Pre-surgical socket analysis for immediate implant placement.

BACKGROUND: Traditional protocols for implant surgery suggest a healing period of 2-3 months from dental extraction to implant placement. Based on all the volumetric modifications produced by that approach, there are authors who advocate for immediate implantology. The aim of the present study was to determine the prevalence of different sockets, and the dimensions of the bone around the upper anterior incisors and canines, to determine the predictability of immediate implants in our population. MATERIAL AND METHODS: This is an observational, cross-sectional study based on cone-beam computed tomography images of the anterior maxila of patients attending the Odontological Hospital of the University of Barcelona (OHUB) and requesting for implant treatment. Different measurements were performed on every analyzed tooth, and also they were categorized by using the main dental sockets classifications. RESULTS: Bone attachment levels and cortical thickness are lower in women compared to men in all three types of teeth (the difference in the bone attachment levels ranges from 4.68%-8.63% and in the bone thickness goes from 0.02-0.58mm). Bone attachment level gradually reduces with age. The reductions observed in all the measurements are higher in the case of canines, compared with the other teeth. The differences from patients <45 years old and patients between 55-64 years old are 13.58±14.55mm in the case of central incisors, 10.04±5.52 in the case of lateral incisors and 22.39±13.65mm in the case of canines. CONCLUSIONS: According to our results, the canines are the teeth with the greatest complexity when it comes to immediate implantology treatments. Furthermore, that kind of treatment is more complex as age increases, since we observed a gradual percentage of unfavourable sockets in older patients.

Spontaneously Arising Canine Glioma as a Potential Model for Human Glioma.

Human gliomas are malignant brain tumours that carry a poor prognosis and are composed of a heterogeneous population of cells. There is a paucity of animal models available for study of these tumours and most have been created by genetic modification. Spontaneously arising canine gliomas may provide a model for the characterization of the human tumours. The present study shows that canine gliomas form a range of immunohistochemical patterns that are similar to those described for human gliomas. The in-vitro sphere assay was used to analyze the expansion and differentiation potential of glioma cells taken from the periphery and centre of canine tumours. Samples from the subventricular zone (SVZ) and contralateral parenchyma were used as positive and negative controls, respectively. The expansion potential for all of these samples was low and cells from only three cultures were expanded for six passages. These three cultures were derived from high-grade gliomas and the cells had been cryopreserved. Most of the cells obtained from the centre of the tumours formed spheres and were expanded, in contrast to samples taken from the periphery of the tumours. Spheres were also formed and expanded from two areas of apparently unaffected brain parenchyma. The neurogenic SVZ contralateral samples also contained progenitor proliferating cells, since all of them were expanded for three to five passages. Differentiation analysis showed that all cultured spheres were multipotential and able to differentiate towards both neurons and glial cells. Spontaneously arising canine gliomas might therefore constitute an animal model for further characterization of these tumours.

[Effectiveness and safety of goal directed nurse-led blood glucose control in an intensive care unit: a prospective observational study]. / Eficacia y seguridad del control de glucemia guiado por objetivo y dirigido por el personal de enfermería en una unidad de cuidados intensivos: un estudio prospectivo observacional.

OBJECTIVE: to evaluate the effectiveness and safety of a nurse-led blood glucose control protocol in a medical ICU. METHOD: a descriptive, prospective study was carried out for a period of 13 months. All blood glucose values from patients on insulin therapy for intensive glycemic control were recorded daily. RESULTS: A total of 12,677 blood glucose determinations were performed on the 69 patients under glycemic control; 57.9% of the determinations had predetermined study target values for blood glucose (100-140 mg/dl) and 68.8% of the determinations had physiological blood glucose values (80-140 mg/dl); no values under 40 mg/dl were obtained, and only 0.2% were between 40-60 mg/dl. CONCLUSIONS: For an adequate blood glucose control using intensive insulin therapy, individual management of insulin infusion regimen is essential, adjusted to the characteristics of each patient. A nurse-led intervention has allowed better results to be obtained in comparison with other studies in which different protocols for insulin infusion are used.

Antimicrobial activity and occurrence of bacteriocin structural genes in Enterococcus spp. of human and animal origin isolated in Portugal.

The main objective of this study was to detect the antimicrobial activity and the presence of bacteriocin structural genes in 224 enterococcal isolates from fecal origin obtained from humans, pets, wild animals and birds. Direct antimicrobial activity against Listeria monocytogenes CECT4032 was detected in 102 (45.6%) of the tested isolates. From these, only 22 displayed bacteriocin activity against this indicator. The bacteriocinogenic strains contained one or more of the bacteriocin structural genes tested in this study, with those of enterocins P, A and L50 (L50A and L50B) being the most abundant. Our results show a high occurrence of the combination of different bacteriocin structural genes in the enterococcal isolates analyzed, indicating an elevated genetic potential of these strains to produce various bacteriocins.

[Prevalence of antiretroviral drug genotypic resistance among HIV patients in Cuenca, Spain]. / Prevalencia de la resistencia genotípica a los fármacos antirretrovirales en pacientes VIH positivos en la provincia de Cuenca.

The aims were to assess the prevalence of resistances to antiretroviral drugs in HIV patients in the province of Cuenca and to determine the most frequently detected primary resistances. A total of 79 samples collected from April 2000 to July 2004 were analyzed. Resistance was detected using the genotypic technique VERSANTTM HIV1 (LiPA). Mutations more frequently found were M184V in the reverse transcriptase gene and V82A in the protease gene. The prevalence of primary resistances was 39.4%. Mutations more frequently detected were similar to those reported by other authors. The rate of primary resistance was higher than those found by other authors in Spain.

Antimicrobial and safety aspects, and biotechnological potential of bacteriocinogenic enterococci isolated from mallard ducks (Anas platyrhynchos).

Samples from the intestinal content and carcasses of mallard ducks (Anas platyrhynchos) were evaluated for enterococci with antimicrobial activity, presence of genes coding bacteriocins and their expression, and potential virulence factors. Enterococcus faecalis comprised the largest enterococcal species with antagonistic activity followed by E. faecium, E. hirae, Enterococcus spp., and the non-enterococci. Although all E. faecalis isolates manifested a potent direct antimicrobial activity, no activity was detected in supernatants of most producer cultures. However, all E. faecium isolates showed antimicrobial activity in their supernatants and encoded bacteriocins, although the occurrence in the isolates of several enterocin genes did not always correlate with a higher antagonistic activity in supernatants. The efaAfm determinant was the only virulence gene detected in E. faecium, while E. faecalis showed a larger number of virulence determinants, and E. hirae did not carry any of the virulence genes examined. The rapid identification of genes coding described bacteriocins permits recognition of isolates that are potentially producers of novel bacteriocins. Purification of the antimicrobial activity of E. hirae DCH5 and Lactococcus garvieae DCC43 revealed unique chromatographic fragments after MALDI-TOF mass spectrometry analysis, suggesting the antagonistic peptides were purified to homogeneity. Bacteriocinogenic E. faecium and E. hirae isolates may be considered hygienic for production of bacteriocins, and potentially safe due to their low incidence of potential virulence genes and susceptibility to most clinically relevant antibiotics. However, the presence among the enterococci of E. faecalis strains with a potent antagonistic activity and multiple virulence factors, raises concerns regarding their potential pathogenicity to consumers.

Cloning, production and functional expression of enterocin P, a sec-dependent bacteriocin produced by Enterococcus faecium P13, in Escherichia coli.

The cloning and expression of enterocin P (EntP), a sec-dependent bacteriocin produced by Enterococcus faecium P13, was studied in Escherichia coli. PCR-amplified products of the preenterocin P gene (entP) or entP plus the putative EntP immunity gene (entiP), were cloned in plasmid pETBlue-1 under the control of the inducible T7lac promoter. Although target genes in derivative plasmids pJG01 (entP) and pJG02 (entP plus entiP) did not generate products with antimicrobial activity after an in vitro combined transcription/translation reaction, they were expressed as biologically active products following transformation and induction in the E. coli Tuner(DE3)pLacI host. The use of specific antibodies and an ELISA permitted the detection and quantification of EntP in the supernatant (SN), cellular soluble protein fraction (CSF), and inclusion bodies (IB) of E. coli Tuner(DE3)pLacI cells transformed with either pJG01 or pJG02. Functional EntP from the supernatants of E. coli Tuner(DE3)pLacI (pJG01) cultures grown in a complex medium was recovered, at a high efficiency, by immunoaffinity chromatography in a single step. A purification method based on hydrophobic adsorption and reverse-phase chromatographies also permitted the recovery of active EntP from the supernatants of the same cultures grown in a minimally defined medium. The E. coli Tuner(DE3)pLacI (pJG01) cells would merit consideration as an alternative experimental model for the heterologous production and functional expression of EntP, as well as for the fast and efficient recovery of this bacteriocin from the supernatant of this recombinant producer.

[Levofloxacin versus beta-lactamic therapy in community acquired pneumonia that requires hospitalization]. / Levofloxacino frente a betalactámicos en el tratamiento de la neumonía adquirida en la comunidad con ingreso hospitalario.

OBJECTIVE: To compare the effectiveness and security of levofloxacin treatment in front betalactamic therapy in patient with community-acquired pneumonia that require hospitalization (CAPH). PATIENT AND METHODS: A prospective and randomized study along a year from 49 patients diagnosed of (CAPH) that were admitted in the Internal Medicine Service. The patients were assigned randomly to receive.-I: cefotaxime or ceftriaxone, II: amoxicillin/clavulanate (both could be associated or not with a macrolide) or III: levofloxacin. It was accomplished Rx. thorax to 7-10 days, to the month and, other reviews if was necessary. RESULTS: 29 cases were in standard therapy (I or II) and 20 cases received levofloxacin therapy. Male 84%, half age 70.9 years old, 57% with moderate or severe underlying disease, and 55% with approaches of initial severity criteria. In 47% of the cases we arrived to etiologic diagnosis, in the third of the cases were BGN. The cure took place in 94% of the patients and 2 patients died (5%). No differences were observed regarding demographic characteristics, underlying disease and severity. No differences were detected in: the secondary effects, complications, hospital stay or, mean stay or percentage of cures. The necessity to prolong the therapy was bigger in the standard group in front of the group tried with levofloxacin (52% vs. 15%, p:0.02). CONCLUSIONS: In bigger population and with initial severity the treatment with levofloxacin can be a valid alternative to the standard therapy.

[Tularemia outbreak in the province of Cuenca associated with crab handling]. / Brote epidémico de tularemia en la provincia de Cuenca en relación con la manipulación de cangrejos.

OBJECTIVE: To report the clinical and epidemiologic characteristics of 19 patients diagnosed of tularemia at our hospital following an epidemic outbreak occurred in our health area. METHODS: Retrospective analysis of clinical records of patients admitted to our hospital who were examined at the Infectious Diseases Clinic and had clinical findings and epidemiologic data consistent with tularemia during the period from June 1998 to March 1999. CASE DEFINITION: A patient was considered to fulfill the case definition when clinical symptoms, epidemiologic data and the following laboratory criteria were met: antibody titer to Francisella tularensis (tube agglutination test) > or = 1/128 in the convalescence serum specimen, seroconversion or recovery of the microorganism from biological material. RESULTS: Nineteen patients with a median age of 60 years. Males predominated (63.1% male patients); all of them had handled red crayfish from the same source (río Mayor). The incubation period ranged from 0 to 15 days (mean 4.88 days). All patients presented with the ulceroglandular form. Seventy-three percent of patients received doxycycline. Only one patient relapsed. Water samples from the reservoir of the depuration plant of the river were positive to F. tularensis by PCR. This same result was confirmed in stomach and hepatopancreas of crayfish fished in río Mayor in the second half of July. CONCLUSIONS: The most likely hypothesis of this outbreak was the contamination of the river water with animals dead from tularemia which, together with the characteristics of the transmission mechanism (wounds caused by crabs) had contributed to the acquisition of this disease in humans. Interestingly too, red crayfish as the source of infection.

Optimization of enterocin P production by batch fermentation of Enterococcus faecium P13 at constant pH.

The influence of pH on growth, enterocin P production and glucose consumption by Enterococcus faecium P13 was studied during anaerobic batch fermentation in MRS broth at 32 degrees C in a fermentor. Growth and glucose consumption were maximal at pH 7.0. Enterocin P production displayed primary metabolite kinetics and was strongly dependent on pH. A maximum antimicrobial activity of 1,949 bacteriocin units (BU) ml(-1) was obtained at pH 6.0, which represented a four-fold increase compared with the antimicrobial activity obtained without pH regulation. The pH exerted a marked effect on the decrease in bacteriocin activity, with the decrease being maximal at pH 7.0. In this report, we propose models for the growth of E. faecium P13 as well as enterocin P production and inactivation. Enterocin P production decreased when potentially stress-inducing compounds (NaCl or ethanol) were included in the growth medium.

Pulmonary fibrosis induced by cyclophosphamide.

OBJECTIVE: To report a case of pulmonary fibrosis resulting from use of cyclophosphamide as chemotherapy to treat a patient with breast cancer. CASE SUMMARY: We describe the case of a 52-year-old woman with breast cancer who developed pulmonary fibrosis after four cycles of chemotherapy that included cyclophosphamide. Pulmonary function tests revealed the presence of a severe ventilatory restriction. The open lung biopsy revealed pulmonary fibrosis with vascular sclerosis and signs of pulmonary hypertension. DISCUSSION: Cyclophosphamide is an alkylating agent that has been associated with interstitial pneumonia and pulmonary fibrosis. The frequency of these unwanted effects is <1%. The clinical picture consists of the progressive appearance of dyspnea and a non-productive cough that progresses to severe pulmonary insufficiency. The risk factors described for these complications have been the use of chemotherapy regimens that include other drugs with known pulmonary toxicities, the cumulative total dose, the addition of radiotherapy, and the use of high doses of cyclophosphamide. CONCLUSIONS: Even though the frequency of pulmonary fibrosis in patients treated with cyclophosphamide-based chemotherapy regimens is low, the presence of dyspnea and an interstitial pattern in a patient makes it necessary to consider that possible drug toxicity. The open lung biopsy is the most accurate diagnostic technique for these cases. The discontinuation of cyclophosphamide and treatment with corticosteroids is usually followed by clinical recovery in approximately 50% of patients and, in some cases, reversal of the lung injury.

Enterocin P selectively dissipates the membrane potential of Enterococcus faecium T136.

Enterocin P is a pediocin-like, broad-spectrum bacteriocin which displays a strong inhibitory activity against Listeria monocytogenes. The bacteriocin was purified from the culture supernatant of Enterococcus faecium P13, and its molecular mechanism of action against the sensitive strain E. faecium T136 was evaluated. Although enterocin P caused significant reduction of the membrane potential (DeltaPsi) and the intracellular ATP pool of the indicator organism, the pH gradient (DeltapH) component of the proton motive force (Deltap) was not dissipated. By contrast, enterocin P caused carboxyfluorescein efflux from E. faecium T136-derived liposomes.

Short-term follow-up results in 795 nonpalpable probably benign lesions detected at screening mammography.

PURPOSE: To evaluate short-term follow-up of nonpalpable probably benign lesions in a 2-year mammographic screening. MATERIALS AND METHODS: Of 13,790 women aged 45-65 years who underwent first-round screening, 795 (5.8%) underwent short-term mammographic follow-up (every 6 months for 2 years) of nonpalpable probably benign lesions (eg, masses, focal asymmetric densities, and calcifications) previously assessed at an additional imaging evaluation, including ultrasonography. When no changes were found at short-term mammographic follow-up, women were assigned to the 2-year screening interval. Needle localization and surgical biopsy were performed when the lesion progressed (was enlarged or had an increased number or size of calcifications or modification of their initial characteristics). The effectiveness of this approach was evaluated with statistical analysis. RESULTS: Of 795 lesions, 788 (99%) remained stable, and seven (1%) had changes prompting surgical biopsy. Two cancers (0.3%), one microinvasive intraductal carcinoma and one 7-mm invasive ductal carcinoma without positive nodes, were found. Four of the five benign histologic results were probably benign calcifications with progression at short-term follow-up. The sensitivity, specificity, accuracy, and positive and negative predictive values were 100%, 99%, 99%, 29%, and 100%, respectively. CONCLUSION: The benign nature of most nonpalpable probably benign lesions can be typified with short-term mammographic follow-up. This approach permitted identification of a few low-stage carcinomas, but progression in the probably benign calcifications was usually unrelated to malignancy.

Enterocin P causes potassium ion efflux from Enterococcus faecium T136 cells.

Enterocin P is a bacteriocin produced by Enterococcus faecium P13. We studied the mechanism of its bactericidal action using enterocin-P-sensitive E. faecium T136 cells. The bacteriocin is incapable of dissipating the transmembrane pH gradient. On the other hand, depending on the buffer used, enterocin P dissipates the transmembrane potential. Enterocin P efficiently elicits efflux of potassium ions, but not of intracellularly accumulated anions like phosphate and glutamate. Taken together, these data demonstrate that enterocin P forms specific, potassium ion-conducting pores in the cytoplasmic membrane of target cells.

Biochemical and genetic evidence that Enterococcus faecium L50 produces enterocins L50A and L50B, the sec-dependent enterocin P, and a novel bacteriocin secreted without an N-terminal extension termed enterocin Q.

Enterococcus faecium L50 grown at 16 to 32 degrees C produces enterocin L50 (EntL50), consisting of EntL50A and EntL50B, two unmodified non-pediocin-like peptides synthesized without an N-terminal leader sequence or signal peptide. However, the bacteriocin activity found in the cell-free culture supernatants following growth at higher temperatures (37 to 47 degrees C) is not due to EntL50. A purification procedure including cation-exchange, hydrophobic interaction, and reverse-phase liquid chromatography has shown that the antimicrobial activity is due to two different bacteriocins. Amino acid sequences obtained by Edman degradation and DNA sequencing analyses revealed that one is identical to the sec-dependent pediocin-like enterocin P produced by E. faecium P13 (L. M. Cintas, P. Casaus, L. S. Hâvarstein, P. E. Hernández, and I. F. Nes, Appl. Environ. Microbiol. 63:4321-4330, 1997) and the other is a novel unmodified non-pediocin-like bacteriocin termed enterocin Q (EntQ), with a molecular mass of 3,980. DNA sequencing analysis of a 963-bp region of E. faecium L50 containing the enterocin P structural gene (entP) and the putative immunity protein gene (entiP) reveals a genetic organization identical to that previously found in E. faecium P13. DNA sequencing analysis of a 1,448-bp region identified two consecutive but diverging open reading frames (ORFs) of which one, termed entQ, encodes a 34-amino-acid protein whose deduced amino acid sequence was identical to that obtained for EntQ by amino acid sequencing, showing that EntQ, similarly to EntL50A and EntL50B, is synthesized without an N-terminal leader sequence or signal peptide. The second ORF, termed orf2, was located immediately upstream of and in opposite orientation to entQ and encodes a putative immunity protein composed of 221 amino acids. Bacteriocin production by E. faecium L50 showed that EntP and EntQ are produced in the temperature range from 16 to 47 degrees C and maximally detected at 47 and 37 to 47 degrees C, respectively, while EntL50A and EntL50B are maximally synthesized at 16 to 25 degrees C and are not detected at 37 degrees C or above.

Cancer mortality and exposure to chemical carcinogens in the work place: an ecological study in the Valencian Community, Spain (1981-1995).

To evaluate the geographical distribution of the mortality from malignant tumours in relationship with exposure to chemical carcinogens in the work place, and to asses the possible association between these questions and the percentage of population employed in certain high-risk sectors, an ecological study in the Valencian Community (VC), Spain was carried out. Age-adjusted mortality rates for the total number of malignant tumours, lung, bladder, lymphomas and leukaemia during the periods 1981-1985 and 1991-1995 were calculated for the 34 geographical areas. The percentage of population in each area working in sectors in which they may be exposed to chemical carcinogens was obtained. The relationship between mortality on-the-job exposure was studied using linear regression methods. Large differences in cancer mortality were seen. In men, the geographical pattern was very stable and reveals a significant association with the distribution of certain high-risk jobs. Statistically significant positive correlations (p < 0.001) were found between cancer mortality and the percentage of the population working in metal, wood and furniture sectors. In contrast, a negative and statistically significant (p < 0.001) correlation was observed between cancer mortality and the percentage of the population working in agriculture. In conclusion, although the variability in cancer mortality in men was significantly associated with some occupational sectors in the VC, caution is needed when drawing conclusions about causation from ecological studies.

Antibodies to a synthetic 1-9-N-terminal amino acid fragment of mature pediocin PA-1: sensitivity and specificity for pediocin PA-1 and cross-reactivity against Class IIa bacteriocins.

Polyclonal antibodies specific for pediocin PA-1 (PedA1) were generated by immunization of rabbits with a chemically synthesized 1-9-N-terminal amino acid fragment of this bacteriocin (PH1) conjugated to the carrier protein keyhole limpet haemocyanin (KLH). The PH1 fragment holds a highly conserved amino acid sequence with closely related Class IIa bacteriocins. The sensitivity and specificity of the PH1-KLH-generated rabbit polyclonal antibodies were evaluated by the development of various ELISAs, such as a non-competitive indirect ELISA (NCI-ELISA), a competitive indirect ELISA (CI-ELISA), a competitive direct ELISA (CD-ELISA) and a sandwich ELISA (S-ELISA), and by protein slot-blotting and Western blotting. NCI- and CI-ELISA were valuable for detecting the existence of PedA1-specific antibodies in the sera of immunized rabbits. The limit of detection of PedA1 in MRS medium was found to be 0.5 microg ml(-1) in NCI-ELISA, while CI-ELISA on plates coated with purified PedA1 increased the affinity of the PH1-KLH-generated antibodies for PedA1; the limit of detection of PedA1 was less than 0.01 microg ml(-1) and 50% binding inhibition was achieved with 0.1 microg PedA1 ml(-1). Similarly, the limits of detection of PedA1 in MRS medium were found to be 5 microg ml(-1) by protein slot-blotting and 0.01 microg ml(-1) by Western blotting. Most importantly, PH1-KLH-generated polyclonal antibodies detected the presence of PedA1 in the supernatants of the producing strains of Pediococcus acidilactici 347, Z102, A172, X13 and P20, with no reactivity or negligible immunoreactivity with the supernatants of other lactic acid bacteria producing or not producing closely related or different bacteriocins. The approaches taken for the selection of the bacteriocin peptide fragment, the generation of antibodies and the development of immunoassays could prove useful for the generation and evaluation of antibodies of adequate specificity for other bacteriocins of interest in the food industry.

Biochemical and genetic evidence of enterocin P production by two Enterococcus faecium-like strains isolated from fermented sausages.

Two bacteriocin-producing Enterococcus faecium-like strains were independently isolated from fermented sausages. Bacteriocins were purified to homogeneity by ammonium sulfate precipitation, gel filtration, cationic exchange, hydrophobic interaction, and reverse-phase liquid chromatography. Two peptide inhibitory fractions were purified from each strain, denominated A and B for E. faecium AA13, and C and D for E. faecium G16. Fraction B was blocked for amino acid sequencing by Edman degradation, while the amino acid sequences obtained from peptides A, C, and D contained the YGNGV consensus motif in positions 5 to 9, and the ATRS sequence in positions 1 to 4. By use of PCR techniques and nucleotide sequencing, the structural gene of enterocin P was found both in E. faecium AA13 and E. faecium G16. Metabolic and genetic features of the two strains suggest that they are slightly different, they may produce more than one bacteriocin, and both produce enterocin P.

[The risk-benefit of the treatment of tuberculosis with a high bacilloscopy sensitivity in a provincial hospital]. / Riesgo-beneficio del tratamiento de tuberculosis, en un hospital provincial, con una sensibilidad alta de la baciloscopia.

BACKGROUND: To know the incidence and type of hepatic toxicity (HTX) of the tuberculous chemotherapy and to value the risk-benefit of treatment in our elderly population in a high sensibility context of the bacilloscopy. PATIENTS AND METHODS: Prospective study of 161 tuberculous patients with standards of 6 months, from January 1989 to December 1994. 75 patients with (INH, FR, PZ and ETB) and 83 patients with (INH, RF and PZ). It was accomplished clinical, analytical and microbiological control to all the patients during 24 months. RESULTS: 28% of the patients had more than 65 years and a 26% HIV infection. The tuberculosis (TBC) was disseminated in a 41%. A 74% of the patients ha positive bacilloscopy. The therapeutic fulfillment was correct in a 85% of the cases. A 48% of HTX was observed, with a 9% of serious HTX (associated with alcoholism and age greater tan 60 years). In 14% of he patients was changed in a way definitive the therapeutic standard. There was a 17% of therapeutic failure (associated with disseminated TBC and HIV infection) and a 7% of relapses. The attributive mortality of TBC was of a 4%. CONCLUSIONS: The transient and moderate increase in transaminase activity is frequent and it does not require to modify the chemotherapy. In the greater patients of 65 years the benefit of trying outweigh the risk, if is accomplished a narrow follow-up with precocious suspension of the drugs in the event of serious toxicity.

Generation of polyclonal antibodies of predetermined specificity against pediocin PA-1.

Polyclonal antibodies of predetermined specificity for pediocin PA-1 (pedA1) have been generated by immunization of rabbits with a chemically synthesized C-terminal fragment of this bacteriocin (PH2) conjugated to the carrier protein keyhole limpet hemocyanin (KLH). The sensitivity and specificity of the PH2-KLH-generated antibodies were evaluated by the development of various enzyme-linked immunosorbent assays (ELISAs)-a noncompetitive indirect ELISA (NCI-ELISA), a competitive indirect ELISA (CI-ELISA), and a competitive direct ELISA (CD-ELISA)-and by immunodotting. All immunoassays indicated the existence of pedA1-specific antibodies with high relative affinities and adequate sensitivities in the sera of immunized animals. The limits of detection of pedA1 in MRS medium (Oxoid Ltd., Basingstoke, United Kingdom) were found to be 2.5 microg/ml by immunodotting and 1 microg/ml in the NCI-ELISA. However, the CI-ELISA enhanced the limit of detection of pedA1 to 0.025 microg/ml, while the amount of free pedA1 required for 50% binding inhibition was 10 microg/ml. Moreover, the CD-ELISA increased the affinity of the PH2-KLH-generated antibodies for pedA1; the limit of detection of pedA1 was less than 0.025 microg/ml, and the 50% binding inhibition value was reduced to 0.5 microg of pedA1/ml. All immunoassays and the slot dot assay detected the presence of pedA1 in the supernatant of the producing strain Pediococcus acidilactici 347, with no reactivity or negligible immunoreactivity with the supernatants of other lactic acid bacteria producing or not producing different bacteriocins. The approaches taken for the generation of antibodies and the development of immunoassays could prove useful for the generation and evaluation of antibodies of predetermined specificity for other bacteriocins of interest in the food industry.