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Biomedical subjects

A Back

Publications and source records attributed to A Back.

27 records · Page 2Linked to original sources
PubMed1977

Patterns of sexually transmitted enteric diseases in a city.

In the past three years cases of shigellosis, amoebiasis, and viral hepatitis A and B have increased fourfold to tenfold in San Francisco. These diseases were most common in people who had adopted "alternative life-styles", especially in young men, In many cases there was a history of frequent orogenital and oral-anal sexual contact between men with no common source. Despite energetic public-health measures and intensive efforts by physicians treating these cases, the increase has not yet been brought under control. Other cities may experience similar difficulties with sexual transmission of enteric diseases.20

Adult↗
PubMedDate not supplied

Treatment of chancroid with erythromycin.

Chancroid is a sexually transmitted disease that is not often recognized in the United States. It has traditionally been treated with sulfonamides and/or tetracyclines. Recently, 14 active-duty U. S. Army personnel who acquired chancroid in the Far East were seen at the Madigan Army Medical Center, Tacoma, Wash. All of the organisms were isolated from clinical material on solid media without the use of a blood-clot tube. Because of dissatisfaction with conventional treatment and the demonstration of in vitro sensitivity of the organism to erythromycin, seven of the last eight patients were treated with erythromycin. All patients treated with erythromycin had rapid and favorable responses and none suffered recurrences. The results of this study led to three conclusions: chancroid is a relatively common disease in the Far East, the causative organism can be isolated by most clinical microbiology laboratories with proper technique, and erythromycin is an effective drug in the treatment of chancroid.

Adult↗
PubMedDate not supplied

Development, characterization, and preliminary evaluation of a temperature-sensitive mutant of Ornithobacterium rhinotracheale for potential use as a live vaccine in turkeys.

A temperature-sensitive (Ts) mutant strain of Ornithobacterium rhinotracheale (ORT) was developed after exposure of the wild-type organism to N-methyl-N'-nitro-N-nitrosoguanidine. The Ts mutant strain grew at 31 C but had its growth inhibited at 41 C unlike wild-type parent strain. The Ts mutant and parent strains were characterized. Morphologic and biochemical properties of wild-type and mutant strains did not show any differences. The strains were also characterized by polymerase chain reaction (PCR)-based fingerprinting methods. Results showed similar patterns in repetitive sequences by repetitive PCR (enterobacterial repetitive intergenic consensus, highly conserved repeated DNA elements present in Streptococcus pneumoniae (BOX), repetitive extragenic palindromic, and Salmonella enteritidis repetitive element primers); however, random amplified polymorphic DNA fingerprinting was able to differentiate mutant and parent strains showing a unique pattern for each of the ORT strains. The rationale for the use of a Ts strain as a vaccine is based on the ability of the mutant to colonize the upper respiratory tract but not the lower respiratory tract and systemic system of the birds, where the wild-type strain causes severe lesions. In a preliminary evaluation, Ts strain of ORT was recovered from tracheas and choanae of Ts-treated turkeys for 13 days postadministration of the strain either in drinking water or by oculonasal instillation. Humoral immune response was detected in Ts-vaccinated but not in control group birds after 3 wk postadministration. Results suggest that Ts strain of ORT has promising potential use as a live vaccine for ORT.

Animals↗
PubMedDate not supplied

Susceptibility of broiler chicks to infection by avian pneumovirus of turkey origin.

In this paper we present the results of studies on the infectivity of an isolate of avian pneumovirus (APV) from turkeys to broiler chickens. Two-week-old broiler chicks free of antibodies to APV were exposed either by oculonasal or oral route with a cell cultured APV of turkey origin. Chickens from both APV-inoculated groups exhibited clinical signs that included coughing, sneezing, nasal discharge, and watery eyes during 2-8 days postinoculation. Tissue samples from birds in the APV-inoculated group were positive for APV by polymerase chain reaction (PCR) up to 9 days postinoculation. Samples of blood from both oculonasally and orally infected chickens were positive for APV. Intestinal samples from chickens infected with APV orally were positive for the presence of APV on PCR up to 9 days postinoculation. APV was reisolated from samples taken from chickens in both groups inoculated orally and oculonasally. Sera from birds exposed by the oculonasal or by the oral route showed the presence of APV-specific antibodies.

Animals↗
PubMedDate not supplied

Outer membrane proteins for serologic detection of Ornithobacterium rhinotracheale infection in turkeys.

Ornithobacterium rhinotracheale (ORT) is a bacterium responsible for a respiratory disease in turkeys and chickens and has been identified as one of the emerging respiratory bacterial pathogens. The clinical signs and lesions caused by ORT are very similar to those caused by other respiratory infectious agents; therefore, an accurate diagnostic test is necessary to identify the infection. In this study, we have investigated the use of outer membrane proteins of ORT in an indirect enzyme-linked immunosorbent assay (ELISA) to detect the exposure to ORT infection. Outer membrane proteins of ORT were extracted and used as an antigen in ELISA to detect infection in turkeys exposed to different serotypes of ORT. The ELISA results were compared with the conventional serum plate agglutination test. The agglutination test detected specific antibodies for ORT in 65% of experimentally infected turkeys during the first 2 wk of infection. The ELISA detected up to 100% of infected birds for 8 wk postinfection. The results suggest that ELISA is able to detect the exposure to ORT in later stages of the infection and this assay can be used in serologic surveillance of ORT infection for poultry in the field.

Animals↗
PubMedDate not supplied

An atypical fowl pox outbreak in broilers in southern Brazil.

An unusual fowl pox outbreak occurred in two integrated broiler operations. The uncommon characteristic of this outbreak was that the pox lesions were manifested in the feathered parts of the body, mainly in the posterior dorsal area and external part of the thigh. Diagnosis was made by means of histopathology and virus isolation. Severe losses were incurred at the processing plant as a consequence of condemnation due to dermatitis. Vaccination of day-old chicks with mild fowl pox vaccine combined with Marek's disease (HVT) vaccine in the area of the outbreak appeared to be important in controlling the disease.

Animals↗
PubMedDate not supplied

Ornithobacterium rhinotracheale infection in turkeys: experimental reproduction of the disease.

This report details the first experimental production of clinical disease, mortality, and pathology resembling that of field infections by using Ornithobacterium rhinotracheale alone. Twenty-two-week-old male turkeys were exposed to O. rhinotracheale or lung homogenate from O. rhinotracheale-infected turkeys. Within 24 hr after inoculation, turkeys given O. rhinotracheale or lung homogenate intratracheally were depressed and coughing and had decreased feed intake. By 48 hr, several birds were coughing blood and ultimately died. Grossly, the lungs were reddened, wet, and heavy, failed to collapse, and were covered by tenacious tan-to-white exudate. Microscopically, the parabronchi and air capillaries were filled with fibrin, heterophils, macrophages, and small numbers of gram-negative bacteria. The pleura was often covered by a thick layer of fibrin, heterophils, and macrophages. Turkeys that survived to day 7 postinoculation had severe, subacute pneumonia. Ornithobacterium rhinotracheale was recovered from the lungs of most birds with pneumonia and was also cultured from the air sacs, sinuses, tracheas, spleens, and livers. All turkeys inoculated with O. rhinotracheale developed antibodies to O. rhinotracheale detectable by the serum plate agglutination test.

Animals↗
PubMedDate not supplied

Isolation and identification of Ornithobacterium rhinotracheale from commercial turkey flocks in the upper midwest.

Increased death loss was seen in a flock of 22-wk-old tom turkeys. The predominant postmortem lesion was fibrinopurulent pneumonia and pleuritis. Within 5 wk, turkey flocks on 17 other farms developed similar problems. All affected flocks during the 5-wk period were between 14 and 22 wk of age, and the severity of clinical signs and the degree of mortality increased with age. Ornithobacterium rhinotracheale was isolated in pure culture from affected lungs. Further investigation by tracheal swab culture of 261 flocks between 5 and 7 wk of age resulted in detection of O. rhinotracheale in 43% of the flocks.

Animals↗