[Shigelosis outbreak in the city of Lujan, Argentina]. / Brote de shigelosis en la ciudad de Luján, Argentina.

The aim of this study was to describe an outbreak of Shigella sonnei that occurred in the city of Lujan, Buenos Aires, Argentina, in July 2012. Five individuals were affected after eating a hand-made Viennese-style pastry at a family gathering. All of them presented with fever, joint pain, chills and non-bloody diarrhea containing mucus. Stool cultures were performed in all cases and the samples taken from the pastry ingredients were analyzed microbiologically. S.sonnei was isolated and identified in all the patients involved as well as in the almond cream filling. The isolates were analyzed for determining the antimicrobial susceptibility and genetic profiles by pulsed field gel electrophoresis (PFGE). The results showed the genetic relationship among the isolates, confirming that the cases occurred due to the patients' exposure to the same source of infection, i.e., the almond cream. Being the almond cream an industrially-manufactured ingredient, an initial contamination could have been unlikely; however contamination might have occurred as a result of manipulation in the bakery.

Brote de shigelosis en la ciudad de Luján, Argentina / Shigelosis outbreak in the city of Lujan, Argentina

El objetivo del estudio fue describir un brote por Shigella sonnei ocurrido en julio de 2012 en Luján, Buenos Aires, Argentina. Estuvieron afectadas 5 personas que asistieron a una reunión familiar, donde consumieron una rosca vienesa de elaboración artesanal adquirida en un comercio. Todos presentaron fiebre, dolores articulares, escalofríos y diarrea no sanguinolenta con mucus. Se realizaron coprocultivos en los afectados y análisis microbiológicos de los ingredientes. Se aisló y caracterizó S.sonnei de todos los pacientes y de la crema de almendras empleada en la preparación de la rosca vienesa. A los aislamientos se les determinó el perfil de sensibilidad a los antimicrobianos y el genético por electroforesis en campo pulsado. Los resultados demostraron la relación genética de los aislamientos, y esto confirmó la ocurrencia de los casos por exposición a una misma fuente de infección, la crema de almendras. Al ser un ingrediente industrial, de improbable contaminación inicial, la crema de almendras podría haber sufrido una contaminación durante la manipulación en la panadería

The aim of this study was to describe an outbreak of Shigella sonnei that occurred in the city of Lujan, Buenos Aires, Argentina, in July 2012. Five individuals were affected after eating a handmade Viennese-style pastry at a family gathering. All of them presented with fever, joint pain, chills and non-bloody diarrhea containing mucus. Stool cultures were performed in all cases and the samples taken from the pastry ingredients were analyzed microbiologically. S.sonnei was isolated and identified in all the patients involved as well as in the almond cream filling. The isolates were analyzed for determining the antimicrobial susceptibility and genetic profiles by pulsed field gel electrophoresis (PFGE). The results showed the genetic relationship among the isolates, confirming that the cases occurred due to the patients' exposure to the same source of infection, i.e., the almond cream. Being the almond cream an industrially-manufactured ingredient, an initial contamination could have been unlikely; however contamination might have occurred as a result of manipulation in the bakery

Laboratory-based prospective surveillance for community outbreaks of Shigella spp. in Argentina.

BACKGROUND: To implement effective control measures, timely outbreak detection is essential. Shigella is the most common cause of bacterial diarrhea in Argentina. Highly resistant clones of Shigella have emerged, and outbreaks have been recognized in closed settings and in whole communities. We hereby report our experience with an evolving, integrated, laboratory-based, near real-time surveillance system operating in six contiguous provinces of Argentina during April 2009 to March 2012. METHODOLOGY: To detect localized shigellosis outbreaks timely, we used the prospective space-time permutation scan statistic algorithm of SaTScan, embedded in WHONET software. Twenty three laboratories sent updated Shigella data on a weekly basis to the National Reference Laboratory. Cluster detection analysis was performed at several taxonomic levels: for all Shigella spp., for serotypes within species and for antimicrobial resistance phenotypes within species. Shigella isolates associated with statistically significant signals (clusters in time/space with recurrence interval ≥365 days) were subtyped by pulsed field gel electrophoresis (PFGE) using PulseNet protocols. PRINCIPAL FINDINGS: In three years of active surveillance, our system detected 32 statistically significant events, 26 of them identified before hospital staff was aware of any unexpected increase in the number of Shigella isolates. Twenty-six signals were investigated by PFGE, which confirmed a close relationship among the isolates for 22 events (84.6%). Seven events were investigated epidemiologically, which revealed links among the patients. Seventeen events were found at the resistance profile level. The system detected events of public health importance: infrequent resistance profiles, long-lasting and/or re-emergent clusters and events important for their duration or size, which were reported to local public health authorities. CONCLUSIONS/SIGNIFICANCE: The WHONET-SaTScan system may serve as a model for surveillance and can be applied to other pathogens, implemented by other networks, and scaled up to national and international levels for early detection and control of outbreaks.

Isolation of Salmonella typhimurium from dead blue and gold macaws (Ara ararauna).

Two blue and gold macaw (Ara ararauna) chicks died of fatal salmonellosis in Buenos Aires Province, Argentina. The birds were histopathologically and microbiologically examined. Salmonella enterica subspecies enterica serovar Typhimurium was isolated from the liver, spleen, heart, lung, kidney, and intestine of both birds. All strains were susceptible to ampicillin, cephalothin, cefotaxime, enrofloxacin, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole. The XbaI-PFGE profile of the Salmonella Typhimurium isolated from the two animals, which shared the same cage, was identical and showed a unique pattern compared with 301 isolates included in the PulseNet national database of Salmonella pulsed-field gel electrophoresis patterns. This is the first report that describes fatal cases of salmonellosis from blue and gold macaws.

Evolution of multiresistance in nontyphoid salmonella serovars from 1984 to 1998 in Argentina.

Molecular evolution of multiresistance in nontyphoid Salmonella spp. was investigated with 155 isolates obtained in Argentina from 1984 to 1998. In 74 isolates obtained from 1984 to 1988 resistance was associated with the presence of Tn3, Tn9, class I (In0) and II (Tn7) integrons, and the aac(3)-IIa gene. Extended-spectrum cephalosporin (ESC) resistance in Salmonella spp. emerged in 1989, and 81 isolates resistant to at least one ESC and one aminoglycoside were collected thereafter. Among these, two patterns of antimicrobial resistance mechanisms were found: from 1989 to 1992, resistance was related to the spreading of Tn1331 and bla(CTX-M-2), in addition to the persistence of In0 and Tn7. From 1993 to 1998, several integrons were added to the first pattern and three integron groups (IG), namely, IG1 (38% of the isolates), IG2 (51%), and IG3 (11%), were identified. At least two beta-lactamase genes were detected in 65% of the isolates (after 1989) by PCR analysis. Furthermore, five beta-lactamase genes, bla(CTX-M-(2)), bla(OXA-9), bla(OXA-2), bla(TEM-1), and bla(PER-2), were found in two isolates. The bla(CTX-M-2) gene was found in several complex sulI-type integrons with different rearrays within the variable region of class I integrons, suggesting evolution of these integrons in nontyphoid Salmonella. In conclusion, progressive acquisition and accumulation of plasmid-mediated resistance determinants occurred from 1984 to 1998 in nontyphoid Salmonella isolates of the most prevalent serovars from Argentina. It is suggested that antimicrobial resistance mechanisms in these bacteria may have been the consequence of plasmid exchange between Salmonella enterica serovar Typhimurium and Escherichia coli or Shigella flexneri and/or spreading of mobile elements from the nosocomial environment.

Drug Resistance of Enterobacteriaceae Isolated from Chicken Carcasses.

The antibiotic resistance profiles and transferable R factors of Salmonella and Escherichia coli isolates from 104 broiler carcasses taken from one processing plant were determined. Carcasses were sampled after immersion chilling. All samples were transported iced and immediately analyzed upon arrival to the laboratory. The resistance patterns of isolates to 12 antibiotics were determined (i.e., ampicillin, cephalothin, streptomycin, sulfisoxazole, trim-ethoprim-sulfamethoxazole, nalidixic acid, tetracycline, neomycin, chloramphenicol, gentamicin, colistin, and nitrofurantoin). Isolates resistant to one or more antibiotics were utilized as donors of resistance to completely antibiotic-sensitive strains, an E. coli K-12, F-, J5, azide-resistant strain and a Salmonella serovar Enteritidis. Transfer of the different R plasmids was confirmed by the determination of the resistance patterns of the transconjugants. Of the 93 Salmonella and 71 E. coli strains isolated from these samples, the largest numbers were resistant to tetracycline (52.7% and 49.3%), sulfisoxazole (45.2% and 42.3%), and streptomycin (37.6% and 39.4%). Large percentages of the Salmonella (33.3%) and the E. coli (30.0%) strains transferred all or part of their resistance to E. coli K-12 in mixed cultures. Great variation was observed between different strains in the frequency at which they transferred resistance. Resistance to tetracycline, sulfisoxazole, and streptomycin was found to be conferred by 31.7%, 29.8%, and 21.6% of the 19 R factors identified. No transfer of resistance to nalidixic acid, gentamicin, cephalothin, nitrofurantoin, and chloramphenicol was detected. When 30 antibiotic-resistant E. coli strains were cultured with a sensitive strain of Salmonella serovar Enteritidis,7 (23.3%) of the resistant strains were found capable of transferring R factors. Only 2 (6.7%) of the resistant strains could transfer R factors and unusual ß-galactosidase activity.

Investigación de bacterias del género Yersinia en pollos destinados al consumo y en alimento balanceado para aves / Bacteria of the genus Yersinia in chickens for human consumption and in balanced bird food

Se ha investigado la presencia de bacterias del género Yersinia en 50 muestras de pollo faenados destinados al consumo y en 65 muestras de alimento balanceado para aves. Se enriquecieron en solución de buffer de fosfatos 0,067 M pH 7,6 en NaCl 0,145 M (PBS) a 4 -C durante 21 días. El post-enriquecimiento se realizó con KOK al 0,5%. Los aislamientos se hicieron sobre agar Salmonella-Shigella (SS) y agar MacConkey (MC). Las colonias sospechosas se sembraron en triple azúcar hierro (TSI). Las colonias se purificaron a través de pruebas bioquímicas, serológicas y de fagotipia. De las muestras de pollo se aisló Y. enterocolítica en un 10% con las siguientes biovar (B), serovar (O) y fagovar (Lis): B:1,0:6,47, Lis Xz; B:1, 0:6, Lis Xz; y B:1,0:5, Lis Xz; Y. intermedia en un 40%, B:1,0:52,Lis Xz y B:1,0:52,53,54,Lis Xz (NRA, nitrato reductasa de tipo A); Y. frederiksenii en un 4%, 0:10, K1,25,35,38,46, Lis Xz (citrato +) y 0:10,K1,25,35,38,46,Lis Xz (ONPG -: citrato +); Y kristensenii en un 2%, no aglutinable, Lis Xo. Del alimento balanceado para aves no se aisló Yersinia spp. todas las cepas fueron negativas a las pruebas de dependencia del calcio para el crecimiento y autoaglutinación a 37 -C indicandola ausencia de plasmidios de virulencia. También fueron negativas a la prueba de Sereny. Cuatro cepas fueron enterotoxina positivas. De los resultados obtendios se concluye que las cepas de Yersinia aisladas a partir de pollos no significan un riesgo para la salud (AU)

Investigación de bacterias del género Yersinia en pollos destinados al consumo y en alimento balanceado para aves / Bacteria of the genus Yersinia in chickens for human consumption and in balanced bird food

Se ha investigado la presencia de bacterias del género Yersinia en 50 muestras de pollo faenados destinados al consumo y en 65 muestras de alimento balanceado para aves. Se enriquecieron en solución de buffer de fosfatos 0,067 M pH 7,6 en NaCl 0,145 M (PBS) a 4 -C durante 21 días. El post-enriquecimiento se realizó con KOK al 0,5%. Los aislamientos se hicieron sobre agar Salmonella-Shigella (SS) y agar MacConkey (MC). Las colonias sospechosas se sembraron en triple azúcar hierro (TSI). Las colonias se purificaron a través de pruebas bioquímicas, serológicas y de fagotipia. De las muestras de pollo se aisló Y. enterocolítica en un 10% con las siguientes biovar (B), serovar (O) y fagovar (Lis): B:1,0:6,47, Lis Xz; B:1, 0:6, Lis Xz; y B:1,0:5, Lis Xz; Y. intermedia en un 40%, B:1,0:52,Lis Xz y B:1,0:52,53,54,Lis Xz (NRA, nitrato reductasa de tipo A); Y. frederiksenii en un 4%, 0:10, K1,25,35,38,46, Lis Xz (citrato +) y 0:10,K1,25,35,38,46,Lis Xz (ONPG -: citrato +); Y kristensenii en un 2%, no aglutinable, Lis Xo. Del alimento balanceado para aves no se aisló Yersinia spp. todas las cepas fueron negativas a las pruebas de dependencia del calcio para el crecimiento y autoaglutinación a 37 -C indicandola ausencia de plasmidios de virulencia. También fueron negativas a la prueba de Sereny. Cuatro cepas fueron enterotoxina positivas. De los resultados obtendios se concluye que las cepas de Yersinia aisladas a partir de pollos no significan un riesgo para la salud

Primeros aislamientos de Salmonella Zaimam en humanos / 1st isolations of Salmonella Zaiman in humans

Se comunican los tres primeros casos de Salmonella Zaiman en niños mayores de un año, afectados de idarrea aguda infecciosa de menos de siete días de evolución, internados en el Servicio de Pediatría del Hospital R. Madariaga de la ciudad de Posadas, Misiones. Además, esta serovariedad se aisló por hemocultivo de una niña de 11 años con infección urinaria y sepsis. Esta Salmonella es una nueva serovariedad aislada del arroyo Zaiman que recorre zonas suburbanas de Posadas (AU)

Primeros aislamientos de Salmonella Zaimam en humanos / 1st isolations of Salmonella Zaiman in humans

Se comunican los tres primeros casos de Salmonella Zaiman en niños mayores de un año, afectados de idarrea aguda infecciosa de menos de siete días de evolución, internados en el Servicio de Pediatría del Hospital R. Madariaga de la ciudad de Posadas, Misiones. Además, esta serovariedad se aisló por hemocultivo de una niña de 11 años con infección urinaria y sepsis. Esta Salmonella es una nueva serovariedad aislada del arroyo Zaiman que recorre zonas suburbanas de Posadas

Determinación de la calidad higiénico-sanitaria de fideos frescos / Determination of the hygienic-sanitary quality in fresh noodles

Mesófilos aerobios totales (MT), coliformes totales (CT), coliformes fecales (CF), Escherichia coli (EC), hongos y levaduras (HyL) y Salmonella fueron estudiados en 50 muestras de fideos frescos (32 a 35% de agua) preparados con huevo deshidratado o con huevo líquido. Los valores obtenidos fueron: (entre paréntesis el porcentaje de muestras positivas) MT, 10**4 a 10**6 UFC/g (48%); H y L, 10**2 UFC/g (76%); CT, 4 a 100/g (32%) y 460/g (2%); CF, 3 a 10/g (14%) y 21/g (6%). Para EC sólo dos muestras fueron positivas con 4 y 9/g respectivamente. Una sola serovariedad de salmonella (S. oranienburg) fue detectada en el 88% de las muestras

Determinación de la calidad higiénico-sanitaria de fideos frescos / Determination of the hygienic-sanitary quality in fresh noodles

Mesófilos aerobios totales (MT), coliformes totales (CT), coliformes fecales (CF), Escherichia coli (EC), hongos y levaduras (HyL) y Salmonella fueron estudiados en 50 muestras de fideos frescos (32 a 35% de agua) preparados con huevo deshidratado o con huevo líquido. Los valores obtenidos fueron: (entre paréntesis el porcentaje de muestras positivas) MT, 10**4 a 10**6 UFC/g (48%); H y L, 10**2 UFC/g (76%); CT, 4 a 100/g (32%) y 460/g (2%); CF, 3 a 10/g (14%) y 21/g (6%). Para EC sólo dos muestras fueron positivas con 4 y 9/g respectivamente. Una sola serovariedad de salmonella (S. oranienburg) fue detectada en el 88% de las muestras (AU)