BACKGROUND STAPHYLOCOCCUS AUREUS PRODUCES 11 SEROTYPES OF ENDOTOXINS THAT MAY CAUSE FOOD POISONING. AIM TO DETERMINE THE PREVALENCE OF TYPE A ENTEROTOXIGENIC STAPHYLOCOCCUS AUREUS CARRIAGE AMONG FOOD SERVICE WORKERS IN CHILLAN, CHILE. MATERIAL AND METHODS PHARYNGEAL SWABS WERE OBTAINED FROM 100 FOOD SERVICE WORKERS AND WERE CULTURED IN AGAR PLATES. AFTER IDENTIFYING THE PRESENCE OF STAPHYLOCOCCUS AUREUS, DNA WAS EXTRACTED TO IDENTIFY TYPE A TOXIN BY CONVENTIONAL PCR. RESULTS THIRTY EIGHT PERCENT OF SAMPLES WERE COLONIZED WITH STAPHYLOCOCCUS AUREUS. AMONG THESE, 26% WERE TOXIN A PRODUCERS. CONCLUSIONS HALF OF THE SAMPLED WORKERS CARRIED STAPHYLOCOCCUS AUREUS AND A QUARTER OF THESE PRODUCED TYPE A ENTEROTOXIN. KEY WORDS STAPHYLOCOCCUS AUREUS; ENTEROTOXINS; FOODBORNE DISEASES

BACKGROUND STAPHYLOCOCCUS AUREUS PRODUCES 11 SEROTYPES OF ENDOTOXINS THAT MAY CAUSE FOOD POISONING. AIM TO DETERMINE THE PREVALENCE OF TYPE A ENTEROTOXIGENIC STAPHYLOCOCCUS AUREUS CARRIAGE AMONG FOOD SERVICE WORKERS IN CHILLAN, CHILE. MATERIAL AND METHODS PHARYNGEAL SWABS WERE OBTAINED FROM 100 FOOD SERVICE WORKERS AND WERE CULTURED IN AGAR PLATES. AFTER IDENTIFYING THE PRESENCE OF STAPHYLOCOCCUS AUREUS, DNA WAS EXTRACTED TO IDENTIFY TYPE A TOXIN BY CONVENTIONAL PCR. RESULTS THIRTY EIGHT PERCENT OF SAMPLES WERE COLONIZED WITH STAPHYLOCOCCUS AUREUS. AMONG THESE, 26% WERE TOXIN A PRODUCERS. CONCLUSIONS HALF OF THE SAMPLED WORKERS CARRIED STAPHYLOCOCCUS AUREUS AND A QUARTER OF THESE PRODUCED TYPE A ENTEROTOXIN.

WE DESCRIBE FOUR METHODS TO CAPTURE KELP GULLS (LARUS DOMINICANUS) AND ESTIMATEDITS EFFICIENCY IN TALCAHUANO, CHILE. THE FOUR METHODS WERE: (I) HAND-NET, (II) SLIDING BOW LASSO,(III) PLIABLE ARCH, AND (IV) ADAPTED BAL-CHATRI. THE MOST SUCCESSFUL METHOD WAS THE ADAPTEDBAL-CHATRI FOLLOWED BY THE SLIDING BOW LASSO. THE HAND-NET AND THE PLIABLE ARCH WERE THE LEASTEFFICIENT METHODS. THE EFFICIENCY OF THESE METHODS DIMINISHED AFTER THE FIRST CAPTURE SEEMINGLYDUE TO RAPID LEARNING BY THE GULLS. WE ALSO COMMENT ON THE GULL?S BEHAVIORAL DISPLAYS DURINGCAPTURE EVENTS.

A RYEGRASS FERTILIZATION POT EXPERIMENT WAS CARRIED OUT WITH VOLCANIC SOIL OF CENTRAL CHILE DURING THE 2009-10 SEASON USING TWO COMMERCIAL COMPOSTS (VITAFERT AND BIOSTABILIZED SWINE MANURE) AND CONVENTIONAL FERTILIZATION WITH TOTAL NITROGEN DOSES OF 135 MG KG?1. WE SUCCESSIVELY APPLIED COMPOST TEA PREPARED WITH VITAFERT COMPOST AND SET UP EIGHT TREATMENTS: CONTROL WITHOUT FERTILIZATION (C), CONTROL WITH COMPOST TEA IN EACH IRRIGATION (C1), CONTROL WITH COMPOST TEA EVERY SECOND IRRIGATION (C2), CONVENTIONAL FERTILIZATION (CF), BIOSTABILIZED SWINE MANURE WITHOUT COMPOST TEA (B1), BIOSTABILIZED SWINE MANURE WITH COMPOST TEA IN EACH IRRIGATION (B2), VITAFERT WITHOUT COMPOST TEA (V1), AND VITAFERT WITH COMPOST TEA IN EACH IRRIGATION (V2). THE CROP WAS ESTABLISHED IN DEC. 2009 AND MAINTAINED UNTIL MAY 2010; FOUR CUTTINGS WERE CARRIED OUT AT 5 CM ABOVEGROUND ON PLANTS AVERAGING A 20-CM HEIGHT. DRY MATTER (DM) PRODUCTION AND N CONCENTRATION WAS DETERMINED IN EACH CUTTING. RELATIVE DM PRODUCTION, TOTAL AND FOR EACH CUTTING, N EXTRACTION, AS WELL AS APPARENT EFFICIENCY OF N RECOVERY (AENR) IN THE FERTILIZED TREATMENTS WERE DETERMINED. RESULTS INDICATED THAT THE HIGHEST TOTAL DM PRODUCTION WAS OBTAINED WITH CF, B1, AND B2; AND IT WAS MAINLY CONCENTRATED IN THE FIRST CUTTING. ADDING COMPOST TEA TO THE SOIL WITHOUT FERTILIZATION DID NOT AFFECT DM PRODUCTION WHEN COMPARED TO THE CONTROL, BUT IT HAD A POSITIVE EFFECT ON THE TREATMENTS WITH COMMERCIAL COMPOSTS. THE HIGHEST EXTRACTION OF TOTAL ACCUMULATED N WAS OBTAINED WITH CF AND B2. THE HIGHEST AENR IN THE FERTILIZED TREATMENTS WAS ACHIEVED IN CF (69%), B1 (54%), AND B2 (68%). RESULTS INDICATE THAT THERE IS A POSITIVE EFFECT OF COMPOST TEA WHEN RELATIVELY SOLUBLE CARBON SOURCES, SUCH AS NUTRIENT AMENDMENTS, ARE USED BEFORE. IN TURN, USING COMPOST TEA IN UNAMENDED SOIL HAD NO EFFECT ON THE EVALUATED PARAMETERS.

THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE PRESENCE OF CRONOBACTER SAKAZAKII AND MICROBIOLOGICAL PARAMETERS IN DAIRY PRODUCTS ASSOCIATED WITH A FOOD ALERT. NINETY DAIRY PRODUCT SAMPLES WERE ANALYZED, INCLUDING SEVEN COMMERCIAL BRANDS AND TWO PRODUCT TYPES (LIQUID AND POWDERED) FROM FOUR COUNTRIES. AEROBIC PLATE COUNT (APC) AND ENTEROBACTERIACEAE COUNT WERE PERFORMED ACCORDING TO CHILEAN STANDARDS. CRONOBACTER SPP. AND C. SAKAZAKII WERE IDENTIFIED BY POLYMERASE CHAIN REACTION REAL TIME AMPLIFICATION OF RPOB AND CGCA GENES AND THE GENOTYPE BY MULTILOCUS SEQUENCE TYPING. EIGHTY-EIGHT PERCENT OF DAIRY PRODUCTS SHOWED APC HIGHER THAN THE DETECTION LIMIT. FIFTY PERCENT OF LIQUID COMMERCIAL BRAND SAMPLES CONTAINED APC: 2.6, 2.3, 1.1, AND 2.9 CFU/ML IN BRANDS A, C, E, AND G, RESPECTIVELY. RESULTS FOR POWDERED COMMERCIAL BRANDS WERE 3.0, 3.6, AND 5.7 CFU/G IN BRANDS B, D, AND F, RESPECTIVELY. MAXIMUM COUNT (5.7 CFU/G) OCCURRED IN BRAND F DAIRY PRODUCT MANUFACTURED IN CHILE. ENTEROBACTERIACEAE WERE FOUND IN 55% OF THE SAMPLES, 64% IN LIQUID AND 51% IN POWDERED COMMERCIAL BRANDS. IN 50% OF BRANDS B, D, AND E, SAMPLES CONTAINED 2.9, 2.8, AND 2.7 LOG CFU/G, RESPECTIVELY. ONLY LIQUID COMMERCIAL BRANDS FROM THE UNITED STATES HAD ENTEROBACTERIACEAE VALUES BETWEEN 0.1 AND 4.5 CFU/ML. SEVENTEEN SUSPICIOUS STRAINS WERE ISOLATED AND NINE WERE IDENTIFIED AS ENTEROBACTER SPP. ONLY EIGHT SUSPICIOUS STRAINS FROM FOUR POWDERED COMMERCIAL BRANDS (CHILE AND SINGAPORE) WERE CONFIRMED AS C. SAKAZAKII BY RPOB AND CGCA GENE AMPLIFICATION AND FUSA SEQUENCING. C. SAKAZAKII PREVALENCE IN THE ANALYZED SAMPLES WAS 8.8%. THERE WERE 11% OF POWDERED MILK BRANDS THAT CONTAINED APC BETWEEN 4.0 AND 4.7 LOG CFU/G AND 55% OF THE SAMPLES CONTAINED ENTEROBACTERIACEAE. C. SAKAZAKII WAS FOUND IN DAIRY PRODUCTS MANUFACTURED IN CHILE AND SINGAPORE. ON THE BASIS OF THIS INFORMATION, THE CHILEAN MINISTRY OF HEALTH (RSA) DECREED A NATIONAL AND INTERNATIONAL FOOD ALERT AND RECALLED ALL THE PRODUCT BATCHES THAT RES

THE ACCUMULATION OF PLASTIC WASTE AND INFECTIOUS DISEASES HAS LED THE SCIENTIFIC COMMUNITY TO SEARCH FOR NEW MATERIALS TO MAKE NANOCOMPOSITES BIOFILMS. WITH THE HELP OF NANOTECHNOLOGY, THE MATERIALS THAT MAKE UP THE NEW NANOCOMPOSITES BIOFILM CAN BE MANIPULATED, ACHIEVING AN IMPROVEMENT IN ITS MECHANICAL PROPERTIES AND GRANTING ANTIMICROBIAL POWERS. BIOFILMS BASED ON ELECTROSPUN FIBERS AS A BARRIER MATERIAL CAN PROTECT AGAINST INFECTIOUS MICROORGANISMS. FOR THESE APPLICATIONS, THE ELECTROSPINNING METHOD ALLOWS THE ENCAPSULATION OF ACTIVE AGENTS IN THE POLYMERIC FIBERS. THIS ARTICLE PRESENTS THE DEVELOPMENT OF A NANOCOMPOSITES BIOFILM WITH POTENTIAL USE AS AN ANTIMICROBIAL BARRIER, WHICH INCORPORATES POLYLACTIC ACID MICROFIBERS WITH ACTIVE AGENTS. AMONG THEM, COPPER IONS SUPPORTED ON CHILEAN NATURAL ZEOLITE NANOPARTICLES AND REINFORCED WITH ACETYLATED CELLULOSE NANOFIBERS. THE STUDY BEGINS WITH OBTAINING CELLULOSE NANOFIBERS THROUGH MECHANICAL METHODS. NANOFIBERS WERE ACETYLATED TO ENSURE ADEQUATE DISPERSION IN THE POLYMER MATRIX AND TO IMPROVE THE MECHANICAL PROPERTIES OF BIOFILMS. POLYMERS AND NANOPARTICLES WERE INCORPORATED INTO BIOFILMS THROUGH A DUAL CONFIGURATION (SIMULTANEOUS INJECTION) ELECTROSPINNING STAGE.

THIS RESEARCH EVALUATED THE CONTRIBUTION OF NANOCOMPOSITE FILMS BASED ON DIFFERENT CONCENTRATIONS OF NZH-CU (1%, 2%, AND 3%) TO THE MICROBIOLOGICAL, ORGANOLEPTIC, AND PHYSICOCHEMICAL CHARACTERISTICS OF PACKED CHICKEN BREAST MEAT. ANALYSIS OF SOME MEAT QUALITY TRAITS, SUCH AS MICROBIOLOGICAL, CHEMICAL, AND PHYSICAL, WERE CONDUCTED ON A LABORATORY SCALE. FOR THIS, SMALL SQUARES OF CHICKEN BREAST MEAT, WEIGHING APPROXIMATELY 10 G, WERE ASEPTICALLY WRAPPED WITH RECTANGULAR PIECES OF 5 × 10 CM PLA-NZH-CU NANOCOMPOSITE FILMS, WHICH WERE STORED AT 4 °C FOR 20 DAYS. THE MICROBIOLOGICAL RESULTS INDICATED EFFICIENT ANTIBACTERIAL ACTIVITY (AT ANY NZH-CU CONCENTRATION IN THE NANOCOMPOSITE FILMS) ON THE TOTAL VIABLE COUNT OF GROUPS OF PSYCHROPHILES, AEROBIC MESOPHILES, ENTEROBACTERIACEAE, AND SALMONELLA SPP. UNTIL DAY 10 OF STORAGE (P < 0.05). NO SIGNIFICANT CHANGES WERE OBSERVED IN THE ORGANOLEPTIC (COLOR) AND PHYSICOCHEMICAL QUALITIES (TEXTURE, WEIGHT, PH, AND ACIDITY) UNTIL DAY 10 OF STORAGE AT 4 °C (P < 0.05). THE ANALYSIS OF THE EXPERIMENTAL TESTS CARRIED OUT DETERMINED THAT THE PLA-NZH-CU NANOCOMPOSITE FILMS PLAYED AN EFFECTIVE ROLE IN THE BACTERIAL SAFETY OF THE PACKAGED CHICKEN. IT WAS CONCLUDED THAT THE NZH-CU NANOCOMPOSITE FILMS, AT ALL CONCENTRATIONS TESTED, EXTENDED THE SHELF LIFE OF THE CHICKEN BREAST MEAT FOR UP TO 10 DAYS IN A REFRIGERATOR AT 4 °C.

POLYMERASE CHAIN REACTION CONFIRMED THAT TWO GULL SPECIES IN TALCAHUANO, CHILE, SHED SALMONELLA. FECAL SAMPLES FROM RESIDENT LARUS DOMINICANUS HAD PREVALENCES OF 51.2% FOR SALMONELLA SPP. AND 26.3% FOR SALMONELLA ENTERITIDIS. PREVALENCES IN SAMPLES FROM MIGRATORY LEUCOPHAEUS PIPIXCAN WERE 75% AND 30% RESPECTIVELY. RISKS TO PUBLIC HEALTH MAY EXIST.

STAPHYLOCOCCUS AUREUS ES UNA BACTERIA GRAM POSITIVA PRODUCTORA ENTEROTOXINAS ESTAFILOCÓCICAS, RESPONSABLES A NIVEL MUNDIAL DE BROTES POR INTOXICACIÓN ESTAFILOCÓCICA. DETERMINAR LA GENOTIPIFICACIÓN Y PREVALENCIA DE STAPHYLOCOCCUS AUREUS ENTEROTOXIGÉNICO TIPO B, C, D Y E EN FROTIS NASOFARÍNGEOS DE MANIPULADORES DE ALIMENTOS DE CHILE. ESTE ESTUDIO SE REALIZÓ EN UNA MUESTRA DE 100 MANIPULADORES DE ALIMENTOS DE SERVICIOS DE ALIMENTACIÓN DE CHILLÁN. REALIZANDO EN UNA PRIMERA ETAPA, PREVIA FIRMA DE CONSENTIMIENTO INFORMADO, MUESTREO NASOFARÍNGEO EN LOS LUGARES DE TRABAJO. LAS MUESTRAS SE TRASLADARON A 4°C, PARA LUEGO SER INOCULADAS POR 48 HORAS A 37 °C EN PLACAS AGAR BAIRD PARKER. POSTERIOR A LAS PRUEBAS CONFIRMATIVAS DE CATALASA Y COAGULASA PARA STAPHYLOCOCCUS AUREUS, SE REALIZÓ EXTRACCIÓN DE ADN Y POSTERIOR IDENTIFICACIÓN MOLECULAR DE ENTEROTOXINA TIPO B, C, D Y E, MEDIANTE LA AMPLIFICACIÓN POR PCR CONVENCIONAL. EL 38% DE LA MUESTRA ESTABA COLONIZADA POR STAPHYLOCOCCUS AUREUS. DEL TOTAL DE PORTADORES DE LA BACTERIA SE IDENTIFICÓ QUE EL 28,9% PRODUCÍAN LA ENTEROTOXINA TIPO B Y EL 7,9% PRODUCÍAN LA ENTEROTOXINA TIPO E, DE ESTOS UN 2,6% ERA PRODUCTOR DE AMBAS ENTEROTOXINAS. NO SE DETECTÓ PRESENCIA DE LAS ENTEROTOXINAS C Y D.

IN ORDER TO PROVIDE TOOLS FOR FUTURE HEALTH-BASED MONITORING PROGRAMS, WE DEVELOPED REFERENCE INTERVALS FOR HEMATOLOGY AND PLASMA BIOCHEMISTRY AND PARTITIONED DATA FOR SEX AND SEASON (WINTER AND AUTUMN). NINETY-ONE PHYSICALLY HEALTHY KELP GULLS (LARUS DOMINICANUS) WERE SAMPLED IN THE CITY OF TALCAHUANO, CHILE, DURING WINTER (JULY-SEPTEMBER) OF 2007, AUTUMN (APRIL-JUNE) AND WINTER OF 2008, AND AUTUMN OF 2009. AFTER BLOOD SAMPLING, THE KELP GULLS WERE EUTHANIZED BY CERVICAL DISLOCATION. PACKED CELL VOLUME (PCV), HEMOGLOBIN, TOTAL PLASMA PROTEIN (TPP), AND COMPLETE BLOOD COUNT WERE PERFORMED. ALANINE AMINO TRANSFERASE, GAMMA-GLUTAMYL TRANSPEPTIDASE, LACTATE DEHYDROGENASE, ALKALINE PHOSPHATASE (ALP), CREATININE, UREA, CALCIUM, PHOSPHORUS, AND URIC ACID WERE ANALYZED. NO SIGNIFICANT DIFFERENCES WERE FOUND BETWEEN SEXES (P>0.05). WHEN A COMPARISON WAS MADE BETWEEN THE TWO SEASONS, THE VALUES OF PCV, TPP, WHITE BLOOD CELL, HETEROPHILS, EOSINOPHILS, AND MONOCYTES WERE SIGNIFICANTLY HIGHER IN WINTER THAN IN AUTUMN (P

HEMATOLOGICAL AND BIOCHEMICAL PARAMETERS ARE USED TO ASSESS THE HEALTH OF BIRDS AND TO SUPPORT CONSERVATION PLANS FOR THREATENED SPECIES, SUCH AS THE ANDEAN CONDOR (VULTUR GRYPHUS). WE STUDIED 22 CAPTIVE ANDEAN CONDORS FROM THE REHABILITATION CENTER FOR RAPTORS OF THE UNIÓN DE ORNITÓLOGOS OF CHILE TO DETERMINE REFERENCE VALUES. WE MEASURED PACKED CELL VOLUME, TOTAL PLASMA SOLIDS, AND TOTAL AND DIFFERENTIAL LEUKOCYTE COUNTS; WE ANALYZED ASPARTATE AMINOTRANSFERASE, GAMMA-GLUTAMYL TRANSPEPTIDASE, LACTATE DEHYDROGENASE, ALKALINE PHOSPHATASE, CREATINE KINASE, CREATININE, CALCIUM, INORGANIC PHOSPHORUS, AND URIC ACID. WE FOUND NO BLOOD PARASITES AND NO SIGNIFICANT DIFFERENCES BETWEEN SEXES (P > 0.05). OUR RESULTS ESTABLISH A BASELINE FOR HEMATOLOGICAL AND SERUM BIOCHEMISTRY PARAMETERS FOR THE ANDEAN CONDOR.

THE USE OF MANURE-BASED ORGANIC SOIL AMENDMENTS IS COMMON IN COUNTRIES WITH FOOD ANIMAL PRODUCTION. A TWO-SEASON FIELD STUDY WAS CARRIED OUT IN CENTRAL CHILE TO EVALUATE THE EFFECT OF DIFFERENT POULTRY LITTER (PL) AND PIG COMPOST (PC) RATES (7.5, 10.0, 12.5, AND 15.0 MG HA?1FOR EACH AMENDMENT) COMBINED WITH DIFFERENT NITROGEN (N) RATES (0, 100, 200, AND 300 KG HA?1) ON DRY MATTER (DM), GRAIN PRODUCTION, AND MACRONUTRIENT CONCENTRATION IN CORN (ZEA MAYS L.) PRODUCED DURING THE 2008?2009 (PL) AND 2009?2010 (PC) SEASONS. THE SOIL WAS CLAY LOAM. ORGANIC AMENDMENTS WERE APPLIED BEFORE SOWING, WHEREAS INORGANIC N (UREA) WAS APPLIED AT THE 6-LEAF STAGE (V6). WHEN PL WAS COMBINED WITH N, DM PRODUCTION RANGED BETWEEN 21.44 AND 31.01 MG HA?1 AND GRAIN YIELD WAS BETWEEN 12.76 AND 17.86 MG HA?1. WHEN PC WAS COMBINED WITH N, DM PRODUCTION VALUES WERE BETWEEN 21.07 AND 26.18 MG HA?1 AND GRAIN YIELD WAS BETWEEN 14.01 AND 17.14 MG HA?1. RESULTS INDICATE THAT APPLYING A COMBINATION OF PL AND N IMPROVED DM PRODUCTION, BUT APPLYING A COMBINATION OF PC AND N DID NOT AFFECT THIS PARAMETER. GRAIN PRODUCTION WAS ONLY AFFECTED BY INCREASING N RATES. APPLYING BOTH PL AND N IMPROVED PLANT MACRONUTRIENT CONCENTRATION, WHILE ONLY APPLYING PC INCREASED N CONCENTRATION. THESE RESULTS COULD BE CONSIDERED AS THE BEST RECOMMENDED PRACTICES FOR USING PL AND PC.

CRONOBACTER IS A BACTERIAL GENUS THAT INCLUDES SEVEN SPECIES, AND THE SPECIES CRONOBACTER SAKAZAKII IS MOST RELATED TO MENINGITIS AND SEPTICEMIA IN INFANTS ASSOCIATED WITH POWDERED INFANT FORMULA (PIF). THE OBJECTIVES OF THIS STUDY WERE TO EVALUATE THE PRESENCE OF C. SAKAZAKII AND TO DETERMINE THE MICROBIOLOGICAL QUALITY OF PIF FOR INFANT CONSUMPTION. TO DO THIS, A TOTAL OF 128 PIF SAMPLES WERE ANALYZED IN FOUR BRANDS AND COUNTRIES (CHILE, MEXICO, HOLLAND, AND BRAZIL), CONSIDERING THREE TYPES OF PIF: PREMATURE (PIF1), INFANT (PIF2), AND FOLLOW-UP (PIF3). AEROBIC PLATE COUNTS (APC) AND ENTEROBACTERIACEAE (ENT) WERE ASSESSED IN ACCORDANCE WITH CHILEAN OFFICIAL STANDARDS. THE OUTER MEMBRANE PROTEIN A (OMPA) GENE WAS AMPLIFIED TO DETECT CRONOBACTER SPP. AND THE FUSA GENE WAS AMPLIFIED TO IDENTIFY C. SAKAZAKII BY USING THE PUBMLST WEB SITE AND BLAST (NCBI). THE ANTIBIOTIC RESISTANCE PROFILE WAS PERFORMED ACCORDING TO THE CLINICAL AND LABORATORY STANDARDS INSTITUTE STANDARDS. THE PATHOGEN WAS QUANTIFIED BY THE MOST PROBABLE NUMBER (MPN). THE RESULTS SHOWED THAT APC MEDIAN VALUES FOR PIF1, PIF2, AND PIF3 WERE 3.2, 4.9, AND 4.8 LOG CFU G-1, RESPECTIVELY. THE APC WERE HIGHER IN PIF2 (P < 0.01) FROM HOLLAND (P < 0.01) IN THE COMMERCIAL BRAND 4 (P < 0.01). THE ENT MEDIAN VALUES IN PIF1, PIF2, AND PIF3 WERE 1.8, 1.5, AND 1.7 LOG CFU G-1, RESPECTIVELY. FIVE STRAINS OF C. SAKAZAKII AND ONE STRAIN OF CRONOBACTER MALONATICUS WERE IDENTIFIED AS HAVING VALUES BETWEEN 0.023 AND 2.3 MPN/G. ALL STRAINS (100%) HARBORED THE OMPA, PLASMINOGEN ACTIVATOR (CPA), AND HEMOLYSIN (HLY) VIRULENCE GENES. TO CONCLUDE, C. SAKAZAKII WAS FOUND IN FOUR PIF SAMPLES FROM FOUR CHILEAN PRODUCTS AND ONE FROM MEXICO, WHICH IS DISTRIBUTED THROUGHOUT AMERICA. C. SAKAZAKII STRAINS EXHIBIT VIRULENCE FACTORS AND RESISTANCE TO AMPICILLIN, THUS POSING A RISK WHEN PIFS ARE CONSUMED BY INFANTS.

PROTEIN ADSORPTION IS INFLUENCED BY MANY FACTORS SUCH AS TEMPERATURE, PH, PROTEIN SIZE AND STRUCTURE, OR SURFACE ENERGY AND ROUGHNESS, AMONG OTHERS. SELF-ASSEMBLED MONOLAYERS (SAMS) AND THE LANGMUIR-BLODGETT (LB) TECHNIQUE ARE TWO OF THE TECHNIQUES MORE USED TO PRODUCES ULTRATHIN FILMS OF PROTEINS ON SURFACES. IN THIS WORK, WE ESTABLISHED PROTOCOLS FOR THE PREPARATION OF NANOCOATINGS OF BOVINE SERUM ALBUMIN (BSA) PROTEIN ON GLASS SURFACE USING SAMS AND LB. FURTHERMORE, WE DETERMINED HOW SMALL CHANGES IN TEMPERATURE AND PH CAN AFFECT THE COVERING WHEN SAMS ARE USED. USING A COMBINATION OF DIFFERENT ANALYSES, SUCH AS RELATIVE ROUGHNESS, DYNAMIC CONTACT ANGLES, AND ATOMIC FORCE MICROSCOPY (AFM), IT WAS POSSIBLE TO ESTABLISH CONDITIONS TO OBTAIN A UNIFORM NANOCOATING USING SAMS. THE RESULTS OF THE ANALYSIS OF THE NANOCOATING PERFORMED USING THE LB TECHNIQUE WERE VERY SIMILAR TO THOSE OBTAINED USING SAMS. THE DERJAGUIN?LANDAU?VERWEY?OVERBEEK (DLVO) THEORY IN CONJUNCTION WITH THE AFM IMAGES SHOWED THAT ELECTROSTATIC INTERACTIONS ARE VERY IMPORTANT IN THE SELF-ASSEMBLY PROCESS, BUT A PROCESS DOMINATED SOLELY BY ATTRACTION IS NOT SUFFICIENT TO ACHIEVE A GOOD SAM NANOCOATING, SINCE IT DOES NOT ALLOW PROPER ORIENTATION AND PACKAGING OF BSA MOLECULES ON THE GLASS SURFACE.

THIS ARTICLE DESCRIBES THE PRODUCTION OF NANOPARTICLES OF CHILEAN NATURAL ZEOLITE, USING THREE SIZE REDUCTION METHODS: BALL MILL, MICROGRINDING, AND MICROFLUIDIZATION. MORPHOLOGICAL CHARACTERIZATION OF SAMPLES INDICATED AN AVERAGE DIAMETER OF 37.2 ± 15.8 NM OF THE ZEOLITE PARTICLES. THE SIZE REDUCTION AND CHEMICAL TREATMENTS DID NOT AFFECT THE MORPHOLOGY OR INTEGRITY OF THE ZEOLITE. AN INCREASE OF THE ZEOLITE SAMPLES SI/AL RATIO WAS OBSERVED AFTER THE ACID TREATMENT AND WAS CONFIRMED BY SEM-EDX ANALYSIS. MOREOVER, THE EFFECTIVENESS OF THE COPPER SALT ION EXCHANGE (CU2+) TO THE ZEOLITE NANOPARTICLES WAS ANALYZED BY SEM-EDX. XRD ANALYSIS INDICATED THAT CLINOPTILOLITE AND MORDENITE ARE THE MAIN PHASES OF CHILEAN NATURAL ZEOLITE, AND THE CRYSTALLINE STRUCTURE WAS NOT AFFECTED BY THE MODIFICATION PROCESSES. THE FTIR CHARACTERIZATION SHOWED THE PRESENCE OF CHEMICAL BONDS OF COPPER WITH THE ZEOLITE NANOPARTICLE FRAMEWORK. THE ION-EXCHANGED ZEOLITE NANOPARTICLES WERE EVALUATED FOR ANTIBACTERIAL BEHAVIOR BY THE DISC DIFFUSION METHOD. ADDITIONALLY, THE MINIMUM INHIBITORY CONCENTRATION AND MINIMUM BACTERICIDAL CONCENTRATION WERE OBTAINED. MICROBIOLOGICAL ASSAYS WITH COPPER-EXCHANGED NANOZEOLITES SHOWED AN ANTIMICROBIAL ACTIVITY WITH A BACTERICIDAL EFFECT AGAINST ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS, WHICH ARE THE PRIMARY PATHOGENS OF FOOD AND ARE ALSO RESISTANT TO MULTIPLE DRUGS. IN THIS STUDY, A NEW APPLICATION FOR NATURAL NANOZEOLITES IS DEMONSTRATED, AS THE INCORPORATED COPPER IONS (CU2+) IN NANOZEOLITES REGISTERED A PRODUCTIVE ANTIBACTERIAL ACTIVITY.

READY-TO-EAT (RTE) ARTISANAL FOODS ARE VERY POPULAR, BUT THEY CAN BE CONTAMINATED BY LISTERIA MONOCYTOGENES. THE AIM WAS TO DETERMINE THE PRESENCE OF L. MONOCYTOGENES IN ARTISANAL RTE FOODS AND EVALUATE ITS FOOD SAFETY RISK. WE ANALYZED 400 RTE ARTISANAL FOOD SAMPLES REQUIRING MINIMAL (FRESH PRODUCTS MANUFACTURED BY A PRIMARY PRODUCER) OR MODERATE PROCESSING (CULINARY PRODUCTS FOR SALE FROM THE HOME, RESTAURANTS SUCH AS SMALL CAFÉS, OR ON THE STREET). LISTERIA MONOCYTOGENES WAS ISOLATED ACCORDING TO THE ISO 11290-1:2017 STANDARD, DETECTED WITH VIDAS EQUIPMENT, AND IDENTIFIED BY REAL-TIME POLYMERASE CHAIN REACTION (PCR). A SMALL SUBSET (N = 8) OF THE STRAINS WERE FURTHER CHARACTERIZED FOR EVALUATION. THE ANTIBIOTIC RESISTANCE PROFILE WAS DETERMINED BY THE CLSI METHODOLOGY, AND THE VIRULENCE GENES HLYA, PRFA, AND INLA WERE DETECTED BY PCR. GENOTYPING WAS PERFORMED BY PULSED-FIELD GEL ELECTROPHORESIS (PFGE). LISTERIA MONOCYTOGENES WAS DETECTED IN 7.5% OF RTE ARTISANAL FOODS. ON THE BASIS OF FOOD TYPE, POSITIVITY IN MINIMALLY PROCESSED ARTISANAL FOODS WAS 11.6%, SIGNIFICANTLY DIFFERENT FROM MODERATELY PROCESSED FOODS WITH 6.2% POSITIVITY (P > 0.05). ALL THE L. MONOCYTOGENES STRAINS (N = 8) AMPLIFIED THE THREE VIRULENCE GENES, WHILE SIX STRAINS EXHIBITED PREMATURE STOP CODONS (PMSC) IN THE INLA GENE; TWO STRAINS WERE RESISTANT TO AMPICILLIN AND ONE STRAIN WAS RESISTANT TO SULFAMETHOXAZOLE-TRIMETHOPRIM. SEVEN STRAINS WERE 1/2A SEROTYPE AND ONE WAS A 4B STRAIN. THE SAMPLED RTE ARTISANAL FOODS DID NOT MEET THE MICROBIOLOGICAL CRITERIA FOR L. MONOCYTOGENES ACCORDING TO THE CHILEAN FOOD SANITARY REGULATIONS. THE PRESENCE OF VIRULENCE FACTORS AND ANTIBIOTIC-RESISTANT STRAINS MAKE THE CONSUMPTION OF RTE ARTISANAL FOODS A RISK FOR THE HYPERSENSITIVE POPULATION THAT CONSUMES THEM.

TO DETECT THE PRESENCE OF BLOOD SERUM ANTIBODIES AGAINST NEWCASTLE DISEASE (ND) AND AVIAN INFLUENZA (AI) VIRUSES, TO UNDERSTAND THE CONTRIBUTION OF WILD BIRDS IN TRANSMISSION OF THESE VIRUSES IN CHILE. MATERIALS AND METHODS. SIXTY-THREE BIRDS BELONGING TO ORDERS FALCONIFORMES AND STRIGIFORMES WERE ANALYZED FROM BIRD REHABILITATION CENTERS IN CENTRAL AND SOUTH-CENTRAL CHILE. HEMAGGLUTINATION INHIBITION (HIA) WAS USED TO DETECT ANTIBODIES AGAINST THE ND VIRUS AND FURTHER AI VIRUS TYPING WAS DONE BY AGAR GEL IMMUNE-DIFFUSION (AGID) AND ELISA. RESULTS. 14 BIRDS WE FOUND (22.2%) WITH SERUM ANTIBODIES AGAINST ND VIRUS; HOWEVER, THERE WERE NO BLOOD SERUM ANTIBODIES TO AI VIRUS. CONCLUSIONS. BIRDS OF PREY FROM RESCUE CENTERS HAVE BEEN DETECTED POSITIVE FOR SERUM ANTIBODIES AGAINST ND VIRUS. BIRDS OF PREY COULD HAVE BECOME POSITIVE VIA DIRECT CONSUMPTION OF CHICKENS VACCINATED AGAINST ND OR FROM CHICKENS INDIRECTLY EXPOSED TO THE VACCINE THROUGH DIFFERENT ADMINISTRATIVE PROCEDURES (AEROSOLS, WATER TROUGHS) OR AFTER THE ADMISSION OF MIGRATORY BIRDS TO RESCUE CENTERS, WHICH COULD FACILITATE THE SPREAD OF ND FROM THEIR COUNTRIES OF ORIGIN, AND SHOULD BE INVESTIGATED.