Direct Swab Research Articles

Migration of Salmonella Enteritidis Phage Type 30 through Almond Hulls and Shells

The ability of Salmonella to migrate from an external aqueous environment through the almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of almonds that differed in shell hardness were placed in contact with a suspension of Salmonella enterica serovar Enteritidis phage type 30 for 24hat24°C. Salmonella Enteritidis was isolated from the inside of these almond shells in 46 and 100% of the samples, by direct swabbing of the inner surface of the shell and by enrichment from the swab, respectively. These findings suggested that hardness of the shell is not a significant factor in the migration of the pathogen through that tissue. In addition, both motile and nonmotile strains of S. enterica serovar Typhimurium migrated through the almond shells to the same extent under the conditions of this assay, indicating that bacterial migration through the wet shell may be a passive process. Second, whole almonds (intact hull, shell, and kernel) were soaked for 24 to 72 h at 24°C in a suspension of Salmonella Enteritidis phage type 30 labeled with the green fluorescent protein. Green fluorescent protein–labeled Salmonella cells were observed on the outer and inner surfaces of both the almond hull and shell, and on the kernel, by confocal laser scanning microscopy. Our data provide direct evidence that wet conditions allow for Salmonella migration through the hull and shell and onto the almond kernel, thus providing a means by which almond kernels may become contaminated in the field.

Influence of Oral Hygiene Habits on Prosthetic Stomatitis Complicated by Mucosal Infection After Organ Transplantation

Organ transplant patients suffer impaired immunologic defense mechanisms, including antimucosal defenses. The presence of prosthetic appliances within the oral cavity constitutes an additional factor promoting the development of infections. The aim of this study was to evaluate hygiene habits in relation to prosthetic appliances and one’s own teeth practiced by patients after organ transplantation. The study was conducted for prophylaxis of stomatitis complicated by mucosal infection. The research group was composed of patients using prosthetic appliances and undergoing immunosuppressive therapy after kidney or liver transplantation. The control group included healthy wearers of prosthetic appliances. In the course of the initial interview, particular attention was devoted to hygienic habits in relation to the oral cavity and prosthetic appliances, the duration of their use, and the appearance of subjective symptoms. The following examinations concerned the oral mucosal membrane; mouth corners and hygienic condition of prosthetic appliances. Additionally, microbiological examinations were performed by taking a direct swab from the oral mucosa and the surface of dentures. The results of this study showed a greater frequency of prosthetic stomatitis complicated by mucosal infections among patients after organ transplantation, even though these patients exhibited better hygienic standards of the oral cavity and prosthetic appliances.

Candida-Associated Denture Stomatitis in Patients After Immunosuppression Therapy

Patients who undergo kidney or liver transplantation receive long-lasting immunosuppressive therapy. The resultant unfavorable symptoms result from immune deficiency and the side effects of the medications. The aim of this study was to establish the frequency and intensity of denture stomatitis and oral candidiasis among denture-wearing patients who were treated with immunosuppressive drugs. The study was performed in the group of denture wearers with a transplanted kidney or liver who had been treated with immunosuppressive medications. The control group included healthy people wearing dentures. We made physical and clinical examinations in both groups. The history covered nonobjective symptoms in the oral cavity, hygienic habits in the mouth, and the time span during which the dentures had been used. We also evaluated the conditions of the oral mucosal membrane, angular cheilitis, as well as denture stabilization. In both groups mycological investigations were performed by inoculating a direct swab from the oral mucosa and the denture surface on Soborauda agar. The results of our study suggest that patients with immunosuppression were more frequently subject to Candida albicans infections and stomatitis.

Urine Tests for Detection of C trachomatis and N gonorrhoeae

Medicine-Pediatrics| October 01 2005 Urine Tests for Detection of C trachomatis and N gonorrhoeae AAP Grand Rounds (2005) 14 (4): 41. https://doi.org/10.1542/gr.14-4-41 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Urine Tests for Detection of C trachomatis and N gonorrhoeae. AAP Grand Rounds October 2005; 14 (4): 41. https://doi.org/10.1542/gr.14-4-41 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: chlamydia trachomatis, neisseria gonorrhoeae, urinalysis, gold standard Source: Cook RL, Hutchison SL, Ostergaard L, et al. Noninvasive testing for Chlamydia trachomatis and Neisseria gonorrhoeae. Ann Intern Med. 2005;142:914–925. Testing for sexually transmitted diseases poses several logistic barriers for the patient, including making an appointment with a provider and undergoing a pelvic examination with cultures or a urethral swab. The authors, from the University of Pittsburgh, performed a meta-analysis after searching 1991 to 2004 MEDLINE literature to locate all studies of urine testing using the currently available commercial nucleic amplification tests for Chlamydia trachomatis and Neisseria gonorrhoeae. The methodologies covered by these amplification tests included polymerase chain reaction (PCR), strand displacement amplification (SDA), and transcription-mediated amplification (TMA). The authors found 29 studies meeting the predetermined minimum standards, which included presenting data separately by gender, obtaining samples for the same assay on both urine and cervical or urethral sites, and using an appropriate reference standard, the so-called “gold standard.” They pooled results from the 29 studies using both qualitative and quantitative methods. In general, the nucleic acid amplification tests currently available had a very high specificity (>95%) and a reasonably high sensitivity (80% to 93%). PCR testing for N gonorrhoeae in women performed poorly, with a sensitivity of 56%. The authors discussed the limitations of their findings, including the fact that current gold standards for detection of these pathogens are imperfect. They also did not attempt to find unpublished data, such as that submitted to the US Food and Drug Administration for test licensure, which might alter their results. Furthermore, amplification tests do not allow testing for antibiotic susceptibility or for detection of other important diseases such as trichomoniasis. Dr. Robbins has disclosed no financial relationships relevant to this commentary. For the adolescent with evolving privacy concerns, any method to break down logistic barriers to health care access is useful. If noninvasive testing for sexually transmitted diseases were not only easily available but also accurate, perhaps adolescents would seek care more readily for these disorders. The authors of this meta-analysis do a nice job of locating and combining all known data comparing nucleic amplification tests of urine samples to the gold standard of direct swab and culture for chlamydia and gonorrhea. The pooled specificity was quite high, which makes these tests useful for “ruling in” disease requiring treatment. The general pediatrician, however, is more interested in “ruling out” these infections in adolescents who present with genital complaints, and this requires a test with high sensitivity. The pooled sensitivities reveal negative likelihood ratios of 0.07 to 0.2, which generally are good enough to rule out disease in patients whose probability of having chlamydia or gonorrhea is no greater than 20% to 30%. (For a review of use of sensitivity and specificity to rule in or rule out a disease, see AAP Grand Rounds, June 2003;9:65.) It is up to the practitioner to decide whether the patient’s likelihood of disease is higher than this. If so, urethral... You do not currently have access to this content.

Real‐Time PCR Improves Detection of Trichomonas vaginalis Infection Compared With Culture Using Self‐Collected Vaginal swabs

OBJECTIVE: To compare a real-time polymerase chain reaction (PCR) assay with broth culture for the detection of Trichomonas vaginalis using self-collected vaginal swabs. METHODS: Self-collected vaginal swabs were obtained from adolescent and young adult African-American women participating in HIV-1 prevention programs. T. vaginalis culture was performed using the InPouch TV System. Samples for the real-time PCR assay were collected using the BDProbeTec ET Culturette Direct Dry Swab system and tested in a laboratory-developed assay which targeted a repeated sequence of the genome. Discrepant samples that were culture negative and positive in the real-time PCR assay were tested in a confirmatory PCR which targeted a different region of the T. vaginalis genome, the18S ribosomal DNA gene. RESULTS: Of the 524 specimens tested by both culture and real-time PCR, 36 were culture positive and 54 were positive in the real-time PCR assay; 16 of the 18 discrepant specimens were also positive in the confirmatory PCR assay. Using a modified gold standard of positive by culture or positive in both PCR assays, the sensitivity of the real-time PCR assay was 100% and the specificity was 99.6%, whereas culture had a sensitivity of 69.2% and a specificity of 100%. CONCLUSIONS: The real-time PCR assay was sensitive and specific for the detection of T. vaginalis DNA from self-collected vaginal swab specimens. The ability to use the BDProbeTec dry swab system for the real-time PCR testing allowed for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and T. vaginalis from a single specimen.

Validation and assessment of a blood-donor arm disinfectant containing chlorhexidine and alcohol.

To minimize the bacterial contamination rate in blood collected from donors, a study was designed to evaluate the suitability of a single-use chlorhexidine-alcohol antiseptic for donor arm preparation at all blood collection venues in Australia. A prospective study of bacterial load on the skin was performed on 616 blood donors' arms before and after disinfection using a direct swabbing and plating technique. Disinfection was achieved with a swab containing 1 percent chlorhexidine gluconate with 75 percent alcohol, which was applied to the skin in a prescribed method. Feedback from blood donors and staff was obtained using questionnaires. After disinfection, 99 percent of donor arms had bacterial counts of 5 cfu per plate or less, and 99.5 percent had counts of 10 cfu per plate or less, respectively. The mean colony count for all donors after disinfection was 0.39, and the percentage reduction was 99 compared to predisinfection. Sixteen donors (3%) noted transient skin irritation. The majority of staff (64%) preferred not to use the new disinfectant due to the difficulty opening the packaging and an excessive amount of antiseptic solution per pack. The bacteriologic study showed that the disinfectant satisfied the requirements of the Australian Red Cross Blood Service for use to prepare blood-donor arms before venesection. An improvement to the packaging was required before it could be acceptable to all staff.

Rectoanal mucosal swab culture is more sensitive than fecal culture and distinguishes Escherichia coli O157:H7-colonized cattle and those transiently shedding the same organism.

Enrichment and direct (nonenrichment) rectoanal mucosal swab (RAMS) culture techniques were developed and compared to traditional fecal culture for the detection of Escherichia coli O157:H7 in experimentally infected and naturally infected cattle. Holstein steers (n = 16) orally dosed with E. coli O157:H7 were sampled after bacterial colonization starting 15 days postinoculation. Enrichment RAMS cultures (70.31% positive) were more sensitive than enrichment fecal cultures with 10 g of feces (46.88% positive) at detecting E. coli O157:H7 (P < 0.01). Holstein bull calves (n = 15) were experimentally exposed to E. coli O157:H7 by penning them with E. coli O157:H7-positive calves. Prior to bacterial colonization (1 to 14 days postexposure), enriched fecal cultures were more sensitive at detecting E. coli O157:H7 than enriched RAMS cultures (P < 0.01). However, after colonization (40 or more days postexposure), the opposite was true and RAMS culture was more sensitive than fecal culture (P < 0.05). Among naturally infected heifers, enriched RAMS or fecal cultures were equally sensitive (P = 0.5), but direct RAMS cultures were more sensitive than either direct or enriched fecal cultures at detecting E. coli O157:H7 (P < 0.01), with 25 of 144, 4 of 144, and 10 of 108 samples, respectively, being culture positive. For both experimentally and naturally infected cattle, RAMS culture predicted the duration of infection. Cattle transiently shedding E. coli O157:H7 for <1 week were positive by fecal culture only and not by RAMS culture, whereas colonized animals (which were culture positive for an average of 26 days) were positive early on by RAMS culture. RAMS culture more directly measured the relationship between cattle and E. coli O157:H7 infection than fecal culture.

An optimised recovery method for thermophilic Campylobacter from liver.

The past three decades have witnessed the rise of Campylobacter enteritis in man from virtual obscurity to notoriety, with present isolation rates superseding those of other enteric pathogens such as Salmonella spp. and Shigella spp. in most developed countries. Although campylobacters are not completely new to applied bacteriology, they have evaded traditional isolation techniques used for the isolation of pure cultures, apart from single isolations that were free from competing organisms. Offals, in particular liver have been described as both a source of campylobacters, as well as a route of transmission of this organism to human. Therefore, the aim of this study was to develop an optimum method for the recovery of Campylobacter spp. from porcine liver. Four isolation techniques (methods A-D) were compared in a small pilot study for their ability to successfully recover campylobacters from freshly eviscerated porcine liver. The optimum isolation method involved direct swabbing of the liver tissues followed by plating onto Preston Selective medium, which was superior to methods involving mechanical disruption to liver tissues, including direct plating and enrichment methods, with and without blood. Consequently, any isolation method that involves disruption of liver tissue e.g. homogenisation or stomaching, is not suitable for the detection of campylobacters from liver and hence it is recommended that employment of a direct swabbing technique without mechanical disruption of tissues in combination with selective plating to optimally recover campylobacters from freshly eviscerated liver. Employment of a direct swabbing technique in combination with selective plating allow Campylobacter spp. to be optimally recovered from freshly eviscerated liver and therefore this technique is recommended when examining liver for the presence of this organism.

Compatibility of the thinprep pap test and the LCX probe system chlamydia trachomatis assay

Objective: To determine the compatibility of sensitive-amplified DNA laboratory testing for Chlamydia with fluid-based cytological specimens collected for Pap testing.Methods: Cervical scrapes were collected from 443 subjects into liquid preservative for the ThinPrep Pap Test using the cytobrush and spatula collection technique. After a thin layer slide was prepared for cytological evaluation, a second slide was prepared for Chlamydia detection by direct fluorescence assay (DFA). The thin layer slide result was blinded and compared to a conventional slide prepared using a swab specimen from the same subjects. One milliliter was then removed from each vial of remaining specimen and processed for the Ligase Chain Reaction (LCR) Chlamydia assay by using a slight modification of the routine procedure used for urine specimens. Vials determined to have inadequate endocervical components by either ThinPrep or conventional DFA were excluded from the study. LCR results from the adequate vials were then compared with the DFA results from subjects for whom both ThinPrep and conventional DFA results agreed.Results: Of 410 adequate specimens, a statistically significant increase was observed in the positive rate of LCR (59/410 or 14.4%) with respect to consensus DFA (38/410 or 8.8%). Only 2 consensus DFA-positive specimens (0.5%) were negative by LCR and remained negative upon retesting. Of the 8 specimens that were DFA discrepant, the LCR results favored ThinPrep 50% of the time.Conclusions: LCR testing for Chlamydia is compatible with specimens collected for the ThinPrep Pap Test with an expected increase in sensitivity. This feasibility study provides the impetus for a blind comparison trial between direct LCR swab and ThinPrep Pap Test collections.

Low levels of antigenic variability in fluconazole-susceptible and -resistant Candida albicans isolates from human immunodeficiency virus-infected patients with oropharyngeal candidiasis.

Three serial isolates of Candida albicans were obtained by direct swab or by oral saline rinses from each of five human immunodeficiency virus-infected patients with recurrent oropharyngeal candidiasis. Genotyping techniques confirmed the presence of a persistent strain in multiple episodes from the same patient, which was different from the strains isolated from other patients. Fluconazole susceptibility was determined by both an agar dilution method and the National Committee for Clinical Laboratory Standards macrobroth procedure. In four of these patients the strains developed fluconazole resistance, and in one patient the strain remained susceptible. The different isolates were propagated as yeast cells on a synthetic medium, and their cell wall proteinaceous components were extracted by treatment with beta-mercaptoethanol. Protein and mannoprotein components present in the extracts were analyzed by electrophoresis, immunoblotting, and lectin-blotting techniques. The analysis showed a similar composition, with only minor qualitative and quantitative differences in the polypeptidic and antigenic patterns associated with the cell wall extracts from serial isolates from the same patient, as well as those from different strains isolated from different patients. Use of monospecific antibodies generated against two immunodominant antigens during candidiasis (enolase and the 58-kDa fibrinogen-binding mannoprotein) demonstrated their expression in all isolates tested. Overall, the antigenic makeup of C. albicans strains remained constant during the course of infection and was not affected by development of fluconazole resistance. In contrast to previous reports, the low degree of antigenic variability observed in this study may be due to the fact that the isolates were obtained from a highly homogeneous population of patients and to the uniformity in techniques used for the isolation, storage, and culture of the different strains, as well as extraction methodologies.

Effectiveness of cleaning techniques used in the food industry in terms of the removal of bacterial biofilms.

The effectiveness of cleaning was investigated through food factory trials and laboratory experiments using a naturally occurring biofilm from a food factory environment and generated biofilms. The efficacy of factory cleaning and disinfection programmes was assessed by swabbing and total viable count (TVC) analysis of surfaces before cleaning, after cleaning and after disinfection. Cleaning produced a 0.91 log reduction in the attached population. Investigation of the effectiveness of a variety of cleaning methods in the removal of a naturally occurring food factory biofilm showed that the high pressure spray and the mechanical floor scrubber, which use a high degree of mechanical action, were most effective. Cleaning trials with biofilms of Pseudomonas aeruginosa or Staphylococcus aureus showed that spraying with water at pressures of 34.5, 51.7 and 68.9 bar did not significantly increase the removal, as assessed by direct epifluorescent microscopy (DEM) and swabbing and TVC analysis, beyond the three log reduction observed at 17.2 bar. The effect of spray time at 17.2 bar showed that increasing spray time from 1 to 10 s did not significantly increase removal of Ps. aeruginosa biofilm. Investigation of the optimum distance of the spray lance from the surface at 17.2 bar was found to be between 125 and 250 mm. The use of an alkaline, acidic or neutral detergent prior to spraying with water at 17.2 bar did not significantly increase the removal of Ps. aeruginosa or Staph. aureus. However, the acidic and alkaline products significantly (P = 0.05) affected the viability of Staph. aureus and Ps. aeruginosa, respectively, thereby minimizing the potential for the spread of contamination.

Occurrence of Thermophilic Campylobacter spp. in Porcine Liver in Northern Ireland

Pork livers (400) from bacon pigs (37 herds) obtained at six pork-processing plants in Northern Ireland were studied to assess the rate of contamination with Campylobacter spp. These animals average 95 to 100 kg live weight. Deep tissue areas were sampled immediately postevisceration and revealed that ca. 6% of livers were infected with Campylobacter spp., consisting of C. coli (67%), C. jejuni (30%) and C. lari (3%). Mean log10 CFU g−1 for aerobic plate count and coliforms were 3.60 and 2.94 respectively, indicating reasonable maintenance of slaughter-house hygiene procedures. A combination of direct swabbing of liver coupled with plating on both Skirrow and Blaser-Wang selective media was the most efficient combination of selective media employed. These data confirm the presence of Campylobacter spp. in porcine liver, thereby emphasizing the need to define safe Processing parameters in the manufacture of liver-based products that are subjected to mild thermal processes, in order to eliminate the risk of disease to man.

Use of the Petrifilm™ Test Kit-HEC Direct Blot Enzyme Immunoassay Method without Swab Pre-Enrichment to Screen for Low Levels of Escherichia coli O157 : H7 on Beef Carcasses by Surface Swabbing

A total of 750 beef carcasses were assayed to detect E. coli O157:H7 by surface swabbing. Each swab represented a 200-cm2 composite surface area. Escherichia coli O157:H7 was not detected in any of the carcass samples. Assays were conducted from carcass swab suspensions by direct plating on Petrifilm™E. coli Count plates followed by an E. coli O157:H7 assay using the Petrifilm™ Test Kit-HEC direct blot enzyme immunoassay without sample pre-enrichment, and by enrichment using a modified U.S. Department of Agriculture (USDA) Petrifilm™E. coli O157:H7 procedure. Additionally, beef slabs were inoculated with E. coli O157 :H7 to verify that recovery by the direct swab technique was at least as efficient as enrichment of excised tissue samples, which is the usual USDA method. Escherichia coli O157:H7 inoculation of 4,32, and 180 CFU/25 cm2 were designated low, medium, and high surface contamination levels, respectively. The percentage of recovery of E. coli O157:H7 using the direct swab technique without sample pre-enrichment was 60, 80, and 100% for low, medium, and high surface inoculation levels, respectively. In comparison, recovery from 25-g enrichments of ground excised samples from beef slabs containing 1.4,9.6, and 50 CFU of E. coli O157:H7 was 0, 20, and 73%, respectively. Similarly, the percent recovery of this organism from nonground excised samples containing 56 CFU/25 g enrichment was 68%, versus 100% by direct swab technique without sample pre-enrichment from beef containing 190 CFU/25 cm2 Direct surface swab tests with the 3M Petrifilm™ Test Kit-HEC without sample pre-enrichment proved to be a sensitive, nondestructive, alternate means of evaluating beef carcasses for the presence of E. coli O157:H7.

Development of surface swabbing procedures for a cleaning validation program in a biopharmaceutical manufacturing facility

Validation of direct surface swabbing procedure in conjuction with total organic carbon (TOC) analysis is described for a biopharmaceutical product manufacturing operation. The swabbing technique was found to be very effective in reliably detecting very low levels of residuals for diverse process streams (limit of detection of approximately 0.5microg/cm(2)). However, contaminant recovery was significantly dependent on both the type of contaminant and the processing surface. This study serves as a guide for designing effective cleaning validation protocols based on direct surface swabbing techniques. (c) 1995 John Wiley & Sons, Inc.

Effect of management practices on the Streptococcus suis carrier rate in nursery swine

Summary Management practices on swine farms were analyzed to determine factor(s) associated with high prevalence of pigs that were carriers of Streptococcus suis. Samples were obtained for bacteriologic culture via direct swabbing of palatine tonsils of healthy nursery pigs on 35 farms throughout the United States. Overall, 36.7% of the pigs were determined to be carriers. Isolates of S suis were serotyped, and antimicrobial susceptibility tests were performed by use of Kirby-Bauer techniques. Streptococcus suis types 1 and 2 were most commonly isolated. All isolates were susceptible to enrofloxacin, 97% of the isolates were susceptible to ceftiofur, and 94% were susceptible to ampicillin. However, only 80% of the isolates were susceptible to penicillin, and only 18% were susceptible to tetracycline. Environmental, managerial, nutritional, and health factors were measured on each farm. Excessive temperature fluctuation, high relative humidity, crowding, and an age spread of &gt; 2 weeks between pigs in the same room were the 4 most commonly encountered problems on farms with higher-than-average percentages of carrier pigs. Continuous flow facilities were found on 50% of these farms, and various disease problems, vitamin E/selenium deficiency, inadequate vaccination programs (attributable to the presence of atypical serotypes), and penicillin-resistant strains were found on 6 to 28% of these farms. Overall, 83% (15/18) of farms with higher-than-average percentages of carrier pigs also had a history of clinical S suis disease.

Bacteriology of tonsil and adenoid and sampling techniques of adenoidal bacteriology

The value of pernasal swabs and direct adenoid swabs in chronic adenoid and adenotonsillar disease was assessed in 175 patients. Prior to adenoidectomy (53 patients) or adenotonsillectomy (122 patients), pernasal and direct adenoid swabs were taken. Adenoid currettings and tonsil tissue were cultured. Haemophilus influenzae was the bacterium most frequently isolated from adenoid currettings and from the centre (core) of the resected tonsil. There was a close relationship between the bacteriology of the pernasal swab and the adenoid tissue and tonsil core in 72 and 71% of patients, respectively. There was an identical profile of pathogens in 52 and 49%, respectively. We suggest that in children with adenoiditis or adenotonsillitis and hypertrophy of the adenoid, a pernasal swab should be used in preference to a throat swab in selecting appropriate antimicrobial therapy. Penicillin and ampicillin are not appropriate blind therapy in chronic adenoid and adenotonsillar infections because of the prevalance of β-lactamase-producing aerobes (40%) in adenoid and tonsil core in these conditions.

Does Spray Washing of Lamb Carcasses Alter Bacterial Surface Contamination?

In order to ascertain clean slaughter and dressing procedures, the individual steps within the slaughter process have to be monitored for possible sources of contamination. In sheep slaughter those work processes in connection with skinning and evisceration have to be recognized as critical control points. In both the above areas of work, contamination of the carcasses does occur frequently. For the microbial assessment of postevisceration spray washing used frequently in line slaughter, 50 sheep carcasses were sampled, using replicate organism direct agar contact plates and swabs. A total of 900 tests were performed for total aerobic plate counts and for Enterobacteriaceae. Sampling commenced immediately after skinning, using the following sites: dorsal site (lumbar area), brisket (near xyphoid), medial side of hindquarter (proximal knee joint), medial side of forequarter (proximal elbow joint), as well as the skinned head (masseter). The results can be summarized as follows: Spray washing leads to bacterial contamination of the dorsal area of sheep, i.e., a portion of the carcass less likely soiled by the slaughter personnel. According to our experimental design, spray washing does not reduce nor increase bacterial contamination of the ventral area of sheep, i.e., a portion of the carcass most likely soiled by the slaughter personnel. Thus, spray washing does not improve the microbial status of sheep carcasses. As any additional water remaining on the carcass - apart from all that was stated above - enhances multiplication of bacteria in the long run, we do not regard spray washing a desirable asset in slaughter technology.

A comparison of direct immunofluorescence, shell vial culture, and conventional cell culture for the rapid detection of influenza A and B

Direct immunofluorescence (FA) and shell vial contrifugation cultures (SVCs) were compared with conventional tube cultures for the rapid detection of influenza A and B by using a commercial antibody. Of the 439 specimens tested, 82 were positive by conventional culture (CC). The direct smear prepared from pelleted cells or direct swab material exhibited positive fluorescence in only seven (8.5%) of these cases, whereas the SVC was positive in 30 (37%). The SVC method detected 12 additional positive isolates that were not recovered in CC. The mean time to isolation in CC was 3.6 days for influenza A and 4.3 days for influenza B. The use of SVC provided more rapid results (36-48 hr). The FA method, although more rapid, may be of limited sensitivity and difficult to interpret depending on the quality of the specimen. The results indicate that SVC complements conventional culture in the rapid detection of influenza and can detect infections that may be missed in conventional tubes, but should not be used to the exclusion of conventional culture.

Comparison of Three Sampling Techniques for Microbiological Analysis of Meat Surfaces

ABSTRACTEfficiencies of three surface sampling techniques were compared for estimating total aerobic microflora, total coliform, fecal coliform and Escherichia coli. They were: stomaching excised skin (a destructive technique), direct agar contact and double moist swab (nondestructive techniques). Thirty ovine carcasses were evaluated for surface contamination, with sampling on three different dates. Difference between the three methods of sampling was significant for all bacterial groups evaluated. Stomaching excised skin recovered the highest number of bacteria. Moreover, significant differences in counts were observed with periods of sampling. For total aerobic microflora, counts appeared to be influenced by both sampling technique and sampling date.

Topical antimicrobial testing of burn wound micro-organisms: Evaluation of a new technique

A new system of determining susceptibility of burn wound micro-organisms to topical antimicrobial therapy was studied. The new method, TOPITEST, employs a methacrylate vehicle impregnated with various antimicrobial agents and an agar overlay. Test plates can be inoculated by a direct swab culture of the wound or with micro-organisms isolated by other methods. This new technique was compared to an agar well diffusion (AWD) method using commercially compounded antimicrobials and biopsy-recovered organisms. The new test method provided comparable results to the more established AWD test when using biopsy-recovered organisms. Using the swab culture technique, however, TOPITEST had a high rate of failure to recover sufficient organisms from the burn wound for testing. The new, more standardized test provided results earlier than the AWD test, but may prove to be less cost effective.