Abstract Land snails are a destructive agricultural pest in economic crops, but the populations for that pest are highly influenced by temperature and humidity, therefore climatic changes affected their behavior, distribution and population dynamics, for these reasons researchers should follow up on the changes in their behavior, distribution, and population dynamics. In this study, a survey study was conducted to define land snail species existing at Sharkia Governorate, Egypt, from January 2019 to March 2022 in horticultural, vegetable, and field crops and study the population dynamics for the dominant land snail species. Results showed that there are six species of land snails, these species were, Monacha cartusiana, Succinea putris, Eobania vermiculata, Theba pisana, Helicella vestalis, and Cochlicella acuta. The population dynamics of two prevalent land snail species (M. cartusiana and S. putris), were conducted during two successive growing seasons, the Egyptian clover harbored the highest number of M. cartusiana followed by wheat, while the onion was the lowest one during the study period. In the same trends, the land snail S. putris recorded the highest numbers during the growing season of the Egyptian clover crop. Finally, it is concluded that the land snail M. cartusiana considered the first grade of infestation existed everywhere at Sharkia Governorate, and the population density of the land snail is increase gradually after winter till reach the maximum density in spring.

Resumo Os caracóis terrestres são pragas agrícolas destrutivas em cultivos econômicos, todavia, as populações dessa praga são altamente influenciadas pela temperatura e umidade, portanto as mudanças climáticas afetam seu comportamento, distribuição e dinâmica populacional, e, por essas razões, os pesquisadores devem acompanhar as mudanças em seu comportamento, distribuição e dinâmica populacional. O presente trabalho foi realizado para definir as espécies de caracóis terrestres existentes na província de Sharkia, no Egito, de janeiro de 2019 a março de 2022 em culturas hortícolas, vegetais e de campo, e estudar a dinâmica populacional das espécies dominantes de caracóis terrestres. Os resultados mostraram que existem seis espécies de caracóis terrestres, essas espécies foram Monacha cartusiana, Succinea putris, Eobania vermiculata, Theba pisana, Helicella vestalis e Cochlicella acuta. A dinâmica populacional de duas espécies predominantes de caracóis terrestres (M. cartusiana e S. putris), foi conduzida durante duas safras sucessivas, o trevo egípcio abrigou o maior número de M. cartusiana seguido pelo trigo, enquanto a cebola foi o menor durante o período de estudo. Seguindo as mesmas tendências, o caracol terrestre S. putris registrou os números mais altos durante a estação de crescimento da cultura do trevo egípcio. Finalmente, conclui-se que o caracol terrestre M. cartusiana, considerado o primeiro grau de infestação, está presente em toda a província de Sharkia, e a densidade populacional do caracol terrestre aumenta gradualmente após o inverno até atingir a densidade máxima na primavera.

We investigated the effects of fucoxanthin isolated from the edible macroalga Dilophys fasciola on pathogenic microbes and probiotics in vitro and the antioxidant activity of fucoxanthin. The yield concentration of the obtained crude was 50.5% fucoxanthin. We found strong inhibition against Gram-positive Staphylococcus aureus and Listeria monocytogenes, and lower inhibition against Gram-negative bacteria and fungi. The probiotic strains progressed between 1.2 and 1.67 log cycles at a concentration of 30 µg/mL. The antioxidant activity ranged between 54.76% and 88.36% at a concentration of 40 µg/mL. The 50% lethal dose of algal fucoxanthin was shown to be more than 2511.88 mg/kg. The production of stirred yoghurt incorporated with 20 mg and 30 mg of fucoxanthin per kilogram of milk was evaluated through chemical, microbiological, and sensory analyses during storage for 21 days and compared with control samples. The maximum growth for probiotics (Bifidobacterium bifidum and Lacticaseibacillus casei) was found on day 14, but more viability counts were detected in the treatment with 30 mg/kg. All treatments were free from mould and yeast counts up to 7 days, and the small numbers of mould, yeast, and psychrotrophic counts appeared first in control samples. Also, the highest dry matter content was observed for treatments with 30 mg/kg. Moreover, the protein, fat, and ash content of all treatments increased with a progressive cold storage period. Greater reductions in the pH were found in treatments than in the control, and were consistent with the development of acidity. During storage, the amount of crude fucoxanthin had no significant impact on the flavour, colour, or appearance scores. SIGNIFICANCE: • Fucoxanthin is a type of carotenoid that offers many benefits to human health. • The fucoxanthin of edible Dilophys fasciola had a strong antimicrobial effect against Gram-positive bacteria, Gram-negative bacteria, and fungi. • Stirred yoghurt fortified with crude fucoxanthin had good overall acceptability and the percentage of crude fucoxanthin had no noticeable effects on the flavour, colour, or appearance. Fucoxanthin, therefore, has potential benefit as a food additive.

ABSTRACT Marine bacteria associated with Mediterranean Sea snails have not been explored intensively. The aim of the study was to explore marine pigmented bacteria associated with the sea snailThaissp. commonly found in Alexandria seashores where a red-pigmented bacterium was isolated and identified asVibriosp. based on phenotypic traits and 16S rRNA gene sequence analysis. Based on ultraviolet-visible (UV-vis) spectral and liquid chromatography-mass spectrometry (LC-MS) analysis, the red pigment was identified as a prodigiosin-like pigment. To our knowledge, this is the first report on the isolation of aVibriostrain from a gastropod able to synthesize prodigiosin. Maximum production (7 mg/L) was achieved after two days in MZM cultures containing 0.5% mannitol and 2.5% soybean meal, pH 7 and statically incubated at 30 °C, using Plackett-Burman factorial design. RT-qPCR revealed thatpks-1 andnrpsresponsible for the biosynthesis of prodigiosin and other bioactive compounds were up-regulated by the addition of sublethal concentrations of imipenem, DMSO, and the heavy metals copper oxide and chromium VI oxide. Through this work it can be concluded that marine invertebrates should be further explored for bacteria producing bioactive compounds whose synthesis can be enhanced or blocked depending on the carbon and nitrogen sources adopted in the fermentation medium. Moreover, the mRNA expression of the genes responsible for prodigiosin-like pigment production can be up-regulated through adopting sub-lethal concentrations of stress inducing compounds as well as co-cultivation.

RESUMEN Las bacterias marinas asociadas con los caracoles del mar Mediterráneo no se han explorado intensamente. El objetivo del estudio fue explorar las bacterias pigmentadas marinas asociadas con el caracol de mar Thais sp. se encuentra comúnmente en las costas de Alejandría, donde se aisló una bacteria de pigmento rojo que se identificó como Vibrio sp. basado en rasgos fenotípicos y análisis de la secuencia del gen 16S rRNA. Sobre la base del análisis espectral ultravioleta-visible (UV-vis) y cromatografía líquida-espectrometría de masas (LC-MS), el pigmento rojo se identificó como un pigmento similar a la prodigiosina. Hasta donde sabemos, este es el primer informe sobre el aislamiento de una cepa de Vibrio de un gasterópodo capaz de sintetizar prodigiosina. La producción máxima (7 mg/L) se logró después de dos días en cultivos MZM que contenían 0,5 % de manitol y 2,5 % de harina de soya, pH 7 e incubados estáticamente a 30 °C, usando un diseño factorial de Plackett-Burman. RT-qPCR reveló que pks-1 y nrps responsables de la biosíntesis de prodigiosina y otros compuestos bioactivos estaban regulados al alza por la adición de concentraciones subletales de imipenem, DMSO y los metales pesados óxido de cobre y óxido de cromo VI. A través de este trabajo, se puede concluir que los invertebrados marinos deben explorarse más a fondo en busca de bacterias que produzcan compuestos bioactivos cuya síntesis se puede mejorar o bloquear según las fuentes de carbono y nitrógeno adoptadas en el medio de fermentación. Además, la expresión del ARNm de los genes responsables de la producción de pigmentos similares a la prodigiosina se puede regular mediante la adopción de concentraciones subletales de compuestos inductores de estrés, así como mediante el cultivo conjunto.

ABSTRACT: Coccidian infection may promote the proliferation of gut bacteria of the family Enterobacteriaceae. Bacterial infections by members of this family in rabbits can induce a negative impact on their health and lead to high mortality, especially in young individuals. This study aimed to investigate the effect of prebiotic treatment on Escherichia coli and Salmonella species during natural intestinal coccidiosis in rabbits. Forty-five rabbits were selected from a rabbit farm in Beni-Suef, Egypt. Out of the 45 rabbits, 15 were coccidia-free and used as the negative control group (NC group) and 30 were naturally infected with coccidia. The infected rabbits were randomly divided into two equal groups, the positive control group (PC) and the prebiotic treated group (PT) which was orally treated with prebiotic for 8 successive days. Faecal oocyst count was assessed daily during the course of treatment. At 8 days post-treatment, 5 rabbits from each group were euthanised for the microbiological examination of the intestinal tract. On day 8 post treatment, the PT group showed a significant (P<0.05) reduction in the oocyst count (5.33 x103 ± 0.89) with a significant (P<0.05) decline in the prevalence of E. coli and Salmonella (66.7 % and 26.4%, respectively). The PC group showed highly a significant oocyst count (21.67x103 ± 0.82 OPG), with a significant increase in the prevalence of E. coli and Salmonella (86.7 % and 46.7 %, respectively). The NC group remained coccidian free and exhibited only E. coli with no Salmonella infection. The in vitro susceptibility test showed that E. coli isolates were highly resistant to most of the tested antimicrobials while Salmonella isolates showed variable resistance profiles. In conclusion, the prebiotic treatment significantly reduced the prevalence of E. coli and Salmonella infections coexisted with intestinal coccidiosis naturally infected rabbits.

Abstract: In our consideration, we studied vibrations analysis and dynamic responses of a Hybrid Rayleigh-Van der Pol- Duffing oscillator. This system presented by one -degree- of - freedom containing the fifth order of nonlinear terms and an external force. The proportional derivative controller (PD) was used to control the vibration of the main system. The average method used to obtain the approximate solution of the vibrating system. The stability of the system is investigated at the primary resonance case (Ω = ω). Numerically, we used Runge-Kutta of the fourth order to scrutinize the time histories of the system before and after using PD. For response curves, we investigated the performance of some chosen parameters of studied system. Finally, there is a good agreement between the approximate solution which obtained from the average method and the numerical one.

Abstract This work is meant to investigate and control the nonlinear dynamical behaviours of a nonlinear asymmetric rotating shaft system. The studied system is modeled as a nonlinear dynamical system having both quadratic and cubic nonlinearities and excited at the primary resonance. A linear proportional-derivative controller is introduced to eliminate the nonlinear behaviours and to suppress the lateral vibrations of the rotating shaft. The influences of different control parameters on the oscillatory behaviours of the considered system are explored. The main obtained analytical results showed that the uncontrolled shaft may respond with forward and backward whirling motion. However, the proposed controller illustrated its feasibility in eliminating the nonlinear behaviours of the studied system and forcing it to behave like the linear systems. Moreover, the obtained results confirmed that the proportional control gain plays a dominant role in destabilizing the studied rotor system. Finally, the safe operation of the studied system with avoiding the rub-impact force occurrence is discussed.

RESUMO Introdução: A hepcidina está associada à patogênese da anemia por insuficiência renal crônica, considerada um estado inflamatório crônico e também infecção por HCV. A IL-6 estimula a liberação de hepcidina a partir do fígado, suprime a captação intestinal de ferro e libera ferro das reservas internas. Método: Para detectar a associação entre o polimorfismo do gene IL-6 e os marcadores de anemia, 80 pacientes em hemodiálise (HD) [40 pacientes em HD, negativos para HCV; e 40 em HD, positivos para HCV] foram avaliados por exames químicos de rotina e hemograma completo, além da avaliação da hepcidina sérica, parâmetros do ferro [ferro sérico e ferritina sérica] e marcadores de hepatite C. O polimorfismo da IL-6 -174G/C foi determinado por MS-PCR, enquanto os polimorfismos de IL-6 -597G/A e -572 G/C foram detectados por PCR-SSP. Resultados: A hepcidina não esteve significativamente elevada em pacientes com HCV em comparação com pacientes em hemodiálise negativos para HCV. Uma diferença estatisticamente significativa foi detectada entre os pacientes em HD HCV negativos comparados aos positivos nas frequências de IL-6 -174 G/C e -597 G/A (P≤ 0,01 e P≤ 0,001, respectivamente). Por outro lado, foi relatada uma diferença não significativa entre pacientes em HD HCV negativos e positivos nas frequências de IL-6 -572 G/C. Conclusões: Nosso estudo indicou que os polimorfismos de IL-6 -174 G/C e -597 G/A podem desempenhar um papel na suscetibilidade ao HCV em pacientes em HD. Ainda necessitamos de estudos prospectivos adicionais em uma população maior para confirmar nossos achados.

ABSTRACT Backgrounds: Hepcidin is related to the pathogenesis of chronic renal failure anemia, which is considered a chronic inflammatory state as well as HCV infection. IL-6 stimulates the release of hepcidin from the liver, suppresses intestinal iron uptake, and releases iron from internal stores. Method: To detect the association between IL-6 gene polymorphism and anemia markers, 80 hemodialysis (HD) patients [40 negative HCV HD patients and 40 positive HCV HD patients] were studied by routine chemistry and complete blood count, in addition to the assessment of serum hepcidin, iron parameters [serum iron and serum ferritin], and hepatitis C markers. IL-6 polymorphism -174G/C was determined by MS-PCR, while IL-6 polymorphisms -597G/A and -572 G/C were detected by PCR-SSP. Results: Hepcidin was non-significantly elevated in HCV-positive compared with HCV-negative hemodialysis patients. A statistically significant difference was detected between the negative and positive HCV HD patients in frequencies of IL-6 -174 G/C and -597 G/A (P≤ 0.01 and P≤ 0.001, respectively). On the other hand, a non-significant difference was reported between negative and positive HCV HD patients in the frequencies of IL-6 -572 G/C. Conclusions: Our study indicated that IL-6 -174 G/C and -597 G/A polymorphisms may play a role in HCV susceptibility in HD patients. Additional prospective studies on a larger population are needed to confirm our findings.

Abstract This study investigated the impact of supplementing normal and high-fat diets with graded levels of lycopene on the growth performance, cholesterol level of the muscle, and antioxidant markers in Japanese quail. A total of 192, 14 day-old unsexed Japanese quail were part of a 2 x 4 factorial arrangement consisting of a control group; birds that were fed a normal fat diet (NFD), another control group; birds that were fed a high-fat diet (HFD) with four levels of lycopene for NFD and HFD (0, 100, 200 and 300mg lycopene/kg diet). Lycopene level of 300mg/kg gave the greatest body weight, body weight gain, and relative growth rate when added to the NFD, but this level showed non-significant improvement in growth performance when supplemented to an HFD. Superoxide dismutase in the muscle and liver was noted to be high in NFD+ 300mgL, HFD+ 200mgL, and HFD+ 300mgL groups, while malondialdehyde level in the muscle and liver and cholesterol level in the muscle was found to be low in the same groups. Lycopene slightly improved growth performance, but significantly improved the antioxidant status and lowered cholesterol concentration in the muscle. A diet supplemented with 300 mg lycopene/kg could be recommended for Japanese quail.

Abstract Cadmium, present in the environment, accumulates in different organs of animals and humans, and has deleterious effects on the kidney. In this study, we investigated the protective effects of the methanolic extract of Pleurotus ostreatus in comparison with silymarin on renal function in cadmium-intoxicated rats for five days. Rats intraperitoneally injected with cadmium chloride (1 mg/kg). These rats were treated with either P. ostreatus extract (200 mg/kg) or silymarin to investigate the protective effects of the extract. Cadmium treatment induced significant histopathological impairments and increased cadmium levels, DNA fragmentation, and renal oxidative stress. However, treatment with P. ostreatus extract or silymarin improved the pathology, reduced the level of cadmium in renal tissue, and restored DNA fragmentation. In addition, a significant reduction in lipid peroxidation and reactive oxygen species levels, and a significant increase in the levels of glutathione and catalase activity were observed. Thus, protective effects of P. ostreatus extract to its components. Chromatographic analysis of the P. ostreatus confirmed the presence of five phenolics (gallic acid, chlorogenic acid, catechin, propyl gallate, and cinnamic acid) that exhibit strong antioxidant properties as free radical scavengers. Therefore, our findings demonstrate that treatment with P. ostreatus extract protects against cadmium-induced nephrotoxicity in female rats.

ABSTRACT Chemical profile analyses of artichoke (Cynara scolymus L., Asteraceae) edible parts (fleshy receptacle, inner bracts) as well as roots are compared with the commercially usable leaf extract using HPLC-DAD-ESI-MS via chlorogenicacid as a marker. Overall polyphenolic constituents demonstrated by means of LC/MS profiling. The nutritional values and inulin contents of different assessed parts were investigated. The present study was designed to determine the effect of artichoke: leaves, bracts, receptacles and roots alcoholic extracts against CCl4-induced acute hepatotoxicity and hyperlipidemia in rats by means of histopathological and biochemical parameters. Serum liver enzymes levels of aspartate amino transferase, alanine amino transferase, alkaline phosphatase and lipid peroxidase content (malondialdehyde MDA) were estimated. Blood glutathione, total cholesterol, triacylglycerides and high density lipid level were estimated in plasma. The ethanol extract of roots, leaves, bracts and receptacles were standardized to (0.82 ± 0.02, 1.6 ± 0.06, 2.02 ± 0.16 and 2.4 ± 0.27 mg chlorogenic acid/100 mg extract), respectively. The receptacle showed the highest content of polyphenols and exhibits the highest antioxidant activity. HPLC analysis of inulin in the receptacles of globe artichoke revealed high content of inulin (41.47 mg/g) dry extract. All artichoke parts contain comparable vitamins and minerals. Artichokes receptacles extract when taken in dose of (500 mg/kg/day) reduce the lesion caused by CCl4 alone more than groups receiving silymarin. Bracts and leaves extract exert nearly the same effect.

The electrochemical behavior of pramipexole dihydrochloride was studied at carbon paste electrodes in 0.04 M Britton-Robinson buffer of pH 6.08, using cyclic and differential pulse voltammetric techniques. The oxidation of pramipexole dihydrochloride is an irreversible diffusion-controlled process. A differential pulse anodic voltammetric procedure has been developed for determination of the drug over the concentration range of 1.20 - 8.23 μg/mL, with detection and quantification limits of 0.21 and 0.68 μg/mL, respectively. The proposed method was successfully applied for the determination of the drug in its commercial tablets.

RESUMO Antecedentes: A artrite reumatoide é uma doença autoimune amplamente prevalente com sugerida predisposição genética. Objetivos: Detectar o padrão de polimorfismo dos genes metilenotetrahidrofolato redutase (MTHFR C677 T e A1298 C), fator de crescimento transformador β1 (TGF-β1 T869 C) e linfotoxina-α (LT-α A252G) em pacientes com artrite reumatoide e correlacionar esses padrões com a atividade da doença e os níveis séricos de fator de necrose tumoral alfa (TNF-α), fator ativador de linfócitos B (BAFF) e osteopontina. Métodos: Foram genotipados 194 indivíduos – 90 controles e 104 com artrite reumatoide – à procura de polimorfismos dos genes MTHFR C677 T e A1298 C, TGF-β1 T869 C e LT-α A252G com uma metodologia baseada na PCR-RFLP. Mensuraram-se também os níveis séricos de TNF-α, osteopontina e BAFF com kits de Elisa. Resultados: O genótipo CT e o alelo T do MTHFR C677 T e o genótipo GG e alelo G do LT-α A252G estão associados ao risco de AR e a níveis mais elevados da citocina pró-inflamatória TNF-α em pacientes com artrite reumatoide. Conclusão Os achados do presente estudo sugerem que há associação entre os polimorfismos dos genes MTHFR C677 T e LT-α A252G e um risco aumentado de AR nessa amostra da população egípcia.

ABSTRACT Background: Rheumatoid arthritis is a widely prevalent autoimmune disorder with suggested genetic predisposition. Objectives: The aim of this study is to detect the pattern of genetic polymorphism of methylene tetrahydrofolate reductase (MTHFR C677 T and A1298 C), transforming growth factor-β1 (TGF-β1 T869 C) and lymphotoxin-α (LT-α A252G) in patients having rheumatoid arthritis and correlate these patterns to disease activity and serum levels of tumor necrosis factor-alpha (TNF-α), B-Cell Activating Factor (BAFF), and osteopontin. Methods: A total of 194 subjects, 90 controls and 104 patients with rheumatoid arthritis were genotyped for MTHFR C677 T and A1298 C, TGF-β1 T869 C and LT-α A252G polymorphisms using a methodology based on PCR-RFLP. Also serum levels of TNF-α, osteopontin and BAFF were measured by ELISA kits. Results: The CT genotype and T allele of MTHFR C677 T and GG genotype and G allele of LT-α A252G are associated with the risk of RA and with higher levels of the pro-inflammatory cytokine, TNF-α in patients with rheumatoid arthritis. Conclusion: Our findings suggest that there is association between MTHFR C677 T and LT-α A252G genes polymorphisms and increased risk of RA in this sample of Egyptian population.

Abstract Genus Aloe, Xanthorrhoeaceae, is well distributed all over Egypt, and many species have been used as medicinal plants; mainly reported to prevent cardiovascular diseases, cancer and diabetes. This study attempts to analyze the secondary metabolites in the methanol extract of the leaves of eight Aloe species; A. vera (L.) Burm. f., A. arborescens Mill., A. eru A. Berger, A. grandidentata Salm-Dyck, A. perfoliata L., A. brevifolia Mill., A. saponaria Haw. and A. ferox Mill. growing in Egypt. For this aim HPLC–DAD–MS/MS in negative ion mode was used. Although belonging to the same genus, the composition of each species presented different particularities. Seventy one compounds were identified in the investigated Aloe species, of which cis-p-coumaric acid derivaties, 3,4-O-(E) caffeoylferuloylquinic acid and caffeoyl quinic acid hexoside were the most common phenolic acids identified. Aloeresin E and isoaloeresin D, 2'-O-feruloylaloesin were the common anthraquinones identified. Lucenin II, vicenin II, and orientin were the common identified flavonoids in the investigated Aloe species. 6'-Malonylnataloin, aloe-emodin-8-O-glucoside, flavone-6,8-di-C-glucosides could be considered as chemotaxonomic markers for the investigated Aloe species. The eight Aloe species had significant anti-inflammatory activity, in addition to the significant acceleration of diabetic wound healing in rats following topical application of the methanol extracts of their leaves. This is the first simultaneous characterization and qualitative determination of multiple phenolic compounds in Aloe species from locally grown cultivars in Egypt using HPLC–DAD–MS/MS, which can be applied to standardize the quality of different Aloe species and the future design of nutraceuticals and cosmetic preparations.

Reinforced concrete wide shallow beams (WSBs) are commonly used in the joist flooring systems. The structural behavior of WSBs strengthened with carbon fiber reinforced polymer (CFRP) reinforcement was studied on isolated beams and as part of full-scale building. The effect of structural damage on the performance of WSBs flexurally strengthened with CFRP plates was investigated and presented in this paper. Eight full-scale WSBs were tested under four-point bending up to failure. Seven beams were strengthened with CFRP plates bonded to the soffit of the beams and one beam was unstrengthened serving as control. Prior to strengthening, the beams were subjected to different levels of damaging by preloading to 30-95% of the beams' flexural capacity. One beam was fully damaged by preloading to failure and repaired before strengthening by replacing the crushed concrete. The data showed that the pre-damaged strengthened beams exhibited ultimate capacities up to 8% lower than those of the undamaged strengthened beams. However, the load carrying capacities of pre-damaged strengthened beams were more than those predicted by ACI 440 design guide, fib Bulletin 14, and JSCE design recommendations. Both fib Bulletin 14 and JSCE design recommendations gave very conservative predictions with average ratios of experimental to predicted ultimate capacity of 2.02 and 2.35, respectively. More accurate predictions were obtained by ACI 440 design guide as the corresponding ratio was 1.24. These results indicate that strong confidence and reliability can be placed in applying CFRP strengthening to structurally damaged WSBs.

O trabalho atual é um estudo epidemiológico que objetiva detectar a predominância da mastite subclínica e investigar os micróbios patogênicos principais do úbere no México ocidental. Com esta finalidade, foram utilizadas 2205 vacas leiteiras, representando 33 rebanhos de leiteiras mexicanas. Além dessas 2205 vacas, 752 animais com mastite foram diagnosticados, considerando-se que somente 2979 amostras do leite poderiam ser obtidas para a posterior investigação. Todas as 2979 amostras do leite foram submetidas ao teste da mastite de Califórnia (CMT) para diferenciar casos clínicos dos subclínicos, visto que 1996 amostras (67%) reagiram positivamente. Além dessas, 1087 amostras (54.5%) vieram das vacas que sofrem de casos clínicos de mastite. A identificação bacteriológica dos agentes causais revelou a presença dos Staphylococcus negativos para coagulase (CNS), S. aureus, S. agalactiae, outros spp. Streptococcal, Corynebacterium spp., e as bactérias de coliformes foram detectadas em 464 (15.6%), 175 (5.9%), 200 (6.8%), 109 (3.9%), 417 (14%) e em 123 (4.1%) dos 2927 quartos investigados; em 295 (15.4%), 118 (15.7%), 111 (14.8%), 95 (12.6%), 227 (30.2%) e em 109 (14.5%) das 752 vacas examinadas e, finalmente, em 33 (100%), 22 (66.7%), 19 (57.6%), 30 (90.1%), 30 (90.1%) e em 27 (81.8%) dos 33 rebanhos envolvidos, respectivamente.

The present work is a large epidemiological study aiming to detect the prevalence of subclinical mastitis and to investigate the major udder pathogens in Jalisco State, western Mexico. For this purpose, 2205 dairy cows, representing 33 Mexican dairy herds, were involved. Of 2205 cows, 752 mastitic animals were diagnosed and only 2,979 milk samples could be obtained for further investigation. All 2979 milk samples were subjected to California Mastitis Test (CMT) to differentiate clinical cases from subclinical ones where 1996 samples (67 %) reacted positively. Of these, 1087 samples (54.5%) came from cows suffering from clinical cases of mastitis. Bacteriological identification of the causative agents revealed the presence of a major group of pathogens including the Coagulase negative staphylococci (CNS), S.aureus, S.agalactiae, Corynebacterium spp. and Coliform bacteria which were detected in 464 (15.6%), 175 (5.9%), 200 (6.8%), 417 (14%) and 123 (4.1%) of the 2927 investigated quarters, 295 (15.4%), 118 (15.7%), 111 (14.8%), 227 (30.2%) and 109 (14.5%) of the 752 examined cows and in 33 (100%), 22 (66.7%), 19 (57.6%), 30 (90.1%) and 27 (81.8%) of the 33 herds involved, respectively. Other pathogens could be detected in the investigated milk samples such as S. dysgalactiae (0.4%), S.uberis (0.37%), Bacillus spp. (1%), Nocardia spp. (0.6%) und Candida spp. (0.1%). Meanwhile, others were present in a negligible ratio; including the Aerococcus viridans, and Enterococcus spp., Lactococcus lactis, S. bovis.