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Biomedical subjects

M T Kelly

Publications and source records attributed to M T Kelly.

At least 91 records · Page 5Linked to original sources
PubMed1982

Effect of temperature and salinity on Vibrio (Beneckea) vulnificus occurrence in a Gulf Coast environment.

Vibrio (Beneckea) vulnificus is a recently recognized halophilic organism that may cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be a common inhabitant of marine environments. Twenty-one inshore sites around Galveston Island in the Gulf of Mexico were cultured for V. vulnificus over a 12-month period. The organism was recovered from all but one of the sites at some time during the study. It was frequently isolated during the summer and fall from environments of relatively low salinity (7 to 16%). V. vulnificus was rarely isolated from any of the sites during the winter months, when water temperatures dropped below 20 degrees C. In vitro growth characteristics of environmental isolates of V. vulnificus demonstrated salinity optima of 1.0 to 2.0% NaCl and a temperature optimum of 37 degrees C. These growth characteristics may account for the seasonal and geographical variations in occurrence of the organism. Overall, the results of these studies indicate that V. vulnificus is commonly found in Gulf Coast environments and that the occurrence of the organism is favored by warm temperatures and relatively low salinity.

Humans↗
PubMed1982

Evaluation of the CampyPak II gas generator system for isolation of Campylobacter fetus subsp. jejuni.

The CampyPak II (BBL Microbiology Systems, Cockeysville, Md.) method for isolating Campylobacter fetus subsp. jejuni was evaluated with clinical specimens by comparison with an evacuation replacement procedure. Of 757 specimens, 26 (3.4%) were positive for C. fetus subsp. jejuni. All 26 were recovered by both systems. No difference was found in the time necessary for isolation, except with one isolate that required 3 days for isolation with CampyPak II and 2 days with the established procedure. Although the average colony size was slightly smaller for colonies incubated in the CampyPak II system (P less than 0.02 by a paired t test), this is probably of no practical consequence. In terms of technical performance, therefore, the CampyPak II system appears to be an excellent alternative method for establishing microaerophilic conditions necessary for isolating C. fetus subsp. jejuni. The only difference between the two systems was the cost of using the CampyPak II envelopes. Excluding the initial equipment costs, CampyPak II envelopes cost approximately $0.74 per specimen, whereas the standard Torbal jar technique cost about $0.10 per specimen.

Bacteriological Techniques↗
PubMed1982

Comparison of three automated systems for antimicrobial susceptibility testing of gram-negative bacilli.

Several instruments for automated or semiautomated susceptibility testing are currently available. Three of these instruments, Autobac (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.), MS-2 (Abbott Laboratories, Dallas, Tex.), and AutoMicrobic system (AMS) (Vitek, Inc., Hazelwood, Mo.) were compared for antimicrobial susceptibility testing of gram-negative bacilli. A total of 207 isolates representing 29 species of gram-negative bacilli were tested simultaneously by each instrument and by a standardized disk diffusion reference method. Nine antimicrobial agents, including ampicillin, carbenicillin, cephalothin, gentamicin, tobramycin, amikacin, tetracycline, trimethoprim-sulfamethoxazole, and nitrofurantoin were tested. Discrepancies between the results of the automated and reference disk diffusion methods were resolved by agar dilution testing. Overall, 93% of the Autobac and MS-2 results and 83% of the AMS results were in agreement with the results obtained by the reference methods. The results of the Autobac, MS-2, and AMS systems respectively included 3.3, 2.3, and 4.2% major and very major discrepancies. Excessive testing discrepancies were found for certain drugs, including ampicillin, tetracycline, and nitrofurantoin, and for certain organisms, including species of Providencia, Serratia, and Citrobacter. The results of this comparison of three automated systems for antimicrobial susceptibility testing indicate that the Autobac and MS-2 instruments provided highly reliable results. The AMS need further development of its susceptibility testing capability to eliminate an unacceptably high number of minor discrepancies.

Ampicillin↗
PubMed1982

Isolation of Mycobacterium chelonei with the lysis-centrifugation blood culture technique.

Mycobacterium chelonei was isolated from a patient by the lysis-centrifugation and the conventional two-bottle blood culture methods. The lysis-centrifugation method was significantly more sensitive and rapid than the conventional method in detecting and isolating this organism; quantitations done by this method were useful for monitoring response to therapy.

Adult↗
PubMed1981

Evaluation and optimization of urine screening by Autobac.

The purpose of this investigation was to evaluate the effectiveness of the Autobac (Pfizer Inc., New York, N.Y.) urine screen for detection of bacteriuria in 3,026 urine specimens and to establish the optimum procedure for the Autobac system. Overall, 97% of urine specimens having greater than 10(5) colony-forming units (CFU) per ml were detected within 5 h by the Autobac system. The system detected 66, 90, and 94% of such specimens after 2, 3, and 4 h of incubation, respectively. Of specimens having 10(4) to 10(5) CFU/ml, the Autobac system detected 10, 45, 53, and 95% after 2, 3, 4, and 5 h of incubation, respectively. The rate of false-positive results increased from 0% after 2 h to 2% after 3 h to 6% after 4 h and 25% after 5 h of incubation. The specificity of the urine screening results also varied with the incubation time. Percentages of specimens having greater than 10(5) CFU/ml that gave positive urine screening results at various times were as follows: 96% at 2 h, 74% at 3 h, 29% at 4 h, and 9% at 5 h. These findings suggest that a 3- or 4-h urine screening procedure will effectively detect bacteriuria of greater than 10(5) CFU/ml, with few false-positive results. However, a 5-h procedure, which gives more false-positive results, may be needed for detection of lower levels of bacteriuria.

Bacteria↗
PubMed1981

Comparison of formalin-ethyl ether sedimentation, formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques for detection of intestinal parasites.

Formalin-ethyl ether sedimentation, Formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques were compared using over 250 clinical parasitology specimens. Fifty positive specimens were identified, and a variety of parasites, including amoebae, flagellates, cestodes, nematodes, and trematodes, were encountered. The Formalin-ether and Formalin-ethyl acetate sedimentation procedures gave identical results for the detection of cysts, ova, and larvae, and these methods offered an advantage over the flotation procedure for the detection of selected ova. However, the zinc sulfate procedure was more effective for the detection of protozoan cysts, Hymenolepis nana, and hookworm eggs. The results indicate that the Formalin-ethyl acetate procedure provides a suitable alternative to the Formalin-ether method, and they demonstrate the value of using both flotation and sedimentation procedures in the analysis of fecal specimens for parasites.

Acetates↗
PubMed1981

Rapid identification by the Micro-ID system of Enterobacteriaceae detected by urine screening.

Previous studies have demonstrated that organisms detected by urine screening can be processed for rapid identification and antimicrobial susceptibility testing directly from urine or urine screening broth. In the present study, an improved method for processing such specimens was evaluated. Organisms were harvested by centrifugation from positive urine screening broth, and inocula were prepared for rapid identification by the Micro-ID system and rapid susceptibility testing by the Autobac system. Nearly 2,500 urine specimens were analyzed by urine screening, and 206 specimens had significant growth of gram-negative, oxidase-negative bacilli. These organisms, prepared by the centrifugation procedure, were identified and tested for susceptibility to antimicrobial agents. For comparison, identifications by the Micro-ID system and antimicrobial susceptibility tests by the Autobac system were performed on the same organisms the next day with inocula prepared from colonies growing from standard urine cultures. The results demonstrated that 95% of the organisms were correctly identified by this procedure, and susceptibility testing by the rapid method gave results in 94% agreement with the standard method. These results demonstrate that organisms detected by urine screening can be accurately identified and tested for antimicrobial susceptibility after centrifugation from urine screening broth. This system provides a practical procedure or same-day reporting of urine culture results.

Anti-Bacterial Agents↗
PubMed1981

Effect of moisture content of the medium on colony morphology of Campylobacter fetus subsp. jejuni.

Reduction in the moisture content of the medium produced a profound effect on the colony morphology of Campylobacter fetus subsp. jejuni. Fresh medium produced flat, grayfish, spreading colonies with an irregular shape and variety appearance. Plates that were incubated at 30 degrees C for 48 h produced round, convex, butyrous colonies with an entire edge. Plates incubated at 30 degrees C for 24 h before inoculation produced colonies of an intermediate nature; they were round and raised, but not convex, and slightly water or mucoid in nature. This marked effect produced by moisture content of the medium was reproducible and may account for the variation in colonies observed by other investigators.

Campylobacter↗
PubMed1980

Investigation of the component of Propionibacterium acnes (Corynebacterium parvum) responsible for macrophage activation.

Mouse peritoneal macrophages, activated with Propionibacterium acnes (Corynebacterium parvum) in vivo, exhibited altered morphological characteristics, increased acid phosphatase activity, and release of [EH]thymidine-labeled DNA from tumor cells in vitro. Comparison with macrophages from mice injected with a control organism, P. jensenii, showed that the morphological changes, but not acid phosphatase, correlated with the development of tumoricidal activity. Investigation of the microbial component responsible for this activity indicated it was heat stable and refractory to extraction by methanol-chloroform, dilute acid, butanol, or a serial combination of extraction procedures. When the cells were disrupted by mechanical breakage, no activity could be found in the cell wall, soluble cytoplasm, or particulate cytoplasm. These results suggest that intact organisms are required for macrophage activation, and they may resolve conflicting reports on the nature of the immunostimulating activity of P. acnes.

Acid Phosphatase↗
PubMed1980

Lactose-positive Vibrio in seawater: a cause of pneumonia and septicemia in a drowning victim.

Lactose-positive Vibrio is a recently recognized marine organism that has pathogenic potential for humans. An organism was isolated from the sputum and blood of a man who was resuscitated after drowning in the sea. The isolates from both sources had the characteristics of lactose-positive Vibrio, which include positive oxidase, citrate, indole, and o-nitrophenyl-beta-D-galactopyranoside reactions and negative Voges-Proskauer, urease, and sucrose reactions. Seawater samples from 21 sites around Galveston Island were cultured for lactose-positive Vibrio over a period of 4 weeks, and 36% of the samples yielded the organism. The environmental isolates were very similar to the clinical isolates in biochemical reactions and susceptibility to antimicrobial agents. The results indicate that lactose-positive Vibrio is a common organism in the marine environment and that it should be considered in the diagnosis of infections, including pneumonia, associated with exposure to the sea.

Adult↗
PubMed1980

Comparison of the automicrobic system with API, enterotube, micro-ID, micro-media systems, and conventional methods for identification of Enterobacteriaceae.

Identification of Enterobacteriaceae by the AutoMicrobic System Enterobacteriaceae Biochemical Card was evaluated. Recent clinical isolates of enteric gram-negative bacilli (192) and glucose nonfermenters (3) were identified by the AutoMicrobic System, Micro-Media Systems, Micro-ID, API, and Enterotube II in comparison with conventional methods. The AutoMicrobic System and Micro-Media Systems correctly identified 97% of the organisms tested. Micro-ID, API, and Enterotube II correctly identified 94, 92, and 84% of the organisms, respectively. In addition to a high degree of identification accuracy, the AutoMicrobic System was convenient to operate and produced identification results in 8 h. Operation of the AutoMicrobic System also required minimal personnel time because it automatically monitored and interpreted the biochemical reactions and reported organism identifications. The AutoMicrobic System appears to be an efficient and accurate system for the identification of Enterobacteriaceae.

Bacteriological Techniques↗
PubMed1979

Antimicrobial susceptibility testing of Mycobacterium fortuitum complex.

A total of 24 strains of the Mycobacterium fortuitum complex were tested for susceptibility to antimicrobial agents by the disk diffusion and agar dilution techniques. By comparing zones of inhibition obtained with the disk diffusion technique with results of minimal inhibitory concentration determinations, it was shown that disk diffusion results could predict in vitro susceptibility to selected antimicrobial agents. All of 17 strains of M. fortuitum were susceptible to </=1 mug of amikacin per ml. The corresponding average zone of inhibition around a 10-mug amikacin disk was 37 mm. Seven M. chelonei strains were more resistant to amikacin, with minimal inhibitory concentrations ranging from 1 to 32 mug/ml, and the corresponding average zone size was 21 mm. Susceptibility of both M. fortuitum and M. chelonei to tetracycline was variable and none of the M. chelonei strains was inhibited by polymyxin B, whereas M. fortuitum strains consistently had zones of inhibition around the polymyxin disk. It appears that identification to species of the M. fortuitum complex may be of importance with regard to antibiotic susceptibility. Separation of M. fortuitum and M. chelonei was readily accomplished in the present study by the nitrate reduction and 3-day arylsulfatase tests.

Aminoglycosides↗
PubMed1979

Sputum screening by Nomarski interference contrast microscopy.

Gram-stained smears of specimens submitted for sputum cultures were compared with direct wet mounts examined by Nomarski interference contrast microscopy (NIM) for enumeration of squamous epithelial cells (EPC) and leukocytes (WBC). The results obtained by the two methods were comparable, but specimens were more rapidly screened and cell types were more readily differentiated by NIM. Specimens submitted for sputum culture over a 3-month period were examined for EPC and WBC by NIM. Twenty-two percent of the specimens had greater than 25 EPC/field or a predominance of EPC (class I), 30% had greater than 25 EPC and greater than 25 WBC/field (class II), and 48% had greater than 25 WBC/field or a predominance of WBC (class III). The clinical relevance of the culture results was determined by reviewing the records of patients whose specimens were included in the study. Class I specimens provided only 30% clinically relevant culture results. Specimens in class II provided useful culture results in 63% of the patients, and 96% of those in class III provided clinically relevant information. The results confirm the value of sputum screening and demonstrate that NIM provides a rapid, simple, and accurate method for sputum screening.

Diagnosis, Differential↗
PubMed1979

The value of sonography in suspected ectopic pregnancy.

Of 356 women undergoing sonography to diagnose or rule out an ectopic gestation, data sufficient to assign a final diagnosis were available on 260 of them. Ectopic gestation was diagnosed in 25 cases in this group and intrauterine pregnancy in 99, while the remaining 136 patients were found not to be pregnant. During sonography, ectopic gestations were suspected or diagnosed in 27 instances: In 17 cases this was in agreement with the final diagnosis, but neither an intrauterine nor an extrauterine gestation existed in 10 cases, although neoplastic or inflammatory masses were present. Of the 25 patients with the final diagnosis "ectopic pregnancy," this was not detected with sonography in 8 instances. Intrauterine pregnancies were diagnosed by sonar in 94 of the 99 cases. Although reliable sonar identification of ectopic gestation is not always possible, sonography is helpful in diagnosing intrauterine pregnancy so that surgical intervention can be avoided.

Adolescent↗