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PubMed1996

Spermatic cord contamination in testicular cancer.

It is not uncommon to find testicular germ-cell tumors in the spermatic cord. This may represent contamination or true involvement (vascular invasion or direct tumoral extension into the cord). A correct identification of the process has important clinical implications. In a review of 326 testicular germ-cell tumors, 79 (24.2%) revealed tumor in the spermatic cord. Of these 79, contamination was found in 57 (72.1%), true involvement in 15 (19%), and true involvement and contamination in 7 (8.9%). Spermatic cord contamination was seen most frequently with seminomas: 34 (24.1%) of 141 seminomas and 20 (15.4%) of 130 mixed germ-cell tumors. Eighteen of the 20 mixed germ-cell tumors contained an embryonal carcinoma component. True involvement was seen most frequently in embryonal carcinoma. Six (15.4%) of 39 pure embryonal carcinomas demonstrated true cord involvement. Six mixed germ-cell tumors with true cord involvement contained an embryonal carcinoma component. Distinguishing between true involvement of the spermatic cord and contamination can occasionally be problematic. Because true involvement, especially at the spermatic cord resection margin, identifies patients at a high risk for relapse, the problem of contamination caused by inadequate precautionary measures can be avoided by meticulous handling and processing of the specimens.

False Positive Reactions↗

PubMedDate not supplied

Saliva contamination of dentin bonding agents.

This study examined the shear bond strength to dentin of two dentin bonding agents when contaminated with a measured amount of saliva at various stages in their application procedure. Eighty extracted human third molar teeth were randomly separated into four groups of 10 for each of the dentin bonding systems tested (All-Bond 2, Scotchbond Multi-Purpose). Group A specimens were not contaminated; primer/adhesive/resin were applied according to manufacturers' instructions. In Group B, samples were contaminated for 15 seconds with fresh whole human saliva, and then forcibly dried with a blast of oil-free air; this occurred after application of the primer but prior to application of adhesive. In Group C, contamination occurred after application of adhesive, prior to application of resin. In Group D, saliva was allowed to contaminate the surface as the primer was being applied, without forcible removal. Specimens were then thermocycled, mounted, and tested in shear on an Instron at 7 days. Bond strengths in MPa were obtained, and data were analyzed using a one-way ANOVA, at the P = 0.05 level of significance. Although shear bond strengths were lowered in saliva-contaminated samples, there was no statistically significant difference between group means.

Analysis of Variance↗

PubMed1996

High degree of occult tumor contamination in bone marrow and peripheral blood stem cells of patients undergoing autologous transplantation for non-Hodgkin's lymphoma.

Twenty patients with non-Hodgkin's lymphoma (NHL), primarily intermediate-and high-grade, were evaluated for evidence of bone marrow (BM) or peripheral blood stem cell (PBSC) lymphoma contamination using tumor-specific oligonucleotide-polymerase chain reaction (TSO-PCR). Patients were enrolled in a single-institution study comparing PBSC and bone marrow transplantation (BMT) for relapsed NHL. A molecular marker (CDR3 rearrangement, T cell beta receptor [TC beta R] rearrangement, or BCL-2/IgH rearrangement) was identified from analysis of the diagnostic tissue in 17 of 20 patients. Prior to undergoing BMT, 14 of 17 patients had PCR evidence of lymphoma involvement of either BM (11/17) or PBSCs (9/11). No decrease was found in the frequency of contamination of PBSCs compared with BM. In one patient, quantitative competitive PCR (C-PCR) identified a three- to tenfold greater quantity of contamination in the BM compared with PBSC. All evaluated patients (6/6) with contamination prior to BMT had persistence of marrow contamination following BMT. Our data demonstrate that TSO-PCR can generate a molecular marker for the majority of patients with intermediate- and high-grade NHL. In addition, we identified a high rate of occult lymphoma involvement in both BM and PBSC. As demonstrated by C-PCR, however, quantitative differences may exist in contamination of BM and PBSCs.

Base Sequence↗

PubMed1997

[Bacterial contamination of eyedrops in clinical use].

PURPOSE: The aim of this study is to assess the importance of bacterial contamination of multidose eyedrops in a routine clinical setting. MATERIAL AND METHODS: 406 eyedrop vials were cultured about one week after clinical use: 204 collected from an Ophthalmic Department, and 202 from a Nursing Home. The microbiological analysis was performed on the tip and the residual eyedrop, counting the number of bacterial colonies. RESULTS: 66 (16.3%) from the 406 analyzed vials were contaminated, and 5.4% out of these were severely affected. There was no significant difference between the "Ophthalmic Department" and the "Nursing Home". Commensal germs were the most frequently encountered in both groups. 4 gram negative organisms were isolated from the "Nursing Home" group. CONCLUSION: These results are in agreement with the literature. Comparison between our two groups is difficult because the eyedrops and uses were different. However, we notice the presence of gram negative organisms in the "Nursing Home". These severe contaminations due to opportunistic pathogen organisms are rare (0.75%), probably underestimated, and represent a real infectious risk during instillation. The study of the contamination site shows that the eyedrop is more often contaminated than the tip. This can be in relation to germ desicsation and to an aspiration phenomenon of contaminated fluid at the tip level. At last, the role of preservatives is not sufficient to ensure the sterility of multidose eyedrops during their use, and this justifies safer (single dose or filtration system) eyedrop vials.

Adult↗

PubMed1997

[Microbial contamination of small animal ambulatory veterinary clinics and waiting rooms].

Air and contact indicator microflora was monitored for a year during 17 outpatients' examinations at indicated sites of the balance loading area, examination tables and manipulation tables in an outpatients' consulting room partitioned into two sections (I, II) and in two waiting rooms (I, II) of an internal clinic of the Faculty of Veterinary Medicine at Brno. The consulting room and both waiting rooms were after reconstruction. Ambience monitoring by a sedimentation method demonstrated the lower microbial contamination of waiting room II and outpatients' consulting room II, which were reserved for vaccination of healthy animals. The ambience in waiting room I and outpatients' consulting room I, where diseased animals were examined, showed the higher values microbial contamination. The indicators of microbial contamination under observation involved total microbial counts on meat-peptone agar (MPA), counts of hemolytic (H+) and nonhemolytic (H+) micrococci on blood agar with 10% NaCl, counts of lactose positive (L+) and lactose negative (L-) microbes on Endo agar and of molds and other microbes on Czapek-Dox agar. Frequent occurrence of representatives of the genus Aspergillus and Penicillium out of 42 genera and species of identified molds was indicated in the ambience of the waiting rooms and outpatients' consulting rooms. Examination of the indicated sites of the balance loading area in waiting room I and of examination and manipulation tables in outpatients' consulting rooms by smear and impress methods demonstrated the lowest contamination on the surface of examination tables. Microbial contamination of the balance loading area was however highest, and the identified values indicate a risk of the permanent contact of animal patients with the increased microbe concentrations during their weighing. The balance location in the waiting room is not convenient under the present schedule of cleaning and cleansing. In the Discussion section, an overall decrease in the ambience microbial contamination in waiting rooms and outpatients' consulting room under observation in building no. 9 after reconstruction is shown in comparison with the results of preceding monitoring of the waiting room and outpatients' consulting room in building no. 6 under provisional conditions.

Animals↗

PubMed1997

Hospital preparedness for hazardous materials incidents and treatment of contaminated patients.

Hospital-based facilities providing emergency care in the state of Washington were surveyed to determine their level of preparedness for hazardous materials incidents including the treatment of contaminated patients. Responses to a faxed questionnaire were received from 95 (94%) of the 101 emergency care facilities in Washington State. Only 42 (44%) of the facilities reported the ability to receive any chemically exposed patient. Of the 95 responding emergency care facilities, 39 (41%) had no designated decontamination facilities; 67 (70%) had protocols for handling chemical contamination and possible evacuation from hazardous materials spills, and 52 (55%) had protocols for handling medical facility contamination and possible evacuation from treating chemically contaminated patients. Twelve (13%) facilities had evacuated their emergency department or other part of the hospital for contamination incidents in the past 5 years. Despite the frequent occurrence of hazardous materials incidents, most emergency care facilities in Washington State are not fully prepared to handle contaminated patients and chemical spills. This may have important implications for the care of persons with exposure to hazardous materials and for implementing Joint Commission on Accreditation of Healthcare Organizations standards and federal Occupational Safety and Health Administration regulations.

Accidents, Occupational↗

PubMed1998

[Effect of mycoplasma contamination of the human uterine leiomyosarcoma cell line SK-UT-1B on karyotype structure].

The karyotypic variability has been investigated for human uterine leiomyosarcoma cell line SK-UT-1B, cultivated for 30-90 days after contamination with Acholeplasma laidlawii, strain PG-8. The character of cell distribution for chromosome number gradually changes in contaminated cells, comparatively to the control, with the lengthening of the term of contamination. So, in 30 days the analysed distributions do not differ in the experimental and in the control variants, the modal number of chromosomes being equal to 46. In 60 days the frequency of cells with modal number of chromosomes have a tendency to decrease, and the range of variability in the number of chromosomes tend to increase. In 90 days, the frequency of cells with modal number of chromosomes decreases significantly, and the range of variability on the number of chromosomes increases significantly. The number of chromosomal aberrations gradually increases in contaminated cells, as compared to the control, with the lengthening of the term of contamination. So, in 30 days the number of chromosomal aberrations does not increase, only the number of dicentrics (telomeric associations) has the tendency to increase. In 60 days, the number of chromosomal aberrations, mainly dicentrics, increases significantly. In 90 days, the number of chromosomal aberrations increases significantly, including both dicentrics and chromatid breaks. The possible reasons of the observed character of karyotypic variability is discussed. Our previous results make it possible to suppose that the increase in the number of dicentrics in "markerless" line SK-UT-1B with long term contamination may be an additional evidence on the role of dicentrics in cell adaptation to in vitro conditions in such lines.

Acholeplasma laidlawii↗

PubMed1997

Contamination of soil with parasite eggs and oocysts in southern Thailand.

Soil contamination with parasite eggs and oocysts was surveyed in southern Thailand in December 1994 and September 1995. The survey areas were Hat Kai Tao Village in Phatthalung Province and a slum area in a city of Songkhla Province. We used a modification of the centrifugal floatation technique with sucrose solution (specific gravity, 1.200) to recover helminth eggs and protozoa oocysts. Overall, 10 genera and 11 species of parasite eggs and oocysts were recovered. They included eight species of nematoda eggs, one species of cestoda eggs, and two species of protozoan oocysts. The definitive hosts of these parasites are dogs, cats, sheep, lizards, humans, etc. The contamination rates in two areas at different occasions varied from 55% to 72% with an average of 64%. Contamination rates of Hat Kai Tao Village in beginning and end of the rainy seasons were 72%, and 55%, respectively. Although the contamination rate in the end of rainy season was higher than that in beginning of the rainy season, the difference was not statistically significant (p > 0.05). Of the 11 parasites recovered, six were infective to humans, of which, Trichuris trichura, Ascaris lumbricoides, and Toxocara species were predominant. The mean numbers of these eggs recovered in each test were more than 10. Therefore, the contamination was estimated to be more than an egg per gram of soil sample based on the recovery efficiency (40%) of this test. These results suggested that the soil in some parts of southern Thailand may be heavily contaminated by both animal and human feces.

Animals↗

PubMed1998

[Rapid progress of cirrhosis in hepatitis C: the role of age at the time of viral contamination].

OBJECTIVE: The aim of this study was to assess predictive factors for the progression to liver cirrhosis in hepatitis C. METHODS: One hundred thirty six patients (79 men; 57 women; mean age 39 years) with transfusion or intravenous drug use-associated hepatitis C virus (HCV) infection were studied. Sex, cause of infection, duration of contamination, and genotype were studied as predictive factors of progression to liver cirrhosis. RESULTS: One hundred twenty three patients presented with chronic hepatitis without cirrhosis and 13 had cirrhosis. At the time of liver biopsy, rates of cirrhosis were: 0% before 40 years, 10% between 40 and 60 years, and 47% after 60 years. (p < 0.05). Rates of cirrhosis according to the age at the time of contamination were as follows: 3% before 30 years; 16% between 30 and 50 years; 46% after 50 years even though duration of the disease was comparable in the three groups. In multivariate analysis, two independent factors were associated with liver cirrhosis: age at contamination and duration of infection. CONCLUSION: Duration of infection and especially age at contamination seem better correlated with the probability of cirrhosis than the route of transmission or the genotype 1b. The results of this study suggest that progression to cirrhosis is slower in cases of contamination before 30 years of age than later on. Age at the time of contamination is an important predictive factor of progression to cirrhosis.

Adolescent↗

PubMed1998

[Study of gastric emptying by dual isotopes. Corrections due to contamination].

The evaluation of gastric emptying by the double isotope technique involves some methodologic conditioning. Among them contamination correction or interference in the energy windows of the activity of the two isotopes used in the marking of the solids and fluids of the test food are important. The results of an experiment in which a phantom was used to evaluate the contamination between indio 111 (DTPA-Ca111In) and technecium 99m (colloid99mTc). Three test studies were posteriorly performed in healthy volunteers and 27 studies in a control group (13 males, mean age of 33 years, mean body mass index 39.02 kg/m). In these studies the contamination was corrected with the acquisition, following an initial swallow of juice marked with 111In, of activity in the windows of both isotopes. The contamination of 111In (isotope of greatest radiation energy) in the window of 99mTc was 24% in the phantom and 20%, 23% and 26% in the three initial study tests. The mean contamination in the control group was of 22% with limits of 19% to 29% and a standard deviation of 3%. Despite the comparable results, the usefulness of the individualized contamination calculation in the studies of gastric emptying with dual isotope to minimize the methodologic errors of this technique is discussed.

Adult↗

PubMed1987

Microbial contamination of contact lens care systems.

We examined the contact lens care systems of 100 asymptomatic patients who used hard or soft contact lenses for correction of refractive errors for the presence of bacteria, fungi, Acanthamoeba, and endotoxin. Of 100 patients, 52 had contaminated contact lens care systems. Sixteen of 126 bottles (13%) of commercial contact lens care solutions were contaminated. Contaminated commercial solutions were opened and used for a longer period of time than uncontaminated solutions. Contamination was not found in bottles of preserved commercial solutions that were opened and used for less than 21 days. All 12 bottles of homemade saline were contaminated with bacteria, and Acanthamoeba was isolated from two of these bottles. Pseudomonas was found in the care systems of 12 patients. Bacillus species, which form spores resistant to heat, were found in the care systems of seven patients. Endotoxin, which is also resistant to heat, was detected in nine of 35 care systems (26%) tested. Potential pathogens were isolated from the conjunctiva of six patients.

Adolescent↗

PubMed2026

A rare and atypical case of long-distance indirect DNA transfer: Contamination from an investigator never present at the scene.

To maximize the usefulness of DNA obtained from biological samples in forensic genetics, it is crucial to avoid DNA contamination throughout all procedures, from sample collection at crime scenes to STR profile generation in DNA laboratories. This study reports a rare and atypical case of DNA contamination in a forensic setting. During the analysis of biological evidence from a cold case preserved for 18 years, the STR profile obtained from the surface of a plastic bag matched that of an investigator, identified through the DNA elimination database. Case reconstruction confirmed that the investigator-who was located 80 km from the DNA laboratory and had never entered the crime scene or the sample storage room-was not a suspect and that the obtained STR profile originated from contamination. The most plausible explanation for the contamination was indirect transfer: investigator's DNA had adhered to a colleague's clothing and was subsequently dislodged and deposited onto the surface of the plastic bag as the colleague approached the sample pretreatment area. This study integrates trace DNA profiling of challenged samples with rapid contamination investigation and proposes prevention and control measures. This case underscores that, although DNA is widely regarded as the "gold standard" in forensic genetics, its interpretation must be considered within the context of the entire case. Conclusions should not be drawn based solely on a single DNA result.

Humans↗

PubMed2006

Isolation of Campylobacter spp. from a pig slaughterhouse and analysis of cross-contamination.

The purpose of this study was to establish the prevalence and possible contamination routes of Campylobacter spp. in a pig slaughterhouse. Swab samples were taken from the last part of rectum, from the carcasses surface before meat inspection and from slaughter line surface from 4 different pig herds during slaughtering. Identification of Campylobacter isolates was determined by the use of phase-contrast microscopy, hippurate hydrolysis, indoxyl acetate hydrolysis tests and PCR based restriction fragment length polymorphism method (PCR-RFLP). Pulsed-field gel electrophoresis (PFGE) typing using two macro-restriction enzymes SmaI and SalI was applied to in-slaughterhouse contamination analysis of pig carcasses. The study showed that 28 (63.6%) of the 44 samples collected at slaughterhouse were contaminated by Campylobacter spp. Up to 5 different colonies were obtained from each swab sample and a total of 120 different isolates were collected. 23.4% (28 of 120) isolates were identified as C. jejuni (19 from carcasses and 9 from slaughter line surfaces) and 76.6% (92 of 120) isolates as C. coli (28 from faeces, 47 from carcasses and 17 from slaughter line surfaces). The typing results showed identity between isolates from successive flocks, different carcasses, and places in the slaughterhouse in contact with carcasses. The results suggest that cross-contamination originated in the gastro-intestinal tract of the slaughtered pigs and that cross-contamination happened during the slaughter process.

Abattoirs↗

PubMed1991

Drug contamination from opening glass ampules.

Recently there have been several reports of postoperative sepsis due to the intravenous injection of contaminated solutions of propofol (Diprivan). The mechanism by which this contamination occurred has not been identified. This study sought to determine whether bacterial contamination of the contents of glass ampules can be decreased by swabbing the neck of the vial with alcohol prior to opening. Glass ampules of 1% propofol and 1% lidocaine were swabbed with a solution of Staphylococcus epidermidis. Half of these ampules were subsequently wiped with alcohol pads prior to being opened. An aliquot from each ampule was pipetted into a nutrient broth and allowed to incubate overnight at 37 degrees C. These solutions were plated on agar, incubated for 24 h, and then examined for bacterial growth. Three of the eight lidocaine ampules and six of the eight propofol ampules not cleaned with alcohol demonstrated evidence of bacterial contamination. The contents of all ampules that had been wiped with alcohol prior to being opened remained sterile (P less than 0.001 vs. non-alcohol-treated group for propofol ampules and P = 0.20 vs. non-alcohol-treated group for lidocaine ampules). These data suggest that bacterial contamination of propofol and lidocaine may occur as a result of opening glass ampules. Wiping the outside of the ampule with alcohol immediately prior to opening may decrease this risk.

Alcohols↗

PubMedDate not supplied

Trace element contamination of total parenteral nutrition. 2. Effect of storage duration and temperature.

BACKGROUND: Patients who receive home total parenteral nutrition (TPN) frequently are supplied with solutions up to 30 days in advance of anticipated use. The purpose of this study was to determine the stability of trace elements relative to time and temperature conditions, in a typical adult TPN solution stored in a usual home environment by examining variations in delivery of intended trace elements and inadvertent trace element contamination. METHODS: Trace element concentrations were determined using inductively coupled plasma-mass spectrometry technology. The effect of the delivery apparatus, storage duration (36 hours or 30 days) after compounding, and storage temperature (4 degrees C or 20 degrees C) were examined. RESULTS: The delivery apparatus contaminated the delivered TPN solution with cobalt but did not alter trace elements formulated into the TPN solution. Storage duration and temperature significantly decreased three (Zn, Cu, and Mn) of the six trace elements formulated into the TPN solution. Higher temperatures and longer duration of storage accelerated this decrease. Boron, Al, V, Ti, Ba, Sr, and CO were the trace elements that appeared as contaminants during storage. Boron, Al, V, and Ti contamination decreased with higher temperatures and longer duration of storage. CONCLUSIONS: Longer storage duration and higher storage temperature progressively reduced the deliverable concentrations of trace elements specifically formulated into the TPN solution and also of those trace elements that were not formulated into the TPN solution but that appeared as contaminants.

Drug Contamination↗

PubMed2006

An outbreak of Burkholderia cepacia associated with contamination of albuterol and nasal spray.

BACKGROUND: Species within the Burkholderia cepacia complex (Bcc) can contaminate medications and disinfectants and cause severe pneumonia in critically ill patients or persons with cystic fibrosis. In March 2004, we investigated a hospital outbreak of Bcc possibly associated with a contaminated nasal spray. METHODS: We conducted a matched case-control study, environmental sampling, and observations of infection control practices. Case patients had infection or colonization with Bcc, and control patients had sputum culture not yielding Bcc. Isolates from patients and environmental samples were compared by pulsed-field gel electrophoresis (PFGE). RESULTS: Bcc was recovered from sputum in 18 patients. Compared with matched control patients (n = 18), case patients were more likely to be receiving mechanical ventilation (p = 0.01), to have been hospitalized > 6 days (p = 0.01), and to have received antimicrobial treatment within 7 days before sputum collection (p = 0.03). Bcc was cultured from opened, but not unopened, multidose albuterol bottles, a nebulizer attached to a ventilator, and opened and unopened nasal spray bottles from contaminated lots. PFGE showed that isolates from albuterol samples and from patients were indistinguishable but unrelated to the nasal spray strain. Observations revealed improper aseptic techniques during respiratory therapy procedures and inadequate nebulizer cleaning. CONCLUSIONS: Despite a temporal association with use of a contaminated nasal spray, this outbreak was caused by extrinsic contamination of multidose albuterol used for nebulization treatments and lack of adherence to infection control precautions. Implementation and re-enforcement of infection control measures successfully terminated the outbreak.

Administration, Intranasal↗

PubMed2002

Transfer of persistent Listeria monocytogenes contamination between food-processing plants associated with a dicing machine.

The possibility of the transfer of persistent Listeria monocytogenes contamination from one plant to another with a dicing machine was evaluated, and possible reasons for persistent contamination were analyzed. A dicing machine that diced cooked meat products was transferred from plant A to plant B and then to plant C. After the transfer of the dicing machine, L. monocytogenes PFGE type I, originally found in plant A, was soon also found in plants B and C. This L. monocytogenes PFGE type I caused persistent contamination of the dicing lines in plants B and C. The persistent L. monocytogenes strain and three nonpersistent L. monocytogenes strains found in the dicing line of plant C were tested for adherence to stainless steel surfaces and minimal inhibitory concentrations of a quaternary ammonium compound and sodium hypochlorite, disinfectants widely used in the dicing lines. The persistent strain showed significantly higher adherence to stainless steel surfaces than did the nonpersistent strains. The minimal inhibitory concentrations of sodium hypochlorite were similar for all strains, and the minimal inhibitory concentrations of the quaternary ammonium compound for three of the L. monocytogenes PFGE types, including the persistent PFGE type, were high. All persistent L. monocytogenes PFGE type I isolates were found in an area with high hygienic standards, with the dicing machine being the first point of contamination. These observations show that the dicing machine sustained the contamination and suggest that the dicing machine transferred the persistent L. monocytogenes PFGE type from one plant to another.

Animals↗

PubMed2004

Longitudinal studies on Listeria in smoked fish plants: impact of intervention strategies on contamination patterns.

Four ready-to-eat smoked fish plants were monitored for 2 years to study Listeria contamination patterns and the impact of plant-specific Listeria control strategies, including employee training and targeted sanitation procedures, on Listeria contamination patterns. Samples from the processing plant environment and from raw and finished product were collected monthly and tested for Listeria spp. and Listeria monocytogenes. Before implementation of intervention strategies, 19.2% of raw product samples (n = 276), 8.7% of finished product samples (n = 275), and 26.1% of environmental samples (n = 617) tested positive for Listeria spp. During and after implementation of Listeria control strategies, 19.0% of raw product samples (n = 242), 7.0% of finished product samples (n = 244), and 19.5% of environmental samples (n = 527) were positive for Listeria spp. In one of the four fish plants (plant 4), no environmental samples were positive for L. monocytogenes, and this plant was thus excluded from statistical analyses. Based on data pooled from plants 1, 2, and 3, environmental Listeria spp. prevalence was significantly lower (P < 0.05) for nonfood contact surfaces and the finished product area and for the overall core environmental samples after implementation of control strategies. Listeria prevalence for floor drains was similar before and after implementation of controls (49.6 and 54.2%, respectively). Regression analysis revealed a significant positive relationship (P < 0.05) between L. monocytogenes prevalence in the environment and in finished products before implementation of control strategies; however, this relationship was absolved by implementation of Listeria control strategies. Molecular subtyping (EcoRI ribotyping) revealed that specific L. monocytogenes ribotypes persisted in three processing plants over time. These persistent ribotypes were responsible for all six finished product contamination events detected in plant 1. Ribotype data also indicated that incoming raw material is only rarely a direct source of finished product contamination. While these data indicate that plant-specific Listeria control strategies can reduce cross-contamination and prevalence of Listeria spp. and L. monocytogenes in the plant environment, elimination of persistent L. monocytogenes strains remains a considerable challenge.

Animals↗