The bacterial colonisation of silicone oil used in the management of wounds of the hands--a source of nosocomial infection?

For 30 years, silicone oil has been used for the management and rehabilitation of the injured hand. Its benefits accrue from its providing a non-irritant, bland, air-free medium in which the hand can undergo early movement, which prevents drying out of the tissues and helps in the separation of necrotic and infected tissue. It has been reported, however, that the silicone oil might act as a reservoir for nosocomial infection after two patients developed epidemic methicillin-resistant Staphylococcus aureus (EMRSA) infections. Since no firm guidelines exist with regard to open and/or infected wounds and the continued use of the same oil, a prospective study was set up to study the bacterial colonisation of the silicone oil. Thirty-five consecutive patients were entered into the study. The oil for each patient was changed each week but if any wound became clinically infected the oil was changed earlier. Treatment was continued until the wound was healed or until the treatment was stopped by the referring doctor. Bacteriology swabs taken from the wound and the oil before each treatment and from the oil after each treatment were analysed for bacterial colonisation. The results indicated that while bacteria were transferred into the oil from the wound, the inoculum was small and had no effect on wound healing. There was no evidence that wounds were being re-infected from the oil. The conclusion was that silicone oil remains a safe medium in which to exercise injured hands.

Validation of a Trauma Questionnaire in veteran women.

The Trauma Questionnaire (TQ) assesses a woman's history of childhood and adult sexual trauma, sexual harassment, and domestic violence. The TQ is used widely at Veterans Affairs Medical Centers, but its validity has not been thoroughly examined. In a prospective study of 127 women, we found the TQ to have good to excellent agreement with a semistructured clinician interview and good sensitivity and specificity. The TQ can be used as a valid alternative to the clinician interview in the initial elicitation of trauma history among women veterans in the primary care setting.

Effects of flunixin and flunixin plus prednisone on the gastrointestinal tract of dogs.

Flunixin meglumine has been reported to induce gastrointestinal lesions in dogs when administered at therapeutic dosages. We administered flunixin meglumine to dogs daily for 10 days to assess the effect of this drug on the gastrointestinal tract. We also evaluated the possibility of corticosteroid potentiation of gastrointestinal toxicosis by concurrent administration of prednisone to 1 group of dogs. Dogs were monitored for gastrointestinal toxicosis by means of serial endoscopic evaluation, measurement of fecal occult blood, PCV, and total solid concentration, and by physical examination. There were 3 treatment groups of 5 dogs each. Group-1 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses IM; group-2 dogs were given 4.4 mg of flunixin meglumine/kg daily, in 2 divided doses IM; and group-3 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses IM plus 1.1 mg of prednisone/kg/d orally, in 2 divided doses. A fourth group of 5 dogs served as a control group. Endoscopically visible gastric mucosal lesions developed in all treated dogs within 4 days of initiating treatment. Lesions first developed in the gastric pylorus and antrum and lesions at these sites were more severe than those observed elsewhere. Dogs treated with flunixin meglumine plus prednisone developed the earliest and most severe lesions; lesion scores in group-2 dogs were higher than those in group-1 dogs. All dogs treated had occult blood in their feces by day 5 and its presence appeared to correlate more closely with endoscopic findings than did physical examination findings or changes in values for PCV or total solids.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Actinomyces pyogenes and gram-negative anaerobic bacteria on the development of bovine pyometra.

Fifteen lactating Holstein cows were used in a trial designed to evaluate the effectiveness of intrauterine inoculation (challenge) of Actinomyces pyogenes (A) alone or in combination with Fusobacterium necrophorum (F) and Bacteroides melaninogenicus (B) to induce pyometra. Cows were assigned to one of five groups: A (n = 3), AB (n = 3), AF (n = 3), ABF (n = 3) or C (control, broth medium alone; n = 3). All cows exhibited estrus 12 or 13 d prior to challenge (Day 0=first day of challenge). During the prechallenge period, the reproductive tract of each cow was palpated per rectum and uterine fluid aspirates for culture and uterine biopsies were also obtained. All cows received an intravenous injection of 5,000 IU of human chorionic gonadotropin (hCG; Day 5) and an intrauterine infusion of 40 ml of 0.7% iodine solution (Day 1). Cows were then inoculated on Days 0, 1 and 2 of the experiment. Sequential palpations of the reproductive tracts, samples of uterine fluid for culture and uterine biopsies were performed for a total of 30 d after the first inoculation. A cow was diagnosed as having pyometra when purulent uterine fluid and a corpus luteum were detected by palpation per rectum. The number of cows that developed pyometra in Group A was 2 of 3, in Group AB 3 of 3, in Group AF 3 of 3, in Group ABF 3 of 3 and in Group C 0 of 3. Cows with pyometra did not exhibit estrus. In 7 of 11 cows, pyometra persisted for more than 21 d. In cows that developed pyometra, the same species of bacteria infused into the uterus were usually recovered one or more times during the postchallenge period. When clinical pyometra was diagnosed, histologic endometritis was invariably present. Histologic endometritis and concurrent isolation of A . pyogenes alone or A . pyogenes with gram-negative anaerobic bacteria occurred in 91.7% of samples during the postchallenge period. Regardless of bacterial treatment, gram-negative anaerobic bacteria were frequently isolated with A . pyogenes during this period.

Vaccination-related anthrax in three llamas.

Two llama calves died 3 days after inoculation with anthrax vaccine. Concurrent administration of ivermectin and other biologics may have enhanced the infectivity of the Sterne strain vaccine of Bacillus anthracis. This experience suggests that the Sterne strain of anthrax vaccine can induce fatal disease when given to young llamas and should be used only with extreme care and in face of strong "at risk" situations.

Isolation of a retrovirus from the American bison and its relation to bovine retroviruses.

Tissue samples were removed at necropsy from five American bison (Bison bison) with clinical signs of a disease resembling malignant catarrhal fever (MCF). Using cell-associated virus techniques, attempts were made to isolate viruses from these tissues by culturing them directly or by co-culture with bovine fetal cells. Among the viruses isolated was one which was syncytiogenic and multiplied in bovine fetal spleen cells and remained highly cell-associated. The presence of reverse transcriptase activity indicated that it was a retrovirus. Also, it had antigenic cross activity with bovine syncytial virus, but not with bovine leukemia or bovine maedi-like retroviruses. We do not attribute a direct causative role of this retrovirus to MCF, but indirect relationships are possible.

Use of radiotherapy for the treatment of intranasal tumors in cats: six cases (1980-1985).

Six cats with intranasal neoplasia treated with radiotherapy were evaluated. The mean survival time from the initiation of radiotherapy was 19 months, with 2 cats still known to be alive. Two cats died for reasons unrelated to the primary tumor. One cat had no clinical evidence of nasal tumor 41 months after treatment, but was lost to further follow-up evaluation.

Ameloblastic odontoma in a dog.

An ameloblastic odontoma in the right maxilla of a 10-week-old, female Springer Spaniel was treated by extensive curettage. Twelve months after surgery there was no recurrence of the neoplasm.

Oxytetracycline-associated nephrotoxicosis in feedlot calves.

Renal nephrosis and increased mortality were investigated in feedlot calves that had received excessive doses of oxytetracycline for the treatment of bronchopneumonia. Histopathologic findings included moderate to severe, cortical tubular nephrosis, and suppurative bronchopneumonia. Results of serum and peritoneal fluid analysis were consistent with severe renal disease. Renal toxicosis from the administration of excessive oxytetracycline should be considered a possible side effect in stressed calves with concurrent respiratory disease.

Accidental monensin sodium intoxication of feedlot cattle.

Of 1,994 yearling and 2-year-old cattle in a winter feeding program, 117 died within 42 days of being fed toxic amounts of monensin sodium in a liquid protein supplement. Death losses commenced on the third day after ingestion of a toxic amount in the feed. Clinical signs in cattle that died in less than 9 days included anorexia, pica, diarrhea, depression, mild hindlimb ataxia, and dyspnea. Gross necropsy findings in cattle dying in the acute phase of the illness included hydrothorax, ascites, and pulmonary edema, as well as petechial hemorrhages, edema, and yellow streaking in skeletal and cardiac muscle. Cattle dying after 9 days had gray streaks in heart and skeletal muscle, generalized ventral edema, enlarged, firm, bluish discolored liver, and enlarged heart. Microscopic changes in cattle dying in the acute phase (less than 9 days) consisted of pulmonary edema, congestion, and hemorrhage. Cardiac and skeletal muscle had localized areas of edema, hemorrhage, and coagulative necrosis. In cattle dying after 9 days of illness, the changes included lymphocytic infiltration, sarcolemmal nuclear proliferation, and fibrosis in skeletal and cardiac muscle. Lungs contained increased alveolar macrophages and a few neutrophils. Centrilobular necrosis and mild fibrosis were found in the liver. Changes varied somewhat according to the area of heart or skeletal muscle that was affected. Active muscles, eg, those in the heart ventricles and diaphragm, were altered most severely. Intoxication appeared to be a result of sedimentation of monensin in the molasses carrier to give remarkable concentrations of the substance at the bottom of the holding tank.

Identification of carriers of Streptococcus equi in a naturally infected herd.

During an outbreak of strangles in a population of research horses, 4 mares were identified as carriers of Streptococcus equi. Three of the mares had typical signs of strangles (severe regional lymphadenitis with or without rupture of abscessed lymph nodes). The 4th mare experienced episodes of serous to mucopurulent nasal discharge, but never had more than a mild degree of lymph node enlargement. Streptococcus equi was isolated from the abscessed lymph nodes and from nasopharyngeal swab specimens from the first 3 mares from 6 to 19 weeks after rupture of involved nodes. Streptococcus equi was isolated from the nasopharynx of the 4th mare on introduction into the herd and intermittently over the ensuing 6 months. During the 7th month, mare 4 was placed in isolation, where she continued to shed S equi for 4 more months. A complete physical examination during the 10th month, including radiography of the head and thorax, did not reveal any relevant abnormalities, but a pharyngeal swab specimen was culture-positive for S equi. This isolate was used to inoculate 2 yearling colts, which developed strangles and from which S equi was reisolated. Shedding of S equi by mare 4 ceased in the 11th month, and at necropsy 2 months later, S equi was not recovered from any organ or tissue. Corticosteroid administration 3 weeks prior to necropsy had induced neither shedding of the organism nor clinical signs of strangles. The study provided clinical, epidemiologic, and bacteriologic evidence to support the existence of a carrier state following natural infection with S equi.

Experimental infections of horses with Legionella pneumophila.

Attempts to infect horses with Legionella pneumophila were undertaken to determine pathogenicity and to evaluate the possibility that horses serve as a reservoir for the organism. A previous study showed that the prevalence of antibodies to L pneumophila in the equine population exceeded 30% of over 600 sera examined. Horses were infected experimentally with the Philadelphia 1 or Bloomington 2 strain of L pneumophila IV or by aerosolization. Signs of clinical illness were restricted to a transient febrile response. A transient decrease in circulating lymphocytes occurred 2 days after inoculation. At necropsy, only moderate generalized lymphadenopathy was noted. Histologically, the lungs contained evidence of a low-grade inflammatory response characterized by focal proliferation of alveolar lining cells, with few neutrophils and eosinophils. Lymph nodes had evidence of reactive hyperplasia. The tissue response to Bloomington 2 strain was slightly more pronounced than that to Philadelphia 1. Attempts to reisolate L pneumophila from blood and nasal or pharyngeal swabs were unsuccessful. The organism was not isolated by culturing tissues obtained at necropsy, nor was it demonstrated by tissue-staining techniques. However, all horses exhibited a marked increase in agglutinating antibodies to L pneumophila serogroups (SG) 1 and 3 as early as 4 days after inoculation. The serologic response was confirmed by indirect immunofluorescence and was shown to consist predominantly of immunoglobulin M by 2-mercaptoethanol treatment. Agglutinating antibodies persisted at least 4 months after infection. On the basis of these studies, the pathogenicity of L pneumophila SG 1 and 3 for the horse appears to be low. There is no evidence to support a role for the horse in the maintenance of these organisms in nature. Horses may be exposed in the environment and maintain a relatively long-lived serologic response to L pneumophila. However, it is also possible that they become infected with other strains of L pneumophila or Legionella-like organisms more pathogenic for horses, or other non-Legionella bacteria, which elicit a cross-reacting serologic response to L pneumophila SG 1 to 4.

Chlamydia psittaci induced pneumonia in a horse.

An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in complement fixing antibody titers. Post mortem examination of one pony revealed microscopic evidence of a generalized chlamydial infection. Lesions of interstitial pneumonia and focal hepatic necrosis were observed, and Chlamydia psittaci subsequently was reisolated from the lung tissues of the pony.

Infiltrative lipoma in dogs.

Infiltrative lipomas, similar to those described in man, were diagnosed in 12 dogs of various breeds, sexes, and ages. The neoplasms were poorly delineated, soft enlargements in muscle and connective tissue that caused dysfunction because of mechanical interference or pressure pain. The neoplasms consisted of differentiated fat cells that had infiltrated between or replaced muscle, collagen fibers or both. Single or multiple recurrences followed surgical removal in four of eight dogs: no follow-up was possible in the other four.

Experimental transmission of bovine malignant catarrhal fever to a bison (Bison bison).

Malignant catarrhal fever (MCF) was transmitted to a bison (Bison bison) by intravenous inoculation of whole blood obtained from a calf showing signs of experimental MCF. Clinical signs evident on the 25th day following inoculation included depression, weakness, epiphora, serous nasal discharge, watery diarrhea and multifocal ulcerations of oral mucosa. Gross and histopathological lesions observed in the bison were similar to those in cattle with a few qualitative differences. Compared to bovine cases, MCF in bison was characterized by more severe edema, congestion, and hemorrhage and accumulation of fewer lymphoid cells in lesions.

Clinical and clinicopathologic observations in induced malignant catarrhal fever of cattle.

In an epizootic of malignant catarrhal fever in 1976/1977 in southern California, 166 cows (17%) died. Blood from one of those cows was used in transmission studies involving 8- to 14-month-old steers. In 17 (74%) of 23 inoculated steers, the disease was reproduced. The clinical signs in 8 of the diseased steers were characterized by an initially mild intestinal form of the disease, which suddenly fulminated and terminated in death within 1 to 3 days. No lesions or only mild oral or ocular lesions were noticed in this group, but in the other steers, such lesions predominated. It was concluded that a subtle form of the disease can terminate in acute fatal indigestion.

Experimental transmission of malignant catarrhal fever in cattle: gross and histopathologic changes.

Bovine malignant catarrhal fever (MCF) was serially transmitted from a spontaneous case to 19 cattle through 12 passages during a 12-month period. Seventeen of 23 cattle (74%) injected with whole blood and 2 of 5 cattle (40%) injected with blood mononuclear cells developed clinical signs of MCF after a mean incubation period of 30.2 days. A previously unreported nonsuppurative polyarthritis is described. Large numbers of lymphoid cells were found in synovial fluid and in cerebrospinal fluid. Histopathologic changes of lymphoid infiltration and proliferation, necrosis of epithelial tissues, and nonsuppurative vasculitis were found in almost all organs of the body. The possibility that MCF may be a viral-induced, cell-mediated immunopathologic disease with pansystemic lymphoreactivity and necrosis is discussed.

Cryptosporidiosis in immunodeficient Arabian foals.

Five of six immunodeficient Arabian foals that died of adenoviral infection were found to be infected with an intestinal coccidian of the genus Cryptosporidium. Various developmental stages of the organism were found in the microvillous border of the intestinal mucosa. The foals had diarrhea but it was not possible to separate the effects of the cryptosporidial infection from those of the concomitant adenoviral enteritis.

Shipping fever pneumonia in yearling feedlot cattle.

During each week of 1974, we surveyed, for illnesses and deaths, a continually changing population of yearling feedlot cattle that, for the year, totaled 407,000 animals. About 5.1% of the cattle sickened and, of these, 18.9% died. From the 3,943 fatalities, 1,988 necropsies were made. About 75% of the clinical diagnoses and 64% of the necropsy diagnoses were respiratory tract diseases; of the fatalities from respiratory tract diseases, 75% were attributed to shipping fever pneumonia. Nearly 72% of fatal cases of shipping fever pneumonia occurred during the first 45 days on feed. In the lungs of most cattle with shipping fever pneumonia, bronchiolitis, fibrinous exudate, colonies of microorganisms, lymphatic clots, intravascular clots, thromboses, and foci of necrosis were found. Pasteurella spp, Mycoplasma spp, and infectious bovine rhinotracheitis virus were isolated from pneumonic tissues. It was hypothesized that pathogenic Pasteurella spp and other microorganisms in nasal secretions transfer from the nasopharynx into the lungs by draining along the tracheal floor into ventral bronchi, bronchioles, and alveoli, and that pasteurella endotoxin, formed in infected lobules, thromboses and occludes lymphatics, capillaries, and veins and thereby causes ischemic necrosis.