidemiology of A. baumannii and Acinetobacter genomic species 13TU.     

Skin temperature over an artificial heat source implanted in man.

The medical application of infrared thermography makes use of the skin temperature as an indication of an underlying pathological process. In order to study the relation between the heat production from a source in living tissue and the overlying skin temperature, artificial heat sources were implanted subcutaneously in human volunteers. The experimental results show that a detectable surface temperature increase over the heat sources presupposes high power output or superficial implantation. The effect of forced convective heat loss from the skin surface and lowered ambient temperature was studied. Forced convection markedly decreased the temperature contrast. An implicit conclusion from experimental and theoretical work is that a localized 'hot spot' can only exceptionally be attributed to metabolic heat production conducted to the skin surface from a buried pathological process. The thermal pattern over a breast tumour, a septic or aseptic inflammation or a tissue injury mainly reflects the vascular reaction.