Investigating academic performance and perceptions of human physiology and exercise physiology courses among undergraduate students of physical education at a Brazilian public university.

PURPOSE: To compare the academic performance of undergraduate students in physical education who studied exercise physiology before and after studying human physiology and investigate students' perceptions of human physiology and exercise physiology courses. METHODS: This study included 311 undergraduate students pursuing a bachelor's degree in physical education. Participants were divided into two groups: those who had previously attended and completed the human physiology course (group 1, n = 212, 68.2%) and those who had not previously attended or had attended but failed the human physiology course (group 2, n = 99, 31.8%). The prevalence ratio (PR) and 95% confidence interval (95% CI) were calculated using a Poisson regression model with a robust variance estimator. The second aim comprised 67 students with bachelor's degrees in physical education who completed an electronic questionnaire about their perceptions of human physiology and exercise physiology curriculum. RESULTS: Compared with those who attended human physiology and passed, those who had not previously attended or had attended but failed the human physiology course have a higher PR of 2.37 (95% CI, 1.68-3.34) for failing exercise physiology. Regarding the students' perceptions of human physiology and exercise physiology courses, most students reported that they were challenging (58.2% and 64.2%, respectively), but they also recognized the importance of these courses for professional practice (59.7% and 85.1%, respectively). CONCLUSION: Human physiology should be considered a prerequisite for an undergraduate course leading to a bachelor's degree in physical education. Furthermore, students considered human physiology and exercise physiology courses important yet challenging. Therefore, continuous student assessment is vital for improving the teaching-learning process.

Technology and Sleep Quality: Friend or Foe? Let the Exergames Come into Play!

Low sleep quality is associated with many health problems. Although physical exercise is a nonpharmacological tool that positively impacts sleep quality, there are many barriers (lack of energy, lack of motivation, lack of skills, lack of resources, and fear of injury) for people to adopt an active lifestyle. Exergames are an alternative way of physical exercise that are funnier and more attractive than traditional forms of physical exercise and, therefore, has the potential to increase adherence to a physical exercise program. Given that previous studies showed that exergames presents similar physiological and psychological outcomes to traditional forms of exercise, we aimed to discuss in this narrative review potentials applications, limitations and perspectives of using exergames to improve sleep quality.

Presence of exercise physiology or similar coursework in the curricula of Brazilian health science undergraduate programs.

Bolstered by evidence of the health benefits of exercise, health professionals advise their patients about it. Thus these professionals should have a basic knowledge of exercise physiology. In Brazil, a graduate degree is not mandatory, so for many health providers, the only opportunity to receive information on exercise physiology content is during their undergraduate study. Therefore, it is imperative that health science undergraduate programs include content on exercise physiology. The aim of the study was to verify the presence of exercise physiology (or similar coursework) in the curricula of seven health science undergraduate programs (biomedicine, physical education, nursing, physiotherapy, medicine, nutrition, and psychology). The study was divided into three phases: 1) a survey of the total number of undergraduate programs (n = 4,940) through an electronic system of the Brazilian Ministry of Education (e-MEC); 2) a random selection of 10% of the total undergraduate programs (n = 494) for further analysis of the curriculum; and 3) analysis of the curricula of the selected undergraduate programs. Of 494 undergraduate programs, we did not find curricula for 77 of them. Therefore, the final sample consisted of 417 undergraduate programs. In total, 65.9% of the undergraduate programs did not offer coursework in exercise physiology. The chi-square test revealed a significant association between undergraduate curricula in health science and the presence or absence of exercise physiology coursework [X2(6, n = 417) = 293.0, P < 0.0001]. We did not find exercise physiology coursework in most of the analyzed undergraduate programs. Alternatives to solve the lack of exercise physiology coursework would be the inclusion of content related to exercise physiology in professional/graduate education or in continuing education programs.

Resistance Training, Fatigue, Quality of Life, Anxiety in Breast Cancer Survivors.

ABSTRACT: Moraes, RF, Ferreira-Júnior, JB, Marques, VA, Vieira, A, Lira, CAB, Campos, MH, Freitas-Junior, R, Rahal, RMS, Gentil, P, and Vieira, CA. Resistance training, fatigue, quality of life, anxiety in breast cancer survivors. J Strength Cond Res 35(5): 1350-1356, 2021-Resistance training (RT) has shown to be effective in improving fatigue, quality of life (QOL), and anxiety levels among breast cancer survivors (BCS), but there is no consensus as to how this practice should be prescribed for optimal performance. This study analyses the effects of once weekly RT on fatigue, QOL, and anxiety levels among BCS. Randomized controlled trial. Twenty-five BCS (aged 54.6 ± 5.5 years) were randomized into RT or control groups. The RT group performed 8 weeks of RT (once per week). Fatigue was assessed using the Piper Fatigue scale, QOL was assessed using the SF-36, and anxiety was assessed using the STAI State-Trait Anxiety Inventory. Resistance training significantly improved the following subscales of SF-36: aspects of physical functioning (+27%, p = 0.027); physical role functioning (+54%, p = 0.008); emotional role functioning (+42%, p = 0.027); and mental health (+16%, p = 0.032). Furthermore, RT improved fatigue levels (-55%, p = 0.001 for general fatigue) and anxiety (anxiety state, -19%, p = 0.012; anxiety trait, -23%, p = 0.001). Resistance training seemed to be a positive nonpharmacological tool for the reduction of fatigue, anxiety, and for improvement of several aspects of QOL in BCS.

Back Squat vs. Hip Thrust Resistance-training Programs in Well-trained Women.

The study compared the effects of back squat (BS) and hip thrust (HT) exercises on muscle strength and hypertrophy in well-trained women. Twenty-two participants were divided in two groups: BS group (n=12, 26.4±1.32 years, 171.8±3.79 cm, and 69.5±4.9 kg) performed the BS exercise and HT group (n=10, 27.5±1.42 years, 170.8±4.4 cm, 67.5±4.7 kg) performed the HT exercise. Training was performed for 12 weeks. Before and after the training period, participants were assessed for quadriceps femoris and gluteus maximus muscle thickness (MT) and 1 repetition maximum (1RM) test on the BS and HT. Both groups significantly increased hip extensors MT and HT 1RM; however, the improvements in BS group were higher than in HT group on quadriceps femoris (12.2% for BS and 2% for HT, P<0.001) and gluteus maximus MT (9.4% for BS and 3.7% for HT, P=0.001) and BS 1 RM (35.9% for BS and 4.3% for HT, P<0.001). BS was more efficient than HT, since it resulted in greater muscle hypertrophy of the quadriceps femoris and gluteus maximus, increases in BS 1RM and similar increases in HT.

Analysis of type 2 diabetes mellitus and arterial hypertension content in exercise physiology textbooks.

The textbook is a pedagogical tool that provides students and professionals with scientific information. As exercise is an important strategy for the prevention and treatment of noncommunicable diseases, such as type 2 diabetes mellitus (T2DM) and arterial hypertension, the presence of correct and up-to-date scientific information in exercise physiology textbooks is important. Our aim was to analyze T2DM and arterial hypertension content in exercise physiology textbooks and compare this content with the American College of Sports Medicine (ACSM) position stands. Comparative descriptions were made between information regarding T2DM and arterial hypertension found in textbooks (n = 10) and similar information contained in the official ACSM position stands. The quality of the content was compared with current scientific information present in the ACSM position stands. In regards to T2DM, eight textbooks provided information regarding the purpose and benefits of exercise, two provided information regarding exercise prescription, seven provided information regarding the type of exercise, six provided information regarding general care and recommendations, and five provided information regarding the mechanisms involved. In regards to arterial hypertension, all textbooks provided information regarding the purpose and benefit of exercise, six provided information regarding exercise prescription, nine provided information regarding the type of exercise, two provided information regarding general care and recommendations, and seven provided information regarding the mechanisms involved. All textbooks analyzed contained information related to physical exercise for patients with T2DM and arterial hypertension. However, the textbooks differed in terms of the quality of the contents, especially in regard to exercise prescription.

Plant Microbial Fuel Cells⁻Based Energy Harvester System for Self-powered IoT Applications.

The emergence of modern technologies, such as Wireless Sensor Networks (WSNs), the Internet-of-Things (IoT), and Machine-to-Machine (M2M) communications, involves the use of batteries, which pose a serious environmental risk, with billions of batteries disposed of every year. However, the combination of sensors and wireless communication devices is extremely power-hungry. Energy Harvesting (EH) is fundamental in enabling the use of low-power electronic devices that derive their energy from external sources, such as Microbial Fuel Cells (MFC), solar power, thermal and kinetic energy, among others. Plant Microbial Fuel Cell (PMFC) is a prominent clean energy source and a step towards the development of self-powered systems in indoor and outdoor environments. One of the main challenges with PMFCs is the dynamic power supply, dynamic charging rates and low-energy supply. In this paper, a PMFC-based energy harvester system is proposed for the implementation of autonomous self-powered sensor nodes with IoT and cloud-based service communication protocols. The PMFC design is specifically adapted with the proposed EH circuit for the implementation of IoT-WSN based applications. The PMFC-EH system has a maximum power point at 0.71 V, a current density of 5 mA cm - 2 , and a power density of 3.5 mW cm - 2 with a single plant. Considering a sensor node with a current consumption of 0.35 mA, the PMFC-EH green energy system allows a power autonomy for real-time data processing of IoT-based low-power WSN systems.

Efficacy of a Polyglycol Dimethacrylate-Based Adhesive in Sealing the Implant-Abutment Interface.

PURPOSE: The purpose of this study was to assess the effectiveness of a polyglycol dimethacrylate-based adhesive in preventing bacterial leakage through implant-abutment interfaces (IAIs). MATERIALS AND METHODS: After implant installation, the adhesive was applied in the experimental group (n = 10). None was applied in the control group (n = 10). Samples were collected from the inner walls of implants on days 0 and 90. The real-time polymerase chain reaction was used to detect bacterial DNA. RESULTS: All samples from the control group, versus 30% from the experimental group, harbored bacterial DNA on day 90. CONCLUSIONS: This polyglycol dimethacrylate-based adhesive may be used to seal the IAI. Further studies are warranted to verify its effectiveness over longer time periods.

Qualitative, quantitative and genotypic evaluation of Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum isolated from individuals with different periodontal clinical conditions.

Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum are strongly associated with periodontitis, and their evaluations are relevant to understand their role in the etiology and progression of periodontal diseases. In this study, the qualitative and quantitative detection of A. actinomycetemcomitans and F. nucleatum, as well as their genetic diversity, were evaluated in individuals with gingivitis, chronic periodontitis and periodontally healthy. In addition, the biotyping, serotyping, and prevalence of the ltx and cdt genes in A. actinomycetemcomitans were also determined. Subgingival biofilms obtained from gingivitis (70), periodontitis (75) and healthy (95) individuals were analyzed by cultures and PCR. Bacterial typing and presence of ltx and cdt genes in A. actinomycetemcomitans were also verified. DNA from A. actinomycetemcomitans and F. nucleatum was detected respectively, in 65.7% and 57.1% of gingivitis, 80% and 68% of periodontitis, and 57.8% and 37.8% of healthy. A. actinomycetemcomitans from gingivitis were biotypes I, II, IV, V, and X, and serotypes a, c, and e. In periodontitis, biotypes II, VI, and X, and serotypes a, b, and c were found. In healthy subjects, biotypes II and X, and serotypes b and c were found. The LTX and ltxA were observed in strains from gingivitis and periodontitis pockets. Subsequently, our data also showed no direct relationship between ltxA gene expression and leukotoxin gene 530-bp presence. On the other hand, cdt gene predominated during the inflammatory disease process. Our results strongly support a role of A. actinomycetemcomitans and F. nucleatum in advanced stage of periodontal disease.

Genetic variation among Clostridium perfringens isolated from food and faecal specimens in Lagos.

BACKGROUND: Clostridium perfringens is an anaerobic Gram-positive bacterium which is commonly present in the gastrointestinal tract of man and animals and causes enteritic diseases in animals and food poisoning in humans. Previous studies have looked at the epidemiological relationship between C. perfringens isolates from outbreak source. In this study, the genetic diversity of C. perfringens strains from non-outbreak food and faecal specimens was investigated for epidemiological purposes. METHODS: We analyzed thirty-eight (38) Clostridium perfringens strains isolated from food and faecal specimens in Lagos State. Bacterial identification was done using colonial morphology, Gram stain reaction, conventional biochemical tests and PCR. Genetic analysis was performed using arbitrary primed polymerase chain reaction (AP-PCR) technique with oligonucleotide primer of random sequences (OPA-3) to determine the genetic diversity of C. perfringens. The distance between the different bands produced were analyzed using numerical taxonomy and multivariate system software (NTSYS). RESULTS: Seventeen (44.7%) C. perfringens strains showed at least one polymorphic DNA patterns when genotyped. However, this method identified polymorphisms among the C. perfringens species from which four genetic groups (1, 2, 3 and 4) were established. CONCLUSIONS: Our findings suggest that there may be faecal contamination of food products and similar clones of Clostridium perfringens may be incriminated.

The aggravation of arthritis by periodontitis is dependent of IL-17 receptor A activation.

AIM: To evaluate whether Porphyromonas gingivalis-induced periodontitis aggravates the antigen-induced arthritis (AIA) model, and whether this effect is dependent on the Th17/IL-17 signalling pathway. MATERIALS AND METHODS: Antigen-induced arthritis was triggered by local injection of methylated bovine serum albumin into the knee joint of previously immunized C57BL/6 wild-type (WT) and IL-17 receptor A (IL-17RA)-knockout mice. Periodontal disease in naïve or arthritic mice was induced by oral infection with P. gingivalis. Animals were sacrificed 7, 15 and 30 days after infection. Alveolar bone loss, joint histopathology, articular hyperalgesia and joint cytokine production were assessed, in addition to the proportion of Th17 and Treg cells isolated from the inguinal lymph nodes. RESULTS: No influence of experimentally-induced arthritis was found on the alveolar bone resorption induced by P. gingivalis. However, mice with experimentally-induced arthritis that were exposed to P. gingivalis presented higher joint damage and Th17 frequencies when compared to non-infected mice. The aggravation of arthritis by periodontitis was accompanied by increased TNF and IL-17 production and articular neutrophil infiltration, whereas arthritis aggravation and changes in neutrophil infiltration were absent in IL-17RA-deficient mice. CONCLUSION: The effects of P. gingivalis-induced periodontitis on arthritis are dependent on Th17 expansion and IL-17RA signalling, which lead to increased neutrophil infiltration into the joints.

High intensity interval training does not impair strength gains in response to resistance training in premenopausal women.

PURPOSE: To compare the increases in upper- and lower-body muscle strength in premenopausal women performing resistance training (RT) alone or alongside concurrent high-intensity interval training (CT). METHODS: Sixteen women (26-40 years) were randomly assigned into two groups that performed either RT or CT. Both groups performed the same RT program; however, CT performed additional high-intensity interval training (HIIT) on a bicycle ergometer before RT. The study lasted 8 weeks and the participants were tested for ten repetition maximum (10RM) load in elbow flexion (barbell biceps curl) and knee extension exercises pre- and post-intervention. RT was performed with 10-12 repetitions to self-determined repetition maximum in the first four weeks and then progressed to 8-10. During CT, HIIT was performed before RT with six 1-min bouts at 7-8 of perceived subjective exertion (RPE) and then progressed to eight bouts at 9-10 RPE. RESULTS: Analysis of variance revealed significant increases in upper and lower body strength for both the RT and CT groups. Biceps barbell curl 10RM load increased from 12.9 ± 3.2 kg to 14 ± 1.5 kg in CT (p < 0.05) and from 13 ± 1.8 kg to 15.9 ± 2.5 kg in RT (p < 0.05), with no significant between-groups differences. Knee extension 10RM increase from 31.9 ± 11.6 kg to 37.5 ± 8.5 kg for CT (p < 0.05) and from 30.6 ± 8.6 kg to 41.2 ± 7.4 kg for RT (p < 0.05). CONCLUSION: In conclusion, performing HIIT on a cycle ergometer before resistance training does not seem to impair muscle strength increases in the knee extensors or elbow flexors of pre-menopausal women. This information should be considered when prescribing exercise sessions, since both activities may be combined without negative effects in muscle strength.

The geometric curvature of the spine during the sirshasana, the yoga's headstand.

This study analysed the behaviour of the geometric curvature of the spine during sirshasana. The position of dorsal retroreflective markers was computed via stereophotogrammetric analysis in six males and five females (29.4 ± 8.8 years, 63.0 ± 11.4 kg, 1.66 ± 0.08 m [average ± standard deviation]). The spinal points were projected onto the sagittal and frontal planes of the trunk, a polynomial was fitted to the data and the two-dimensional geometric curvature was quantified. The inferior lumbar lordosis decreased compared to the orthostatic position and gait, which may favour the posterior protrusion of the lumbar spinal nucleus pulposus in people with posterior herniation. The lateral deviation at the middle of the thoracic spine increases during sirshasana, which may reflect increased difficulties for postural control and spinal loads. It could be useful for promoting positive spinal structural and functional chronic adaptations for healthy participants, if the yoga programme is carefully planned and the spinal alignment is carefully monitored during a headstand. However, it may aggravate some spinal diseases, especially scoliosis.

NOD1 in the modulation of host-microbe interactions and inflammatory bone resorption in the periodontal disease model.

Periodontitis is a chronic inflammatory condition characterized by destruction of non-mineralized and mineralized connective tissues. It is initiated and maintained by a dysbiosis of the bacterial biofilm adjacent to teeth with increased prevalence of Gram-negative microorganisms. Nucleotide-binding oligomerization domain containing 1 (NOD1) is a member of the Nod-like receptors (NLRs) family of proteins that participate in the activation of the innate immune system, in response to invading bacteria or to bacterial antigens present in the cytoplasm. The specific activating ligand for NOD1 is a bacterial peptidoglycan derived primarily from Gram-negative bacteria. This study assessed the role of NOD1 in inflammation-mediated tissue destruction in the context of host-microbe interactions. We used mice with whole-genome deletion of the NOD1 gene in a microbe-induced periodontitis model using direct injections of heat-killed Gram-negative or Gram-negative/Gram-positive bacteria on the gingival tissues. In vitro experiments using primary bone-marrow-derived macrophages from wild-type and NOD1 knockout mice provide insight into the role of NOD1 on the macrophage response to Gram-negative and Gram-negative/Gram-positive bacteria. Microcomputed tomography analysis indicated that deletion of NOD1 significantly aggravated bone resorption induced by Gram-negative bacteria, accompanied by an increase in the numbers of osteoclasts. This effect was significantly attenuated by the association with Gram-positive bacteria. In vitro, quantitative PCR arrays indicated that stimulation of macrophages with heat-killed Gram-negative bacteria induced the same biological processes in wild-type and NOD1-deficient cells; however, expression of pro-inflammatory mediators was increased in NOD1-deficient cells. These results suggest a bone-sparing role for NOD1 in this model.

Periodontal pathogens directly promote autoimmune experimental arthritis by inducing a TLR2- and IL-1-driven Th17 response.

Increasing epidemiologic evidence supports a link between periodontitis and rheumatoid arthritis. The actual involvement of periodontitis in the pathogenesis of rheumatoid arthritis and the underlying mechanisms remain, however, poorly understood. We investigated the influence of concomitant periodontitis on clinical and histopathologic characteristics of T cell-mediated experimental arthritis and evaluated modulation of type II collagen (CII)-reactive Th cell phenotype as a potential mechanism. Repeated oral inoculations of periodontal pathogens Porphyromonas gingivalis and Prevotella nigrescens induced periodontitis in mice, as evidenced by alveolar bone resorption. Interestingly, concurrent periodontitis induced by both bacteria significantly aggravated the severity of collagen-induced arthritis. Exacerbation of arthritis was characterized by increased arthritic bone erosion, whereas cartilage damage remained unaffected. Both P. gingivalis and P. nigrescens skewed the CII-specific T cell response in lymph nodes draining arthritic joints toward the Th17 phenotype without affecting Th1. Importantly, the levels of IL-17 induced by periodontal pathogens in CII-specific T cells directly correlated with the intensity of arthritic bone erosion, suggesting relevance in pathology. Furthermore, IL-17 production was significantly correlated with periodontal disease-induced IL-6 in lymph node cell cultures. The effects of the two bacteria diverged in that P. nigrescens, in contrast to P. gingivalis, suppressed the joint-protective type 2 cytokines, including IL-4. Further in vitro studies showed that the Th17 induction strongly depended on TLR2 expression on APCs and was highly promoted by IL-1. Our data provide evidence of the involvement of periodontitis in the pathogenesis of T cell-driven arthritis through induction of Ag-specific Th17 response.

Detection of toxigenic Clostridium perfringens and Clostridium botulinum from food sold in Lagos, Nigeria.

Food-borne diseases contribute to the huge burden of sickness and death globally and in the last decade, have become more frequently reported in Africa. In line with this, food safety is becoming a significant and growing public health problem in Nigeria. Diarrhoea is a common problem in Nigeria and has been reported but there has been little data on the possibility of clostridia as aetiological agents. Clostridium species are ubiquitous in the environment and in the gastrointestinal tract of man and animals and can serve as a marker for faecal contamination. We set out to determine the potential of these foods to transmit Clostridium species. A total of 220 food commodities from six local governments in Lagos State were sampled. Isolates obtained were identified based on cultural, morphological and biochemical characteristics. Toxinotyping was done using multiplex-PCR with primers specific for alpha, beta, epsilon and iota-toxin genes, enterotoxigenic cpe gene and neurotoxigenic BoNt gene. Fifty (22.7%) clostridial species were isolated of which 29 (58%) were identified as C. perfringens. Toxinotyping of the 29 strains showed that 28 (96.6%) were toxin producing C. perfringens type A while one (3.4%) was C. perfringens type D. Two (4%) C. botulinum species were isolated and identified by 16S rRNA sequencing, both harbouring BoNt/A gene. The contamination rates of food with Clostridium species show that food hygiene is a problem and Clostridium species may be a source of food borne disease in Lagos State, Nigeria.

Autonomous Aeromagnetic Surveys Using a Fluxgate Magnetometer.

Recent advances in the research of autonomous vehicles have showed a vast range of applications, such as exploration, surveillance and environmental monitoring. Considering the mining industry, it is possible to use such vehicles in the prospection of minerals of commercial interest beneath the ground. However, tasks such as geophysical surveys are highly dependent on specific sensors, which mostly are not designed to be used in these new range of autonomous vehicles. In this work, we propose a novel magnetic survey pipeline that aims to increase versatility, speed and robustness by using autonomous rotary-wing Unmanned Aerial Vehicles (UAVs). We also discuss the development of a state-of-the-art three-axis fluxgate, where our goal in this work was to refine and adjust the sensor topology and coupled electronics specifically for this type of vehicle and application. The sensor was built with two ring-cores using a specially developed stress-annealed CoFeSiB amorphous ribbon, in order to get sufficient resolution to detect concentrations of small ferrous minerals. Finally, we report on the results of experiments performed with a real UAV in an outdoor environment, showing the efficacy of the methodology in detecting an artificial ferrous anomaly.

Structural and quantitative analysis of a mature anaerobic biofilm on different implant abutment surfaces.

STATEMENT OF PROBLEM: The longevity of dental implants depends on the absence of inflammation in the periimplant tissue. Similar to teeth, pathogenic bacteria can adhere on implant abutment surfaces and cause periimplant disease and consequently implant loss. PURPOSE: The purpose of this in vitro study was to evaluate the influence of physical and chemical properties of 2 common materials used as implant abutments, titanium (Ti) and zirconia (ZrO2), and the use of bovine enamel (BE) as a positive control on biofilm formation. MATERIAL AND METHODS: Biofilm formation was analyzed by growing Porphyromonas gingivalis and Fusobacterium nucleatum as monospecies and mixed species biofilms on the surfaces. The mean roughness (Ra) and surface free energy were evaluated for each material. Mature biofilm, formed after 7 days of incubation, was analyzed quantitatively and qualitatively by colony-forming unit and confocal laser scanning microscopy. RESULTS: The mean roughness in all disks was ≤0.21 µm and did not affect the bacterial adhesion. Titanium showed a greater degree of hydrophilicity compared with BE after 90 minutes of immersion in saliva. The surface free energy did not show differences, with the highest values for BE. Monospecies biofilms formed by P. gingivalis on Ti, and mixed species biofilm on ZrO2 exhibited small numbers of cells on disk surfaces. By confocal imaging, the mixed species biofilm appeared as a thin layer on ZrO2 surfaces. CONCLUSIONS: Material surfaces could have a significant impact on biofilm formation. ZrO2 implant abutment surfaces showed a decrease in anaerobic biofilm compared with Ti and BE.

Sialidase production and genetic diversity in Clostridium perfringens type A isolated from chicken with necrotic enteritis in Brazil.

The sialidase activity and genetic diversity of 22 Clostridium perfringens strains isolated from chickens with necrotic enteritis were determined. Sialidase activity was detected in 86.4 % of the strains. All C. perfringens showed a high value of similarity (>96 %), and they were grouped into seven clusters clearly separated from the other reference bacterial strains. From these clusters four patterns were defined in accordance with their phenotypic (sialidase production and antibiotic resistance profile) and genotypic (presence of nanI and nanJ genes) characteristics. Our results showed heterogeneity among strains, but they were genotypically similar, and it is suggested further studies are needed to better understand the pathogenesis of necrotic enteritis.