Alcaligenes xylosoxidans endocarditis of a prosthetic valve and pacemaker in a 62-year-old woman.

The bacterium Alcaligenes xylosoxidans is known to cause several nosocomial infections; however, it rarely causes endocarditis, which has a very high mortality rate. Early isolation of the infection source and prompt identification of the patient's antibiotic sensitivities are paramount if the infection is to be treated adequately. We present what is apparently only the second documented case of the successful eradication of bioprosthetic valve endocarditis that was caused by pacemaker lead infection with Alcaligenes xylosoxidans. A 62-year-old woman with multiple comorbidities presented with endocarditis of a recently placed bioprosthetic aortic valve. The infection was secondary to pacemaker lead infection. She underwent antibiotic therapy, but an unusual pattern of antibiotic resistance developed. Despite initially adequate therapy, the infection recurred because of virulence induced by antibiotic resistance. Emergent, high-risk surgical treatment involved excising the infected valve and removing the source of the infection (the pacemaker leads). The patient eventually recovered after prolonged antibiotic therapy and close vigilance for recurrent infection. In addition to the patient's case, we discuss the features of this bacteremia and the challenges in its diagnosis.

Ochrobactrum anthropi bacteremia.

Ochrobactrum Anthropi (O. anthropi ), formerly known as Achromobacter CDC group Vd, is a gram-negative bacillus that is aerobic, oxidase producing, and nonlactose fermenting. This organism has been found in environmental and hospital water sources and has pathogenic potential in humans. Most reports in the literature of O. anthropi bacteremia are associated with intravenous line infections. We describe a case of bacteremia with O. anthropi in a 33-month-old boy with acute osteomyelitis. O. anthropi bacteremia also has been reported in immunocompromised hosts. Rarely, O. anthropi has been a cause of soft tissue or bone infection.

[Case report: subcutaneous abscess and thoracic empyema caused by Alcaligenes xylosoxidans].

Alcaligenes xylosoxidans is a glucose-nonfermentative gram-negative rod which usually exists in the environment. This organism while causing pneumonia, sepsis, meningitis and urinary tract infection in the compromised host, rarely causes thoracic empyema. We report a case of thoracic empyema and subcutaneous abscess due to A. xylosoxidans. A 74-year-old male, who had undergone right total pneumonectomy for chronic necrotizing pulmonary aspergillosis a year ago, was admitted to our hospital because of fever. CT scans of the chest revealed a subcutaneous abscess and empyema. Empyema and subcutaneous pus were aspirated. Culture of materials produced A. xylosoxidans. There was no significant change on symptoms and examinations despite therapy with PIPC 4 g/day and thoracic drainage. Finally, surgical treatment was required and the patient was cured.

Effects of atrazine on Ochrobactrum anthropi membrane fatty acids.

Ochrobactrum anthropi is a gram-negative bacillus recognized as a human opportunist pathogen isolated in clinical specimens and not of clinical significance. We report a new aspect of this bacterium, that it has been isolated from activated sludge. In fact, it is able to grow on atrazine (2-chloro-4-ethylamino-6-isopropyl-amine-s-triazine) by utilizing it as the only source of carbon. Our results show that atrazine (0.03 g/liter) causes a dramatical increase in the degree of saturation of membrane fatty acids. Analysis and identification of bacterial fatty acids were performed by gas chromatography and gas chromatography-mass spectrometry techniques.

Ochrobactrum anthropi meningitis in pediatric pericardial allograft transplant recipients.

An epidemiologic investigation was done after 3 patients contracted Ochrobactrum anthropi meningitis at one hospital in October 1994. Neurosurgical patients with pericardial tissue implants were at greater risk of infection than other neurosurgical patients (3/14 vs. 0/566; P<.001). Cultures of implants removed from 2 case-patients, an implant at implantation, a nonimplanted pericardial tissue, and an unwrapped but unopened bottle of Hank's balanced salt solution (HBSS) grew O. anthropi. Patient and tissue isolates had identical genotypes; the isolate from the HBSS bottle had a unique genotype. Culture samples from an unopened HBSS bottle and from pericardial tissue grew Pseudomonas stutzeri of the same genotype; however, no P. stutzeri infections were detected. The investigation documented intrinsic P. stutzeri contamination of HBSS. O. anthropi contamination of tissues occurred during processing, possibly due to extrinsic contamination of HBSS. Active surveillance is needed to detect infection in patients receiving transplanted tissues, and rigorous infection control practice are necessary during tissue harvesting and processing to ensure sterility.

Plasmid DNA of virulent Alcaligenes faecalis.

Alcaligenes faecalis strains originating from chickens and from epizootics of coryza in turkeys were screened for antibiotic susceptibility and for the presence of plasmid DNA. Seven of 35 strains contained plasmid DNA ranging in size from 10.5 to approximately 32 megadaltons. All of the strains isolated from turkeys were virulent in turkey poults, but only the plasmid-containing strains were resistant to sulfonamides and streptomycin. Four of the plasmid-containing strains were also resistant to tetracycline. Five different plasmids representing at least 2 different incompatibility groups were identified in the 7 plasmid-bearing A faecalis strain.

Efficacy of a commercial turkey coryza vaccine (Art-Vax) in turkey poults.

Four laboratory experiments were designed to study the efficacy of the only available commercial vaccine for turkey coryza, Art-Vax. Poults were vaccinated either once or twice at different ages and challenged with pathogenic Alcaligenes faecalis. In another study, commercial turkeys vaccinated at 1 and 12 days of age on a commercial farm were brought to the laboratory for challenge with pathogenic A. faecalis. Both the laboratory- and field-vaccinated poults were given the manufacturer's recommended dosage of the vaccine strain. Regardless of the vaccine schedule or source of poults, the vaccine was not effective in protecting challenged turkeys from infection. Furthermore, the vaccine was not effective in protecting poults less than 3 weeks of age from disease, but it was effective in protecting poults more than 3 weeks of age from disease. These results indicate that although vaccinated turkeys older than 3 weeks of age were not susceptible to disease, they were susceptible to infection and could act as carriers of field strains of A. faecalis, thus perpetuating the risk of infection to flocks subsequently raised in the same buildings.

Further characterization of the agent causing coryza in turkeys.

A total of 128 isolates of Alcaligenes faecalis, from the respiratory tract of turkeys and chickens, were identified and divided into two types designated type I and type II. Type I isolates were pathogenic in poults, hemagglutinated guinea pig red blood cells (RBCs), and did not grow on minimal essential medium (MEM) agar, and most did not grow in 6.5% NaCl broth. Type II isolates were nonpathogenic and nonhemagglutinating and grew on MEM agar, and most grew in 6.5% NaCl broth. Hemagglutination of guinea pig RBCs was a reliable characteristic for distinguishing type I from type II isolates, and it correlated with pathogenicity. In serological studies using 62 type I and 21 type II isolates, cross-reactions were observed when type I but not type II antigens were used to test antisera in the microagglutination test. Eleven bacterial isolates, different from type I and type II isolates, were urease-positive. Although frequently isolated from turkeys with coryza, these isolates were nonpathogenic and were always found in association with type I A. faecalis. Urease-positive isolates and type I and type II A. faecalis isolates were stable following 50 in vitro passages. Bordetella avium sp. nov. (the nomenclature suggested in Europe for A. faecalis) was pathogenic in poults. The colonial morphology, biochemical characteristics, and hemagglutinating activity of B. avium sp. nov. were the same as those of type I A. faecalis isolates. Based on the results of these studies, it was concluded that type I A. faecalis is the etiologic agent of turkey coryza.

An Alcaligenes faecalis isolate from turkeys: pathogenicity in selected avian and mammalian species.

An Alcaligenes faecalis isolate of known pathogenicity for turkeys was examined for adherence and cytotoxicity in tracheal organ cultures of turkeys, chickens, Japanese quail, guinea pigs, hamsters, and mice, and for colonization and pathogenicity in these 6 species. Adherence and colonization were detected by fluorescent antibody staining. Infected and noninfected tracheal rings were examined by phase-contrast microscopy for cytotoxicity (ciliostasis, blebing of the cell membrane, and sloughing of the ciliated epithelium). Alcaligenes faecalis adhered to the tracheal rings of all species examined. Cytotoxicity was apparent in the tracheal rings of turkeys, quail, and chickens. Cytotoxicity was not detected in tracheal rings from the mammalian species. Alcaligenes faecalis colonization of turbinates and tracheas of intact turkeys and quail was detected. Clinical signs of alcaligenes rhinotracheitis were observed and histopathologic characteristics of the disease were detected. Chickens, guinea pigs, hamsters, and mice were refractory to infection with this isolate of A faecalis.

Evidence for adherence-dependent cytotoxicity of Alcaligenes faecalis in turkey tracheal organ cultures.

A virulent isolate of Alcaligenes faecalis was examined in turkey tracheal organ cultures (TTOC) for adherence using immunofluorescent staining and for cytotoxicity using light microscopic observation. Treatment of the bacterial culture with trypsin, antiserum specific for A. faecalis, and N-acetylneuraminic acid inhibited the ability of the organism to adhere to TTOC. Treatment of the bacterium with D-galactose partly decreased adherence of the bacterium. Those treatments that inhibited the adherence of A. faecalis also inhibited the cytolytic activity in TTOC. Treatment of the bacterial culture with D-galactose only partly decreased the cytolytic activity. These data indicate that adherence of the organism to TTOC is necessary for the cytolytic activity characteristic of A. faecalis isolates capable of causing alcaligenes rhinotracheitis in turkeys.

Evidence for plasmid DNA in Alcaligenes faecalis.

A 10.6 megadalton plasmid was isolated from a virulent strain (NC-D) of Alcaligenes faecalis. Virulence and antibiotic sensitivity of this strain were compared with those characteristics of a mutant plasmid-free derivative, strain NC-D1. Strain NC-D1 was avirulent and lacked the streptomycin and sulfonamide resistances of the parent strain.

Pathogenicity of various isolates of Alcaligenes faecalis for broilers.

Day-old broilers or specific-pathogen-free chickens were inoculated intranasally with approximately 1 X 10(8) organisms of eight different field isolates of Alcaligenes faecalis. Major differences in the pathogenicity of isolates and their ability to colonize the trachea were found. Only two isolates (Wilson and Lockamy) produced mild clinical signs of respiratory disease ("snicking," dyspnea). The same two also colonized the respiratory tract, especially the trachea, in large numbers; they persisted for 31 days. Of the remaining six isolates, five were also able to colonize the respiratory tract but did so to a lesser degree and less persistently, without causing clinical signs. Only one isolate (CS) was incapable of becoming established in the respiratory tract of chicks after intranasal inoculation.

Observations on the pathogenicity of Alcaligenes faecalis in chickens.

A series of trials was conducted in which specific-pathogen-free (SPF) leghorn chicks were exposed to various isolates of Alcaligenes faecalis. Chicks were inoculated with A. faecalis alone or in combination with Newcastle disease/infectious bronchitis (Nc/Br) vaccine, laryngotracheitis vaccine, infectious bursal disease virus, or Mycoplasma gallisepticum. The response was evaluated by morbidity, mortality, airsacculitis, reisolation of A. faecalis, and histopathological lesions of tracheas. Although A. faecalis was recovered up to 42 days postinoculation in some cases, no clinical signs were directly attributed to simple A. faecalis infection. None of the other agents significantly increased the severity of A. faecalis signs or lesions, except that A. faecalis-infected chicks that were given Nc/Br vaccine had prolonged microscopic tracheal lesions. In another trial, the effects of A. faecalis in young SPF leghorns, non-SPF broilers, and turkeys were compared. Broiler-type chicks were more susceptible than leghorns and less susceptible than poults. Consequently, the use of leghorns as a model for studying this infection is questioned.

Susceptibility of turkey poults from vaccinated and unvaccinated hens to alcaligenes rhinotracheitis (turkey coryza).

One specific-pathogen-free breeder flock of Beltsville small white turkeys was given two doses of oil-emulsion-adjuvanted Alcaligenes faecalis bacterin 3 months apart, and another flock was left unvaccinated. Progeny from each flock from eggs laid after both first and second vaccination were exposed to the homologous strain (838) of A. faecalis at 1 day of age either experimentally (10(7) colony-forming units intranasally) or naturally (continuous contact with an infected poult) and monitored for 2, 4, or 6 weeks. Progeny from vaccinated hens had substantial resistance to alcaligenes rhinotracheitis compared with progeny from unvaccinated hens; resistance was greatest in progeny from twice-vaccinated hens. Poults from vaccinated hens had improved livability and growth, delayed onset of infection and clinical signs, and a less severe disease process. The results of this study indicate that breeder hen vaccination could be a useful method for providing poults with early protection against alcaligenes rhinotracheitis.

Cytotoxic activity of pathogenic Alcaligenes faecalis in turkey tracheal organ cultures.

Turkey tracheal organ cultures were used to study the virulence of Alcaligenes faecalis isolants that have been shown to be pathogenic for turkey poults. Viable infected and noninfected tracheal rings were examined by phase-contrast microscopy, and fixed stained sections were examined by light microscopy. Alcaligenes faecalis at concentrations of 10(8) and 10(9) colony-forming units/ml caused ciliostasis, hydropic degeneration (characterized by blebbing of the plasma membrane, cellular swelling, and cytoplasmic vacuolation), and eventual sloughing of the ciliated epithelium. Only ciliated epithelial cells appeared affected. For comparison, other bacterial isolants not pathogenic for turkeys were tried in this system. These bacterial isolants included 3 isolants of A faecalis from human beings and isolants of Klebsiella pneumoniae, Escherichia coli, and A faecalis from turkeys. Inoculation of each of these bacterial cultures onto tracheal organ cultures failed to produce the lesions described.