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Biomedical subjects

P M Terry

Publications and source records attributed to P M Terry.

At least 19 recordsLinked to original sources

Epidemiologic typing of Staphylococcus aureus by DNA restriction fragment length polymorphisms of rRNA genes: elucidation of the clonal nature of a group of bacteriophage-nontypeable, ciprofloxacin-resistant, methicillin-susceptible S. aureus isolates.

Analysis of DNA restriction fragment length polymorphisms of rRNA genes (ribotyping) was employed to assist in the epidemiologic investigation of the emergence and spread of ciprofloxacin-resistant Staphylococcus aureus at the Atlanta VA Medical Center because many isolates of interest were nontypeable by phages and harbored few plasmids useful as strain markers. Chromosomal DNAs of selected S. aureus isolates were digested initially with 20 different restriction enzymes. EcoRI appeared to give the best discrimination of hybridization banding patterns (ribotypes) and was used with all study isolates. Overall, 15 different ribotypes were seen among the 50 S. aureus isolates studied (7 ribotypes among 13 methicillin-susceptible S. aureus [MSSA] isolates and 9 ribotypes among 37 methicillin-resistant S. aureus [MRSA] isolates). Seven of eight ciprofloxacin-resistant MSSA (CR-MSSA) patient isolates had identical antibiograms, were nontypeable by phages, and had a single 22-MDa plasmid. Six of these seven CR-MSSA isolates had an identical ribotype pattern. Ribotyping distinguished this CR-MSSA strain or clone from MRSA and other MSSA isolates, including nontypeable isolates that contained a 22-MDa plasmid. Five ciprofloxacin-susceptible MSSA isolates studied had five ribotypes; one pattern was identical to the CR-MSSA clone. Twenty-three CR-MRSA isolates recovered from the Atlanta VA Medical Center had four different ribotypes. Ribotyping proved to be a useful molecular epidemiologic tool in the study of S. aureus because it differentiated isolates which were indistinguishable by more traditional methods. In addition, this technique demonstrated that at our institution, ciprofloxacin resistance emerged in multiple strains of MRSA, as opposed to primarily a single strain or clone of MSSA.

Bacterial Typing Techniques

Use of plasmid analysis and determination of aminoglycoside-modifying enzymes to characterize isolates from an outbreak of methicillin-resistant Staphylococcus aureus.

We compared disk susceptibility, plasmid analysis, aminoglycoside resistance patterns, and DNA hybridization for their usefulness in characterizing isolates from a hospital outbreak of methicillin-resistant Staphylococcus aureus. Fifteen isolates were susceptible (group 1) and 28 were resistant (group 2) to gentamicin. A total of 15 of 15 (100%) group 1 and 22 of 28 (79%) group 2 isolates carried a 21.5-megadalton plasmid. All group 2 isolates and none of the group 1 isolates possessed a 33-megadalton plasmid. Aminoglycoside resistance pattern determinations revealed the presence of the ANT(4')-I enzyme (aminoglycoside 4' adenyltransferase) in all group 1 isolates but was unable to demonstrate presence of this enzyme in group 2 organisms. The APH(2") + AAC(6')-II enzyme (aminoglycoside 2" phosphotransferase plus 6' acetyltransferase) was found in all of the group 2 isolates but in none of the group 1 isolates. Use of DNA hybridization revealed the presence of the ANT(4')-I enzyme in both groups (group 1, 14 of 15; group 2, 26 of 28). In this hospital outbreak, we found good correlation between disk susceptibility, plasmid profile, aminoglycoside resistance patterns, and DNA hybridization results. It was difficult to predict the presence of the ANT(4')-I enzyme in the presence of the bifunctional [APH(2") + AAC(6')-II] enzyme by the aminoglycoside resistance pattern method because of overlap of the substrate profile.

Anti-Bacterial Agents

Meningovascular syphilis of the spinal cord presenting with incomplete Brown-Séquard syndrome: case report.

A man aged 31 presented to hospital with acute onset of weakness in the legs, sensory loss, and disturbance of bladder and bowel function. Incomplete Brown-Séquard syndrome secondary to meningovascular syphilis of the spinal cord was diagnosed after serological tests for syphilis gave positive results. His condition was probably caused by endarteritis of the arteria radicularis magna of Adamkiewicz. He was treated with procaine penicillin 1.8 MIU intramuscularly once a day and probenecid 0.5 g by mouth three times a day for 21 days followed by physiotherapy and rehabilitation. Considerable neurological recovery was expected. To our knowledge this association has not been reported previously in detail in an English publication.

Adult

Are serological tests of value in diagnosing and monitoring response to treatment of syphilis in patients infected with human immunodeficiency virus?

To assess the value of serological tests in diagnosing and monitoring the response to treatment of syphilis in patients infected with the human immunodeficiency virus (HIV), case notes of eight homosexual men with a history of treated syphilis, positive reactions to serological tests for syphilis, and documented subsequent conversion to HIV seropositivity were studied. No change was noted in serological markers of syphilis after HIV infection. The case notes of one man with primary syphilis, four men with secondary syphilis, and three men with latent syphilis, of whom all were HIV seropositive, were also studied. In seven of these patients the serological responses to infection and after treatment were consistent with the experience of syphilis in HIV seronegative patients. In one man treated for secondary syphilis, and confirmed as HIV seropositive eight months after treatment, the rapid plasma reagin (RPR) test result continued to be positive at a high titre for up to 20 months after treatment.

Acquired Immunodeficiency Syndrome

Development of antibiotic resistance by staphylococcus aureus in a single patient. Confirmation by phage typing, antibiograms, and plasmid analysis.

A patient is described who had colonization and infection with strains of Staphylococcus aureus increasingly resistant to multiple antibiotics while receiving several courses of broad-spectrum antibiotics. S. aureus strains with different phage types, antibiograms, and plasmid profiles were isolated from different sites at the same time. After the patient was transferred to an intermediate-care service where he received only supportive care and no further antibiotics, culture samples from areas previously colonized or infected (sputum, anterior nares, perineal region, rectum) showed no S. aureus. This patient graphically demonstrates that antibiotics may create an environment allowing the overgrowth of resistant organisms and that withdrawal of this selection pressure may allow more sensitive organisms to recolonize.

Adult

Plasmid analysis of simultaneous nosocomial outbreaks of methicillin-resistant Staphylococcus aureus.

A large outbreak of infections caused by methicillin and aminoglycoside resistant Staphylococcus aureus provided the opportunity to evaluate mechanisms of resistance and compare the usefulness of typing systems. Between January 1979 and December 1980, 63 patients developed infections with S aureus resistant to multiple antibiotics, including methicillin and tobramycin. All isolates had an identical antibiogram and were phage type 47/54/75/77/83A. Beginning in January 1981, a superimposed outbreak caused by S aureus of the same phage type but with a resistance pattern now including gentamicin occurred. The two strains contained different aminoglycoside inactivating enzymes. The initial strain contained a single plasmid of 21.5 mDa molecular weight, whereas the subsequent strain which had acquired gentamicin resistance contained this plasmid plus a heavier one of 33 mDa. Plasmid analysis complements the analysis of antibiograms and phage types and aids in defining epidemiologic patterns of transmission.

Bacteriophage Typing

Pseudomonas aeruginosa peritonitis associated with contaminated poloxamer-iodine solution.

Pseudomonas aeruginosa was responsible for four cases of peritonitis and one of wound infection at the catheter site in outpatients on chronic peritoneal dialysis. All organisms had the same antimicrobial susceptibilities and serotype. Culture surveys showed that a strain of Ps. aeruginosa of identical susceptibility pattern, plasmid profile, and serotype was present in bottles of a poloxamer-iodine solution unopened until the time of culture. Both poloxamer-iodine and povidone-iodine solutions have now been shown to be vulnerable to bacterial contamination. Guidelines for their production and use must be reassessed to take this possibility into account.

Ambulatory Care

Hormone-inducible casein messenger RNA in a serum-free organ culture of whole mammary gland.

The whole second thoracic mammary gland of estradiol-17beta + progesterone primed 3- to 4-week-old BALB/c female mice was induced to pregnancy-like lobulo-alveolar morphogenesis after 6-day cultivation in a serum-free culture medium containing a "growth promoting" hormone mixture, insulin + prolactin + growth hormone (somatotropin) + estradiol + progesterone. No radioimmunologically detectable casein was present in these glands. Subsequent cultivation for another 6 days in a "lactogenic" medium with the hormones insulin + prolactin + cortisol produced abundant milk-like secretory material in the alveolar lumen. RNA of the mammary gland after estradiol + progesterone priming or cultivation in the "growth-promoting" medium failed to show a measurable amount of casein mRNA activity when assayed in a cell-free protein synthesis system derived from Ehrlich ascites ribosomes, rabbit reticulocyte factors, and tRNA. However, the glands sequentially cultivated in the "growth-promoting" and the "lactogenic" media showed a high level of casein mRNA activity in the heterologous cell-free protein synthesis system. Sodium dodecyl sulfate/polyacrylamide gel electrophoretic characteristics of the immunoprecipitable (by antibody to mouse milk casein) polypeptides directed by the mammary RNA induced in organ culture medium containing the lactogenic hormones were similar to the characteristics of the polypeptides directed by mammary polysomes of lactating mice. These results demonstrate hormonal induction of a specific mRNA in a sequential two-step culture of an entire organ in a serum-free chemically defined medium.

Animals

Reproducibility of interpretation of the test for antibody-coated bacteria in urinary sediment.

The direct immunofluorescence technique for detecting antibody-coated bacteria in urinary sediment is felt to be useful in distinguishing infection of the kidney from infection of the bladder. An independent, blind multiple-reading system was used to measure interobserver variability in the evaluation of slides of urinary sediments for antibody-coated bacteria. Three independent observers agreed unanimously on first reading in 88% of 253 specimens. When compared with the majority opinion, the sensitivity and specificity of an individual reading were 91 and 95%, respectively.

Bacteria

Susceptibility of Haemophilus influenzae isolates from blood and cerebrospinal fluid to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole.

Susceptibility to ampicillin and chloramphenicol in vitro has been determined for Haemophilus influenzae strains isolated from blood and/or cerebrospinal fluid cultures of patients admitted to two Atlanta hospitals from 1 January 1974 to 31 March 1975. Since the appearance of ampicillin-resistant strains of this organism in early 1974, chloramphenicol has been used in these hospitals as initial therapy for severe infection due to H. influenzae. Strains from five of 94 patients were resistant to ampicillin (minimum inhibitory concentration [MIC] >/= 12.5 mug/ml), but all strains were susceptible to chloramphenicol (MIC < 2 mug/ml). The first 35 strains studied, including three resistant to ampicillin, were also tested for in vitro susceptibility to trimethoprim-sulfamethoxazole; all were highly susceptible (MIC </= 0.0312 mug of trimethoprim and 0.625 mug of sulfamethoxazole per ml).

Ampicillin

An indirect radioimmunoassay for mouse casein using 125I-labeled antigen.

A new indirect radioimmunoassay was developed for detection of casein in mouse milk and in mammary tissue extract. Preincubation of rabbit gamma globulin to mouse milk casein (Ca2+-rennin precipitate) with unlabeled casein, milk, extracts of mammary tissues of late pregnancy and lactation, virtually blocked subsequent binding of 125I-labeled mouse milk casein to the antibody. Preincubation with mouse serum, bovine serum albumin, rennin, extracts of liver or immature mammary tissue had little effect on [125I]casein binding to the antibody. The inability of [125I]casein to bind to the antibody after preincubation with protein samples, which are likely to contain casein, is indicative of a specific antigen-antibody reaction. The assay is capable of detecting 0.2 mug casein, 1 mug milk proteins and 10 mug lactating mammary tissue extract. The application of the assay was also demonstrated using organ culture of the entire mammary gland. The glands treated with the lactogenic hormones, insulin + prolactin + cortisol, showed a saturation level of antibody-antigen reaction, indicating hormonal induction of casein; whereas, no reaction was observed with the non-treated gland.

Animals