Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella spp. in free-ranging waterfowl from Entre Rios, Argentina.

The present study was conducted to estimate the apparent prevalence of Salmonella spp. in free-ranging waterfowl that inhabitant Entre Ríos, Argentina, determine the antimicrobial resistance of the isolated, and compare the performance of two selective plating media used for Salmonella isolation. Five hundred ninety nine free-living waterfowl were sampled one time by cloacal swab from April 2014 to July 2016. Only 6 samples from waterfowl belonged to all counties sampled were positive to Salmonella spp., so the apparent prevalence was 1%. Four serovars were isolated (Salmonella ser. Typhimurium, S. ser. Schwarzengrund, S. enterica subsp. I [4,12: i: -], S. enterica subsp. IIIb [60: r: e, n, x, z15]), which were susceptible to 15 antibiotics tested and resistant to erythromycin. Furthermore, some strains showed an intermediate resistant to neomycin, ciprofloxacin and/or streptomycin. The multiple antibiotic resistances index was 0.05. For Hektoen enteric agar and Salmonella Shigella agar, the relative accuracy, sensitivity, specificity, positive predictive value, and negative predictive value did not show any difference between them. The agreement was good between these two plating-media and the difference between these plating-media was not statistically significant. The low prevalence of Salmonella spp. in waterfowl in Entre Rios should not be discounted, since Salmonella ser. Typhimurium was the most prevalent serovar and some free-ranging waterfowl species studied can migrate from/to different countries, increasing the possibility to cross-contaminated Salmonella to resident or other migrant birds.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella in backyard chickens from Entre Rios, Argentina.

This study was conducted to estimate the apparent prevalence of Salmonella spp. in birds kept under backyard system in Entre Ríos, Argentina, and determine the performance of two selective plating media used for Salmonella isolation, and the antimicrobial resistance of the isolated. Also, the association of farms characteristics with Salmonella presence was evaluated. A total of 657 backyard chickens and 15 gooses were sampled one time by cloacal swab, belonging to 51 and one family farms, respectively, and four counties in Entre Rios state from April 2014 to May 2015. Only four samples from backyard chickens belonged to three family farms from Uruguay County were positive to Salmonella spp., so the apparent prevalence was 0.6% for this kind of chicken. Four serovars were isolated (Salmonella ser. Lille, S. ser. Newport, S. ser. Enteritidis and S. ser. Rissen), which were susceptible to all antibiotics tested with the exception of erythromycin. For Hektoen enteric agar and brilliant green agar, relative specificity and positive predictive value were 1, and the relative sensitivity and negative predictive value did not show any difference between them. The agreement was very good between these two plating media. None of the variables studied could be selected to calculate the risk factors associated with Salmonella isolation because p > .15. Although the prevalence of Salmonella spp. is low in backyard birds in Entre Rios, the presence of S. ser. Enteritidis should not be discounted, because it is found in the county that concentrates a large population of intensive poultry production in the state.

Salmonella spp. contamination in commercial layer hen farms using different types of samples and detection methods.

The performance of detection methods (culture methods and polymerase chain reaction assay) and plating media used in the same type of samples were determined as well as the specificity of PCR primers to detected Salmonella spp. contamination in layer hen farms. Also, the association of farm characteristics with Salmonella presence was evaluated. Environmental samples (feces, feed, drinking water, air, boot-swabs) and eggs were taken from 40 layer hen houses. Salmonella spp. was most detected in boot-swabs taken around the houses (30% and 35% by isolation and PCR, respectively) follow by fecal samples (15.2% and 13.6% by isolation and PCR, respectively). Eggs, drinking water, and air samples were negative for Salmonella detection. Salmonella Schwarzengrund and S. Enteritidis were the most isolated serotypes. For plating media, relative specificity was 1, and the relative sensitivity was greater for EF-18 agar than XLDT agar in feed and fecal samples. However, relative sensitivity was greater in XLDT agar than EF-18 agar for boot-swab samples. Agreement was between fair to good depending on the sample, and it was good between isolation and PCR (feces and boot-swabs), without agreement for feed samples. Salmonella spp. PCR was positive for all strains, while S. Typhimurium PCR was negative. Salmonella Enteritidis PCR used was not specific. Based in the multiple logistic regression analyses, categorization by counties was significant for Salmonella spp. presence (P-value = 0.010). This study shows the importance of considering different types of samples, plating media and detection methods during a Salmonella spp. monitoring study. In addition, it is important to incorporate the sampling of floors around the layer hen houses to learn if biosecurity measures should be strengthened to minimize the entry and spread of Salmonella in the houses. Also, the performance of some PCR methods and S. Enteritidis PCR should be improved, and biosecurity measures in hen farms must be reinforced in the region of more concentrated layer hen houses to reduce the probability of Salmonella spp. presence.

A comparative study of culture methods and PCR assay for Salmonella detection in poultry drinking water.

The present work compared 2 culture methods and PCR assays for motile and nonmotile Salmonella detection using artificially contaminated poultry drinking water. The specificity was 1 for all methods studied. The accuracy and sensitivity were 1 for all motile strains, whereas these parameters were between 0 and 0.7 for nonmotile Salmonella strains. The positive predictive value and negative predictive value were 1 for all motile Salmonella strains in the 3 methods used. Nonmotile Salmonella strains showed a positive predictive value of 1 in the PCR method. However, the positive predictive value was indeterminate in the tetrathionate (TT) methods for both strains tested and in the modified semisolid Rappaport-Vassiliadis (MSRV) method for Salmonella Pullorum. On the other hand, the negative predictive value was between 0.20 and 0.43 for the 3 methods. The detection level of motile strains was 4 to 7 cfu/25 mL for all methods. Nonmotile Salmonella strains could not be detected in the TT method, whereas only Salmonella Gallinarum could be recovered from 1.1 × 10(1) cfu/25 mL in the MSRV method. In relation to the molecular methods, PCR could detect these strains from 1.1 × 10(4) cfu/25 mL. Extending incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. The kappa coefficient showed that there was an excellent agreement between the 3 methods for motile strains. For nonmotile strains, the agreement was poor between the MSRV and the PCR; there was no agreement when the TT method was compared with the MSRV and the PCR methods. The difference in detection levels obtained with the methods used for motile and nonmotile Salmonella strains and the difficulty in detecting these last strains represents a potential problem when a poultry water sample is considered negative for the presence of Salmonella.

A comparative study of culture methods and polymerase chain reaction for Salmonella detection in egg content.

The present work compared 2 culture methods and a PCR assay applied with 2 enrichment methods for the detection of motile and nonmotile Salmonella strains using artificially contaminated egg content. The specificity (Sp) was 1 in all methods. The sensitivity (Se), accuracy (Ac), positive predictive value (PPV), and negative predictive value (NPV) were 1 in both culture methods for motile and nonmotile strains. In reference to the PCR methods, Se and PPV were between 0 and 1, whereas Ac and NPV were between 0.14 and 1. The detection level of motile and nonmotile strains was 5 to 54 cfu per 25 mL for both culture methods, but some strains could not be detected by the PCR methods. Extending incubation time of the enrichment medium to 5 d in the tetrathionate broth (TT), and Muller-Kauffmann tetrathionate-novobiocin broth (MKTTn) methods did not improve the isolation rates. All selective plating media did not show any statistical differences in the parameters of performance studied. Kappa coefficients showed that there was an excellent agreement between the bacteriological methods for all Salmonella strains. The agreement was very good and good between the PCR methods, for motile and nonmotile strains, respectively. However, there was a poor agreement when the PCR and bacteriological methods were compared for motile and nonmotile Salmonella strains. The TT and MKTTn methods are similar in terms of Ac, Se, Sp, PPV, and NPV for different Salmonella strains in egg content. The use of the PCR method cannot improve the same parameters, described before, in this matrix. So, further studies are needed to improve the performance parameters and limit of detection in egg content for the PCR methods, so that test can be used in poultry and food industry.

Comparison of 2 culture methods and PCR assays for Salmonella detection in poultry feces.

The present work compared 2 culture methods and the combinations of pre-enrichment and enrichment culture methods with PCR assays [buffered peptone water-PCR and tetrathionate-PCR or modified semisolid Rappaport-Vassiliadis (MSRV)-PCR] for motile and nonmotile Salmonella strain detection using artificially contaminated poultry feces. The specificity and positive predictive values were equal to one in both culture methods. Specificity and positive predictive values, accuracy, sensitivity, and negative predictive values were higher for motile than nonmotile Salmonella strains in culture methods. Only Salmonella enterica serovar Gallinarum was detected by the MSRV method with low accuracy, sensitivity, and negative predictive value. The detection level of motile strains was 2 ×10(0) to 22 × 10(2) cfu per 25 g for these methods, whereas it was 6.9 × 10(2) cfu per 25 g in culture methods for Salmonella Gallinarum. Extending the incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. On the other hand, accuracy and sensitivity values were higher in MSRV-PCR and tetrathionate-PCR methods than in the buffered peptone water-PCR method. Specificity and positive predictive values were equal to one in most of the cases. In terms of detection limits, motile Salmonella strains were recovered from 5 × 10(0) cfu per 25 g in MSRV-PCR and tetrathionate-PCR methods, whereas the detection limit was better for nonmotile Salmonella in MSRV-PCR methods than in the tetrathionate-PCR method. Kappa coefficients showed that there was a very good agreement between tetrathionate and MSRV methods for motile Salmonella strains, whereas these methods did not show any concordance for nonmotile Salmonella strains. When buffered peptone water-PCR was compared with both tetrathionate-PCR and MSRV-PCR, agreement was poor for motile Salmonella strains and slight to fair for nonmotile Salmonella strains. The difference in isolation rate obtained with the methods used for motile and nonmotile Salmonella strains must be taken into account when a poultry fecal sample is considered negative for the presence of Salmonella.

A comparative study of culture methods and polymerase chain reaction assay for Salmonella detection in poultry feed.

The present work compared 2 culture methods and PCR assay for the detection of motile and non-motile Salmonella strains using artificially contaminated poultry feed. The specificity was 1 in all methods. The accuracy and sensitivity were between 0.5 and 1 for motile Salmonella strains, whereas these parameters were between 0 and 0.6 for non-motile Salmonella strains. The positive predictive value was 1 for tetrathionate (TT), PCR, and modified semisolid Rappaport-Vassiliadis (MSRV) methods in most of the strains studied. The negative predictive value of each method was very low for non-motile Salmonella strains. The detection level of motile strains was 8 to 20 cfu/25 g for all methods, whereas it was ≥10(4) cfu/25 g in culture methods for non-motile Salmonella strains. In general, the PCR method detected lower non-motile Salmonella contamination levels in feed than did culture methods. Extending incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. All selective plating media did not show any statistical differences in the parameters of performance studied. Kappa coefficients showed that there was good agreement between TT and MSRV methods, and MSRV and PCR methods for motile Salmonella strains in poultry feed samples. The agreement was fair between TT and PCR methods for these strains. For non-motile Salmonella strains, there was poor (TT and MSRV methods), slight (PCR and TT methods), and fair (MSRV and PCR methods) agreement. The TT, MSRV, and PCR methods are similar in terms of accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for different motile Salmonella strains in poultry feed. For non-motile Salmonella strains, the use of the PCR method improves the same parameters, described before, in this matrix. The difference in detection levels obtained with the methods used for motile and nonmotile Salmonella strains and the difficulty to detect these last strains represent a potential problem, when a poultry feed sample is considered negative for the presence of Salmonella.

Seroprevalence of Salmonella and Mycoplasma infection in backyard chickens in the state of Entre Rios in Argentina.

The present work was conducted to study the seroprevalence of Salmonella, Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS) infection in backyard chickens located in Entre Ríos, Argentina, over 3 periods of time. A total of 2,441 sera samples were collected from backyard chickens belonging to 256 family farms in 16 counties in the state of Entre Ríos from January to May 2003 (first period), December 2004 to April 2005 (second period), and October 2006 to May 2007 (third period). The prevalence of family farms testing seropositive for Salmonella averaged 23.9, 15.9, and 28.6% during the first, second, and third period, respectively. The highest prevalence of Salmonella-seropositive farms recorded (66.7%) was on farms from Concordia county, and the lowest prevalence (0%) was on farms from La Paz county. In contrast, the prevalence of family farms seropositive for MG averaged 32.8, 55.1, and 76.2% during the first, second, and third periods, respectively. The highest prevalence of MG-seropositive farms (100%) was found in the counties of Victoria and Tala, and the lowest prevalence (8.7%) was found on farms on Colón county. The prevalence of family farms seropositive for MS averaged 68.6 and 100% during the first and second periods, respectively. The highest prevalence of MS-seropositive farms (100%) was on farms in 85% of the counties tested, and the lowest prevalence (21.7%) was on farms from Colón county. Salmonella, MG, and MS infection are present at high levels in backyard chicken farms, and this presents a high risk to commercial poultry production in Entre Ríos, the state with the highest chicken population and density in Argentina.

Mycoflora in commercial pet foods.

This article reports on the identification of mycoflora of 21 dry pet foods (12 belonging to dogs and 9 to cats) that corresponded to 8 commercial brands made in Argentina and imported. The isolation frequency and relative density of the prevalent fungal genera are compared too. Ten genera and fungi classified as Mycelia sterilia were identified. The predominant genera were Aspergillus (62%), Rhizopus (48%), and Mucor (38%). The most prevalent among Aspergillus was Aspergillus flavus followed by Aspergillus niger and Aspergillus terreus. The predominant Mucor was Mucor racemosus followed by Mucor plumbeus and Mucor globosus. The moisture content of these foods ranged from 5.6 to 10.0% and from 7.2 to 9.9% for dog and cat foods, respectively. A greater moisture content in food for the senior category (9.5 +/- 0.2) was observed only in comparison to adult and kitten/puppy. If the moisture content can be maintained at these levels, mold growth would be prevented or at least it would remain at an insignificant level. Some genera and species isolated and identified from the foods analyzed are potentially producing toxins, which are known as mycotoxins. This involves a risk for animal health.

The operating room as a theater--a relevant metaphor.

Any metaphor can be stretched to absurdity. Nonetheless, the operating room as a theater can be a relevant and useful analogy. In the OR theater, the play is always a drama, sometimes a tragedy, occasionally even a comedy of errors, but never, never is it a Broadway musical.

Competence, criteria, and credentialing.

Nurse executives, administrators, and managers are constantly being challenged by the changes in healthcare. Although it sometimes seems there is really nothing new, proactive visionary nurse administrators can rediscover, redesign, and redirect their own and others' activities to achieve organizational effectiveness. Such approaches require periodic examination of all strategies and practices--past, present, and future--for their relevance, practicality, and success. The editors of "Executive Development" reflect on topics important to organizational life.

Nurse executive turnover.

Nurse executives may change their employment status frequently and sometimes unexpectedly. This study describes the employment patterns among nurse executives participating in the Johnson and Johnson Wharton Fellows Program.