Since 1928, 22 professional agencies have established certification procedures for 52 categories or levels of health laboratory personnel. Surveys indicate that 55% of technical personnel are certified by at least one registry or board. After reviewing some of the pros and cons of certification and its expanding role, the author concludes that certification has become a positive factor in calling attention to the need for quality personnel in health laboratories and has helped meet the needs of individuals and the public. Current movements to work together in a National Commission for Health Certifying Agencies and toward national certification standards are encouraging.
A Minitek basic 9 disc/11 test system plus arabinose, inositol and rhamnose was compared with a conventional six tube screening system for identification of members of the family Enterobacteriaceae. Correlation varied from 88.3 to 100% with the various substrates when studied against 737 strains of these and other gram-negative bacteria recently isolated in our clinical laboratory. Two discs, citrate and ornithine, which originally gave a correlation of 88.3 and 95.5% respectively were modified so that a final correlation of 99.4 and 96.3% was obtained. The average correlation using the eleven discs was 97%.
The macroscopic rapid plasma reagin (RPR) and reagin screen (RST) card tests for syphilis were compared. Test specimens were also examined with the Venereal Disease Research Laboratory (VDRL) microscopic slide test; those reactive in the card or slide tests were examined with the fluorescent treponemal antibody-absorption (FTA-ABS) procedure. Agreement between the card tests with 2,300 specimens was 99%; among all three reagin tests it was 96.3%. With 348 specimens reactive in one or more of the tests, there was 75.6% agreement among all three tests. The FTA-ABS was reactive with 71% of the RPR- or RST- and 65% of the VDRL-reactive specimens. The comparison showed that the card tests give results in close agreement with those of VDRL while offering a number of practical advantages over it.
Determination of Staphylococcus aureus enterotoxin type B using ELISA is described. The ELISA is more sensitive than the micro-slide technique. The specificity of the determination of enterotoxin B depends on the specificity of the antisera used. Application of this new assay is evaluated and discussed.
While studying variations amony immunizing potentials of rabies vaccines, we were led to consider the possibility that the antigen in the vaccine derived from duck embryos may have been degraded by enzymes arising from host tissues. Such an enzyme, a neuraminidase, was found in duck embryo rabies vaccine through the application of a periodate-linked thiobarbituric acid assay. This acitvity could not be found in two other rabies vaccines derived from tissue cultures. We have thus concluded that there is a strong possibility that a modified antigen is present in duck embryo vaccine. In addition, the injection of this vaccine will introduce a neuraminidase which may produce localized effects in the tissues of the recipient.
A systematic survey of blood samples from 174 industrial workers occupationally exposed to lead fumes and lead dust, revealed some poor correlations between the lead (Pb) level and the free erythrocyte protoporphyrin (FEP) level. In addition to those workers who had an expected correlation (normal Pb-normal FEP or elevated Pb-elevated FEP) there were two groups with atypical correlations. In one group a normal Pb level was associated with an elevated FEP level and in the other group an elevated Pb level was associated with a normal FEP level. This shows that neither the Pb nor the FEP test can substitute for the other. Since the individual FEP response to Pb absorption is unpredictable, both tests should be carried out routinely. This would make it possible to determine simultaneously the degree of absorption (Pb level) and the degree of intoxication (FEP level) and would improve significantly the assessment of undue lead absorption of occupationally exposed workers. If, however, only one of these tests is used for screening the other test should always be carried out as a confirmatory test when the screening detects an elevated Pb or FEP level.
The National Institute of Health Guidelines for Recombinant DNA Research recommends 2% aqueous Wescodyne, an iodophore that is used in many hospitals and laboratories as a disinfectant, as a decontaminant for biological safety cabinets and 5% for a spill outside a cabinet. A contact time of 10 to 15 minutes was given for the 2% solution and 20 minutes was considered adequate for the 5% concentration. The results indicate: 1. Aqueous Wescodyne (5%) is ineffective when used for 80 minutes against poliovirus in a test mixture containing 8.5% bovine serum albumin (a mixture equivalent in protein concentration to the higher range in serum). 2. Wescodyne (10%) employed under the same conditions for 40 minutes is also ineffective. 3. Wescodyne (10% v/v) in 50% ethanol (w/w) was effective and this mixture, originally recommended for hand washing, should be considered for use in biohazard situations, particularly for decontamination of work surfaces and biological safety cabinets. These results are of significance for if a virucide cannot inactivate poliovirus one would be concerned about using the virucide against hepatitis B or SV40 viruses.
A series of six flow charts have been developed to identify the Gram-negative nonfermentative bacilli most commonly isolated from clinical specimens. Colonial morphology and oxidase reactivity determine the pathway to be followed on the flow chart which then indicates the specific test to be performed. Most isolates can be identified within 24 hours using 3 to 5 tests. Each pathway was selected on the basis of 94-100 per cent confidence limits otherwise an alternate pathway is shown. Results of 2,788 nonfermenters identified by this scheme are discussed.
The incidence of infections due to Serratia marcescens increased steadily at the Veterans Administration Hospital in Pittsburgh, Pennsylvania from 1970 to mid 1975 followed by a decline extending into 1977. One hundred eighty-four Serratia marcescens isolates were collected from 123 patients over a 4-month period in 1975 and were characterized by stereotype and antibiotic sensitivity. Three-fourths of the isolates were clinically significant. Among 24 stereotypes O-:H2 predominated in the urinary tract and O-H12 in respiratory secretions. Clusters of serotypes were on occasion identified in the GU Surgery Ward and the Intensive Care Unit. Uninary isolates showed remarkable resistance to antibiotics; only two thirds were susceptible to amikacin, the most effective agent in vitro. The patients from whom Serratia was isolated were older than the general hospital population (60 vs. 53.6 years of age), were hospitalized longer than the age-corrected controls (62 vs. 34.5 days) and two-thirds of thirds of them acquired the infection in the hospital. Uninary catheterization and prior antibiotic therapy were significant risk factors for urinary infections, and prior surgery contributed to recovery of Serratia from the respiratory tract. Serotype and antibiotype differences between isolates from the urinary and those from the respiratory tract suggest that strains evolved a site specificity.
An axenic culture of Acanthamoeba culbertsoni, strain A-1, was obtained from the American Type Culture collection and injected, via the cisterna magna, into the subarachnoid space of dogs. Attention was focused on the pleomorphic surface specialization of the pathogens suspended in cerebrospinal fluid and compared with those from trypticase soy broth suspensions. Light and scanning electron microscopic comparisons of both inoculated and stock (control) specimens demonstrated similar surface features such as microvillous-like to bleb-like microappendages projecting from variably smooth to undulating membranous exteriors. This study introduces a potentially useful morphological technique that could possibly be of assistance in the more rapid diagnosis of these infections facilitated by SEM screening of the cerebrospinal fluid.
This article will try to point out an often over-looked tool of management that most laboratory technologists are familiar with. The laboratory technologists that suddenly find themselves as chief technologists or managers would do well to remember their bench training. Specifically, document everything you do. The article lists suggestions and examples pertaining to documentation, that chief technologists could well benefit from. Four specific examples of documentation forms are as follows, (1) Pre-employment evaluation interview, (2) Laboratory orientation check list, (3) Documentation of employee counseling, and (4) Report of corrective interview.
An antigen extracted and purified from Neisseria gonorrhoeae B370, type 4, was employed to sensitize charcoal particles for use in an agglutination assay of human sera for antibodies that indicate active gonorrheal infection. The screening card test is more sensitive than the fluorescent gonorrheal test-heated (FGT-H), especially in men. A simple one-step absorption improved the specificity without reducing the sensitivity of the test.
From a survey of 22 U.S. veterinary schools and the university campuses where they are located, it was found that none of the schools had a full- or part-time health and safety officer whereas 16 campuses did. On 18 campuses some form of safety committee existed whereas such committees had been formed in only 12 schools. There was no relationship between the level of school or campus safety organization and presence (10 schools) or absence (12 schools) of an OSHA approved state occupational safety and health plan. An occupational health "bookshelf" reference list is appended.
Appropriate methods and criteria for judging the degree of sewage contamination of water and its suitability for drinking or recreational uses are essential to safeguard the public health. 5beta-cholestan-3beta-ol seems to satisfy many, if not all, of the criteria required of a good indicator of fecal pollution. It was shown that this fecal sterol was strongly adsorbed to the polystyrene polymeric XAD-2 adsorbents at low pH, resulting in a 100% retention. The adsorbed sterols could be easily removed from the columns with acetone adjusted to pH 8.5-9 with concentrated NH4OH. It has also been demonstrated that large volumes of both fresh and sea water samples can be extracted by the "closed" column method in a relatively short time. The sensitivity of the column exceeded that of the conventional liquid-liquid partitioning procedure. With some modifications, the column extraction process can be incorporated in a fully- or semi-automated analytical procedure.
Mouse immune ascitic fluid has become a primary source of antibody for diagnostic, reference, and research work in many virus laboratories. The inherent disadvantage of ascitic fluid is that it repeatedly forms clots and subsequently loses volume. The acid-precipitation method of Chiewsilp and McCown eliminates the clot formation and does not appreciably alter the antibody titers for several arboviruses, varicella, rabies and influenza viruses.
This survey examined quality assurance practice in matched pairs of rural and urban hospital clinical laboratories. Questions directed at personnel qualifications, laboratory management, internal quality control mechanisms, and proficiency testing enrollment revealed no major differences between the rural-urban pairs. Deficiencies observed were either generic or size-related. Most laboratories were directed by physicians; however, almost half spent 5 or less hours per week in the laboratory. All respondents employed at least one individual professionally certified at the "technologist" level. Virtually all respondents insisted they employ a laboratory management system for ensuring quality performance, although 20% did not document their practice. Internal quality control practice varied widely. Many respondents recognized shortcomings related to volume and budget, and requested specific training courses for technical personnel. At least 20% of the laboratories were not enrolled in any recognized proficiency testing program, an integral part of the total quality assurance process.
