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Few studies have screened fresh orange juice for the presence of foodborne pathogens. This study therefore evaluated the microbiological quality and occurrence of Salmonella, Shigella, Escherichia coli, and diarrheagenic E. coli pathotypes (DEP) in fresh-squeezed orange juice purchased from street vendors in Morelia, Michoacan, Mexico. The general hygienic practices of street vendors were poor. All 100 samples analyzed were positive for aerobic mesophilic bacteria, with concentrations ranging from 2.41 to 6.03 log CFU/mL. A total of 90 (90%), 35 (35%), and 14 (14%) samples were positive for total coliforms, fecal coliforms, and E. coli, respectively, present with concentrations ranging from < 1 to 4.84 log CFU/mL, < 3 to > 1,100 MPN/mL, and < 3 to 210 MPN/mL, respectively. Salmonella was not detected in any of the samples, whereas Shigella sonnei was isolated from one sample. Two samples were positive for DEP; one harbored ETEC strains and the other STEC strains. Our results highlight the elevated risk for consumer health associated with the ingestion of fresh-squeezed orange juice.

Reproductive traits and natural mortality rate of cardinalfish females (Epigonus crassicaudus) were studied from samples collected onboard commercial fishing vessels, from 2012 to 2015, on the Chilean coast. The reproductive cycles of females analyzed thought gonadosomatic index (GSI) showed a maximum reproductive activity in austral fall, between March and May. Length (L50%) and age (A50%) at maturity, estimated using a macroscopic scale of the developed ovary, was 22.3 cm fork length (FL) and 9.3 years, respectively. Natural mortality (M) was estimated by two age-related methods. Using maximum age (tmax) M was estimated in 0.063 yr-1 and through age-at-maturity (A50%) in 0.15 yr-1. A potential bias in the reproductive study is discussed when a macroscopic maturity scale is used. Nevertheless, its usefulness is validated when funding is scarce, and time is limited. Although M uncertainty was not evaluated, the estimated range appears to be into the expected values to long-lived species. The life history parameters estimated in the present study can be used to evaluate possible time variability in maturity and M rates. Also, these results could be used in stock assessment analysis and to apply effective management measures in the fishery.

The slow-growing, nontuberculous mycobacterium Mycobacterium kumamotonense possesses two rRNA operons, rrnA and rrnB, located downstream from the murA and tyrS genes, respectively. Here, we report the sequence and organization of the promoter regions of these two rrn operons. In the rrnA operon, transcription can be initiated from the two promoters, named P1 rrnA and PCL1, while in rrnB, transcription can only start from one, called P1 rrnB. Both rrn operons show a similar organization to the one described in Mycobacterium celatum and Mycobacterium smegmatis. Furthermore, by qRT-PCR analyses of the products generated from each promoter, we report that stress conditions such as starvation, hypoxia, and cellular infection affect the contribution of each operon to the synthesis of pre-rRNA. It was found that the products from the PCL1 promoter of rrnA play a pivotal role in rRNA synthesis during all stress conditions. Interestingly, the main participation of the products of transcription from the P1 promoter of rrnB was found during hypoxic conditions at the NRP1 phase. These results provide novel insights into pre-rRNA synthesis in mycobacteria, as well as the potential ability of M. kumamotonense to produce latent infections.

The spatial and temporal variation of the early growth patterns (EGP) of anchoveta (Engraulis ringens), were analyzed and compared among three geographic areas, i.e., Northern zone (18–24°S); North-central zone (26–30°S) and Southern zone (33–42°S) off the Chilean coast over three years (i.e., 2015, 2016 and 2019). EGP were determined through otolith microstructure analysis for juveniles ranging from 2.0 to 12.0 cm in total length (TL), corresponding to ages from 28 to 187 days. The comparative growth analysis between the three study areas for the 2015, 2016 and 2019 cohorts showed significant differences in the Laird-Gompertz growth parameters and the absolute growth rate at the inflection point (0.67–1.11 mmd−1). A generalized additive models (GAM) was used to analyze changes in mean daily increment width profiles (IW) as related to the area, monthly cohort, sea surface temperature (SST) and Chlorophyll concentration (Chloa) as predictive variables. The GAM did not show significant difference in mean IW between northern and north-central areas (7.9 ± 3.9 vs 8.3 ± μm), although they significantly varied with respect the southern area, where the lower values of IW were found (5.6 µm). The GAM showed higher IW partial residuals when SST was above 14 °C and Chloa concentration was lower than 2 m gm−3. Overall results showed a high plasticity in the early growth pattern of E. ringens, indicating interannual and spatial variability, with SST playing a pivotal role across a wide latitudinal gradient off Chilean coast.

This study evaluated the microbiological quality and prevalence of Escherichia coli and diarrheagenic E. coli pathotypes (DEP) among fresh-squeezed orange juice from street vendors and their hygienic practices. Sixty orange juice stalls in Mexico City were visited, and 60 samples were purchased. Most (65%) of the street vendors had poor hygienic practices. Twelve (20%) prepared orange juice at the time of purchase, while the other stalls sold already-squeezed orange juice. All samples analyzed were positive for aerobic mesophilic bacteria, with limits ranging from 1 to 6.8 log CFU/mL. A total of 35 (58.3%), 27 (45%), and 5 (8.3%) samples were positive for total coliforms, fecal coliforms, and E. coli, respectively, present at concentrations ranging from < 3 to > 1100, < 3 to > 1100, and < 3 to 53 MPN/mL, respectively. Two samples harbored DEP at concentrations of 3.6 and 9.2 MPN/mL. Both samples harbored Shiga toxin-producing E. coli strains, positive for the Shiga toxin 2 (stx2) locus. Our results suggest that consumption of fresh-squeezed street-vended orange juice may pose a health risk for consumers, revealing the necessity to implement adequate hygiene and safety practices to protect the health of consumers.

Anchovy (Engraulis ringens) population units were analyzed in three zones off the coast of Chile: 1: Arica-Iquique, 2: Coquimbo and 3: Talcahuano-Valdivia from samples obtaineds during the 2012 spawning season. We used 50 left sagittae otoliths from each zone to perform a morphometric analysis, which included basic measurements, shape indexes and contour analysis (elliptical Fourier analysis). A MANOVA and Tukey multiple comparison analyses, applied on basic measures and shape indexes showed significant differences between zone 3 and zones 1 and 2. A classification by Canonical Discriminant analysis of elliptical Fourier harmonics, indicated significant differences among zones. It is concluded, therefore, that otolith shape analysis could be used to discriminate population units of Engraulis ringens. Better results were achieved using elliptic Fourier coefficients than using only shape indices.

The presence of insoluble aggregates of amyloid β (Aβ) in the form of neuritic plaques (NPs) is one of the main features that define Alzheimer’s disease. Studies have suggested that the accumulation of these peptides in the brain significantly contributes to extensive neuronal loss. Furthermore, the content and distribution of cholesterol in the membrane have been shown to have an important effect on the production and subsequent accumulation of Aβ peptides in the plasma membrane, contributing to dysfunction and neuronal death. The monomeric forms of these membrane-bound peptides undergo several conformational changes, ranging from oligomeric forms to beta-sheet structures, each presenting different levels of toxicity. Aβ peptides can be internalized by particular receptors and trigger changes from Tau phosphorylation to alterations in cognitive function, through dysfunction of the cholinergic system. The goal of this review is to summarize the current knowledge on the role of lipids in Alzheimer’s disease and their relationship with the basal cholinergic system, as well as potential disease-modifying therapies.

Age and growth parameters were estimated for the deep-sea cardinalfish (Epigonus crassicaudus) from sagittal otoliths collected between 2012 and 2015 onboard commercial fishing vessels from the South-east Pacific off Chile between 33°04′S and 41°46′S. Von Bertalanffy growth parameters (VBGP) were estimated from assumed annual otolith growth zone counts. The verification of the first annulus of sagittal otoliths was determined by examining in detail daily micro-increments. These data helped inform the interpretation of the annual growth zones from transverse otolith sections. The von Bertalanffy growth model estimated to length-at-age data were asymptotic length (L∞) of 34.1 cm fork length (FL), a growth coefficient (k) of 0.1 cm/year and a t-zero (t0) of −0.85. The maximum ages observed were 67 and 65 years for female and male fish, respectively.

The phenotypical variability in otolith shape of anchoveta (Engraulis ringens) was analysed in three zones (I, II and III) from north to south along the Chilean coast, using juvenile and adult fish. Generalised additive models were used to analyse shape indices and canonical discriminant analysis was used to analyse elliptical Fourier harmonics. The form factor and ellipticity indices varied significantly among the three zones, whereas roundness, circularity and rectangularity indices only showed differences between Zones I and III. Fourier reconstructed outlines for five ontogenetic stages suggested important differences among sampling zones, which were larger for sampling Zone III, where, at the same fish length, otoliths were smaller than those sampled in Zones I and II, at least at the pre-recruit stage. Elliptical Fourier descriptors showed significant differences among the three units, with a total percentage of correct classifications for juveniles of 89 and 74% for raw data and cross-validated cases respectively, compared with >85 and ∼65% respectively for adult fish. The results support the hypothesis that juveniles and adults of anchoveta have remained segregated throughout their entire, or at least a fraction of, their life cycle, mainly between the extreme northward and southward zones., The sampling for this study was performed as part of the hydroacousti recruitment survey of anchoveta and the Spawning Monitoring Project, funded by the Chilean Ministry of Economy, Promotion and Tourism (Asesoría Integral en Pesca y Acuicultura, ASIPA, grants 2015 and 2016). Morphological analyses were funded by the Chilean Fund for Fisheries and Aquaculture Research (Fondo de Investigación Pesquera y Acuícola, FIPA, grant 2015–22).

The present paper is an application of the ‘Projection Principle’ and the ‘Extended Projection Principle’ to an existential sentence of Spanish. With the purpose of, first, fulfi ll the subcategorization frames and, then, show the different subjects of the analyzed sentence, the types of null subjects (small-pro and big-PRO) are studied within the sentence and some of the aspects of the verbs and the verbal roots that compose it, so that the requirements posed by the mentioned principles are accomplished. Once this is done, certain phenomenon about the construction of the sentence which must be studied further are presented. El presente trabajo es una aplicación del ‘Principio de Proyección’ y del ‘Principio de Proyección Extendida’ a una oración existencial en español. Con el fin de, primero, saturar los marcos de subcategorización y, luego, señalar los distintos sujetos de la oración analizada, es que se revisan los tipos de sujetos vacíos (pro-pequeño y PRO-grande) en la oración y algunos aspectos de los verbos y las raíces verbales que la componen, de manera que se cumpla con los requisitos que plantean los dos principios mencionados. Hecho esto, se presentan ciertos fenómenos sobre la construcción de la oración que merecen estudios futuros.

The anchoveta (Engraulis ringens) plays a key role in the ecology of the Humboldt Current System and is of major economic importance; however, many aspects of its early life history are still poorly understood. In this study, an analysis of daily age and length patterns was carried out using the sagittal otoliths from wild larvae (0-0.2 cm standard length, LS ), pre-recruits (3-6 cm total length, LT ), recruits (7-12 cm LT ) and young adults (12-15 cm LT ). Additionally, variability in growth and age at recruitment (AR ) were evaluated for recruits caught in northern Chile in 1973, 1982, 2009, 2010, 2012, 2013, 2014 and 2015. The age-length relationship showed four allometric patterns that were well described by Laird-Gompertz models. The absolute growth rates at the inflexion point (GAR ) were 0.56, 0.75, 1.22 and 1.16 mm d-1 for larvae, pre-recruits, recruits and young adults, respectively. At the interannual scale, GAR values were always >1 mm d-1 (mean ± S.D. 1.37 ± 0.21 mm d-1 ; range 1.12-1.64 mm d-1 ), irrespective of the season of hatching (i.e. winter v. spring); additionally, in most cases, GAR values were reached before the second month of life (mean ± S.D. 50.47 ± 9.73 days) at c. 4 cm LT (mean ± S.D. 4.22 ± 0.29 cm). Mean AR was < 150 days (112 ± 29 days; range 75-149 days); in contrast, estimates of AR were higher and growth rates were lower in 1973, 1983 and 2000. These results demonstrate very fast growth and early AR of anchoveta in northern Chile, suggesting most fish are removed by the fisheries at very early ages. An evaluation of the implications of these results on stock assessment and management of this species is highly recommended.

Wild adult specimens of the Peruvian anchovy Engraulis ringens were captured and reared to validate the daily periodicity of otolith microincrement formation. The postcapture stress generated spontaneous spawning, making it possible to conduct a rearing trial on larvae first in an artificial nutrient-enriched system (ANES) for 52 days followed by an artificial feeding regime in a culture tank until day 115 post-hatch. Microincrements of the sagittal otoliths of sacrificed juveniles [mean ± S.D. total length (LT ) = 5·13 ± 0·37 cm, range 5-6 cm; c.v. = 7·5%] showed very distinct light and dark zones. The slope of the relationship between the total number of increments after the hatch check and days elapsed after hatching was not significantly different from 1. The transfer from ANES to the artificial feeding regime induced a mark in the sagittal otoliths. The number of microincrements after this induced mark coincided with the number of days elapsed after the transfer date. In parallel experiments, adult E. ringens (mean ± S.D. LT = 14·92 ± 0·55 cm, range 13-16 cm) were exposed to one of two fluorescent marking immersion treatments with either alizarin red S (ARS; 25 mg l(-1) per 6 h) or oxytetracycline hydrochloride (OTC; 200 mg l(-1) per 10 h). The microincrements between fluorescent bands were distinct, ranging from 0·89 to 2·75 µm (mean ± S.D. =1·43 ± 0·28 µm; c.v. = 32%) and from 0·71 to 2·89 µm (1·53 ± 0·27 µm; c.v. = 35%) for ARS and OTC, respectively. The relationship between the number of microincrements between marks and the number of elapsed days for ARS and OCT treatments indicated that there was a significant correspondence between the number of increases observed and the number of days. Hence, daily microincrements of otoliths of E. ringens are likely to be formed in juveniles and adults under natural conditions.

Age, growth, maturity, and natural mortality estimates were made for chub mackerel (Scomber japonicus Houttuyn, 1782) captured off the Chilean Pacific coast. The von Bertalanffy growth parameters for combined sexes from north and central-south areas were L [infinity] = 36.9 cm, k = 0.22 yr-1, and t 0 = -1.35 yrs, and L[infinity] = 40.0 cm, k = 0.23 yr-1, and t 0 = -1.34 yrs, respectively. The spawning period in the northern area ranged from November to February of each year; it was restricted to January and February in the central-south area. The size at maturity (Lm 50%) estimated for the north and central south areas, respectively, were 25.1 and 29.6 cm fork length (FL) in males, and 25.9 and 28.1 cm FL in females. Natural mortality was similar in the two areas: 0.45 yr-1 in the north and 0.46 yr -1 in the central-south region. Results support the existence of two stocks off Chile's southeastern coast.

Growth parameters (L∞, K, and t0) and natural mortality of the Patagonian sprat (Sprattus fuegensis) Chiloé inland sea were estimated. This area corresponds to the northern limit of the species distribution in the South Pacific Ocean. A total of 1,584 otolith were analyzed between July 2005 and December 2006. A covariance analysis ruled out significant differences (P = 0.654) in the otolith size-fish length relationship between males and females. The otoliths showed high monthly proportion of hyaline edge type in August 2005 and from July to October 2006. The hyaline band formation from mid-winter to spring coincided with the breeding season extending from September to December. This suggests an annual periodicity of annuli formation, likely as a consequence of channeling energy into reproduction. The growth parameters were L∞= 17.71 cm; K = 0.78 yr-1; and t0 = -0.46 yr, while the maximum observed age was 6 years. Natural mortality given growth parameters and species maturity, was estimated at 1.0 yr-1. The modal decomposition of monthly length distribution, analyzed by a statistical-numerical algorithm (MIX approach) gave similar results to those obtained from otolith readings.

We use a novel proxy (growth rates of long-lived deep water fish, orange roughy) to reconstruct inferred water temperatures of intermediate water masses in both Northern and Southern Hemispheres since the mid-1800s. The data are consistent with instrumental records showing long-term warming in the Northern Hemisphere but also indicate decadal variability of intermediate depth temperatures that is coherent across the two hemispheres. This variability correlates with the dominant subpolar annular mode in each hemisphere and implies a bihemispheric oceanic response to external forcing that influences the properties of intermediate depth water masses.

Recent studies using otolith microstructure analysis have suggested that the duration of the juvenile stage in anchoveta (Engraulis ringens) is shorter than previously suspected, which suggests that the ages being entered into the traditional age-based stock assessment are incorrect. However, the interpretation of young pelagic fish otoliths remains problematic. To clarify the age interpretation of larval and juvenile E. ringens, newly hatched larvae were reared in a quasi-natural environment for periods of up to 103 days. The sagittal otoliths were subsequently examined and measured by international otolith experts in a double-blind workshop study. The young anchovy could be aged both accurately and precisely using otolith microstructure, after measures were taken to correct for unresolvable increments formed immediately after hatch. The presence of a fast-growth transition zone characterised by either considerable splitting or subdaily increments or both was confirmed. This study confirms the hypothesis of rapid growth and young age through the juvenile stage for anchoveta, suggesting that a critical appraisal of the annual age determinations used as the basis for anchoveta stock assessment is warranted. The otolith interpretation principles outlined in this study may apply broadly across many small pelagic fish species.

Las verduras se asocian frecuentemente con brotes de enfermedades gastrointestinales en todo el mundo. El cilantro se consume comúnmente en estado crudo (ensaladas verdes), en México como en otros países, y se ha asociado con brotes de infecciones por Salmonella (ICMSF, 2011). Hay poca información sobre la calidad y seguridad del cilantro en México (López-Saucedo et al., 2003). El objetivo de este trabajo fue medir la presencia de bacterias coliformes (CB), coliformes fecales (CF), E. coli genérica, seis patotipos de E. coli (PEC) y cepas de Salmonella múlti-resistentes a antibióticos en cilantro. El 100% de las muestras fueron positivas para CB, el 97% para CF, el 47% para E. coli genérica, 4% para los PEC y el 23% para Salmonella. Los PEC identificados incluyen E. coli enterotoxigénica (1%) y E. coli productora de toxina Shiga (3%). Se aislaron 31 cepas de Salmonella en 23% de las muestras de cilantro. Todas las cepas aisladas mostraron resistencia a al menos 3 antibióticos. La prevención y mitigación del riesgo requiere la aplicación de Buenas Prácticas Agrícolas y Buenas Prácticas de Manufactura en todo el proceso de producción del cilantro, desde la cosecha hasta el minorista. Además, es necesario aplicar un tratamiento eficaz de desinfección en el cilantro antes de su consumo.

Licandeo, R., Cerna, F., and Céspedes, R. 2007. Age, growth, and reproduction of the roughskin skate, Dipturus trachyderma, from the southeastern Pacific. ICES Journal of Marine Science, 64: 141–148. Age, growth, and reproductive parameters of the roughskin skate, Dipturus trachyderma, in the southeastern Pacific are reported. Age was estimated by counting the growth rings of thin sections of vertebral centra from 201 fish (61–253 cm total length, LT). No systematic ageing bias was observed, and the precision of growth ring counts indicated a high level of reproducibility. Marginal increment analysis supported the hypothesis of annual deposition of growth rings, which form during winter. The oldest female and male were 26 and 25 y, respectively. Von Bertalanffy parameters for combined sexes based on length-at-age data were L∞=257.7 cm LT, K=0.081 y−1 and t0=–1.363 y. Skates from the southernmost areas attained a larger mean size than those from more northern areas, and females reached a larger adult size than males. Males began the maturation process at ∼186 cm LT, indicated by the abrupt enlargement of the claspers. Developed oviducal glands, uteri, and ovaries indicated that females began to mature at 200 cm LT. The length and age at which 50% of the population matured were 215 cm LT and 17 y for females and 195 cm LT and 15 y for males. The youngest mature female and male D. trachyderma were 15 and 13 y, respectively. The ovarian fecundity ranged from 28 to 68 follicles. Females carrying egg cases were found in March and July. Dipturus trachyderma is slow-growing, long-lived, attains large size, matures late, and has low fecundity, life history characteristics that make it highly susceptible to exploitation.

The Peruvian anchovy (Engraulis ringens) is a resource of considerable economic importance, whose stock unit is distributed between 16°00′S and 24°00′S and is shared between Chile and Peru. In the present study, daily growth patterns of juvenile and adult Peruvian anchovies in northern Chile were determined using micro-increments of sagittal otoliths for the recruitment and fishery seasons of 2009 and 2010. A characteristic feature was the existence of very distinctive daily micro-increments, through which a complete sequence of micro-increments was obtained from the primordium to otolith edge for juveniles (7.5–12-cm total length (TL)) and adults (12.5–18.0cm TL), whose ages were in the range 56–166 and 137–409 days respectively. Hatch dates extended from July 2009 to July 2010, where juveniles recruited to a fishery in a given month were the survivors of a spawning that had occurred approximately 3–4 months before. A Laird–Gompertz model fitted to length-at-age data for juveniles estimated maximum instantaneous growth rates that ranged from 0.98 to 1.57mm day–1, whereas overall mean individual growth rates back-calculated for the age range of juveniles ranged from 0.65 to 1.02mm day–1. The von Bertalanffy seasonal parameters estimated through the entire life history showed high growth, with a growth coefficient K=1.1 and mean length at the first year of 16.3cm TL. Consequently, E. ringens in northern Chile seems to maximize growth in the first year of life.

Una especie de Clupeiformes que ha sido habitual en las capturas de la flota pesquera artesanal que opera en el mar interior de Chiloe, Chile, ha sido confundida con la sardina comun (Strangomera bentincki) y la sardina espanola (Sardinops sagax musica), cuyas distribuciones geograficas en esta area marcan su limite austral. Mediante un analisis de morfometria y recuentos de estructuras duras de siete ejemplares capturados en julio de 2005 y provenientes del area de pesca de Quicavi, Chiloe (42o17'S-73o22'W), se determino, que correspondian a seis Sprattus fuegensis (Jenyns 1842) (sardina fueguina), y que ella estaria presente hegemonicamente en las capturas del mar interior de Chiloe; en la X Region administrativa de Chile. Basado en la captura de especimenes de S. fuegensis obtenidos en las cercanias de la Isla Guar, al norte de Calbuco en octubre de 2005, se realizo una breve descripcion de otolitos y una comparacion del diametro longitudinal del primer anillo hialino entre ambas sardinas, mediante el uso del test no parametrico de Mann-Withney; del mismo modo, se comparo la relacion longitud del pez con el diametro del otolito para ambas sardinas utilizando un ANCOVA. El presente estudio confirma la presencia de S. fuegensis en el oceano Pacifico y senala el limite norte de su distribucion en el area del Seno de Reloncavi. Este redescubrimiento revela que durante el periodo de marzo a diciembre de 2005 esta especie sostuvo una actividad extractiva, que viene ocurriendo desde hace algunos anos, y que no se ha reflejado oficialmente en las estadisticas de pesca, con desembarques artesanales del orden de las 18 mil toneladas/ano. Esto significa que la unica pesqueria de clupeidos de aguas interiores es sostenida mayoritariamente por S. fuegensis y pone en perspectiva la necesidad de evaluar con cautela los trabajos tecnicos y recopilacion de informacion en las aguas interiores de Chiloe.

The shortfin mako, Isurus oxyrinchus, is a large pelagic shark with a widespread global distribution. However, very little is known about most aspects of this species for the south-eastern Pacific. In the present paper, the age and growth parameters of the shortfin mako, caught by Chilean swordfish longline fisheries from 2004 to 2005, are reported. Ages were estimated by counting band-pairs from sections of vertebral centra from 547 individuals, ranging from 76 to 330 cm in total length (TL). Trends in the proportion of opaque edges for all ages combined and grouped into ages 0–6 and 7–26 years indicated that they are formed during summer and showed that annually, one band-pair is formed in the vertebrae of shortfin makos. Modal-progression analysis was used to verify the first three age classes (ages 0–2 years). For both sexes, the oldest estimated age was 25+ years. Von Bertalanffy growth parameters were estimated at L∞ = 325.29 cm TL, K = 0.076 year–1 and t0 = –3.18 years for females and L∞ = 296.60 cm TL, K = 0.087 year–1 and t0 = –3.58 years for males. The results indicated that this species is highly vulnerable to exploitation and, thus, urgent conservation measures are required.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Hot land region is located in western central Mexico in the state of Michoacán’s has a vast production of milk and dairy products, however the cheeses is not evaluated for microbiological quality and the occurrence of foodborne pathogens, therefore the aims of this study were (i) to assess the microbiological quality of fresh cheeses and adobera cheeses produce in six artisanal factories located in the hot land region of Michoacan Mexico and (ii) to evaluate the occurrence of human pathogens, S. aureus, Salmonella spp, E. coli, L. monocytogenes, and Mycobacterium spp. in the samples. Six different artisan cheese factories were selected, three were located in Buenavista, two in Tepalcatepec and one in Apatzingán. From November 2018 to March 2019, a total of 30 unpasteurized fresh cheeses and 30 unpasteurized adobera cheeses were collected. Five fresh cheeses and five adobera cheeses were collected from each one of the six artisanal factories. All samples collected were stored in a cold container at 4 °C and transported to the laboratory. El estado de Michoacán en México es una de las regiones más diversas en actividades agropecuarias, la región de tierra caliente ubicada al suroeste del estado, cuenta con una vasta producción de lácteos y de sus derivados; sin embargo, las características meteorológicas y de producción generan puntos críticos de contaminación en el producto, y es debido a esta situación que los objetivos de esta investigación fue evaluar la calidad microbiológica y la búsqueda de bacterias patógenas en quesos artesanales de tipo fresco y adobera. Para este estudio el área seleccionada fueron tres municipios en el estado de Michoacán, los cuales se encuentran en regiones productoras de queso. Se seleccionaron seis fábricas de queso artesanal, tres ubicadas en Buenavista, dos en Tepalcatepec y una en Apatzingán. En el periodo comprendido entre noviembre de 2018 y marzo de 2019, se colectaron 30 quesos frescos y 30 quesos adobera, cinco quesos frescos y cinco de adobera de cada fábrica. Todas las muestras colectadas se almacenaron en un recipiente frío a 4 °C y se transportaron al laboratorio.