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M I Caffer

Publications and source records attributed to M I Caffer.

17 recordsLinked to original sources

Salmonella enteritidis in Argentina.

A significant increase in the number of isolations of Salmonella enteritidis has been observed in Argentina since 1986. Outbreaks of foodborne diseases in humans were associated with the consumption of raw or undercooked hens' eggs. Between 1986 and the first 6 months of 1993 there were 150 outbreaks reported, affecting more than 6000 persons. A total of 71.3% of these outbreaks were confirmed by stool cultures, and 47.3% by bacteriological study of the food implicated in the outbreak. A permanent surveillance of salmonellosis is imperative, taking into account the persistence of Salmonella enteritidis isolations in sporadic cases and in new outbreaks.

Animals↗

[Diagnosis of entero-invasive Escherichia coli associated with diarrhea].

Sixteen Escherichia coli strains isolated from diarrhea patients, characterized as enteroinvasive (EIEC) by the keratoconjunctivitis test (Sereny test), and 15 non-EIEC strains, were studied. The aim of this study was to establish a possible correlation between the Sereny test and several other tests as enzyme-linked immunosorbent assay (ELISA) and biochemical markers, which are more easily accessible to general practice laboratories. Strains were assayed for the virulence marker antigen (the outer membrane proteins) by direct ELISA, biochemical tests, antimicrobial susceptibility profile and serotyping. Mean optical density (OD) values in the ELISA were 2.018 +/- 0.336 for EIEC strains, and 0.569 +/- 0.283 for non-EIEC strains. Difference between the OD values of the two groups was found to be significant at p < 0.01 by the one-tailed Student's test. One (6.2%) of the 16 Sereny test-positive strains was negative by ELISA. Considered as a group, the EIEC strains are rather heterogeneous in their biochemical characteristics. Lysine decarboxylase test appeared as the most relevant assay, since all EIEC strains were negative for this enzyme, whereas 66.7% of non-EIEC strains were positive. Other helpful tests performed for strain characterization were: gas production from glucose and from glycerol, sucrose and salicin fermentation, and esculin hydrolysis (p < 0.01). However, strains behaviour was variable with these tests. Differences between both groups of strains with regard to mucate utilization and dulcitol fermentation was significative only to a 5% level. Antibiotic sensitivity patterns showed differences between EIEC and non-EIEC strains: 37.5% of the former vs 80% of the latter, were resistant to at least four of the antibiotics tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Serotypes of Salmonella isolated from the Luján River, Argentina].

In this work, the serotypes of Salmonella genus polluting the waters of Lujan River, situated in the north east of the province of Buenos Aires, Argentina, were studied. A total of 690 samples of water were collected and analysed from February 1988 through December 1989, at three different sites. They were obtained according to the Moore technique and then preenriched in buffered peptone water and enriched in Rappaport-Vassiliadis Soya peptone broth was carried out. The isolations were realised in brilliant green-desoxycholate agar and bismuth sulphite agar and the presumptive colonies to be Salmonella were tested by the standard biochemical identification. Salmonella spp. was isolated in 434 samples (62.9%). The predominant serotype was S. Anatum, followed in a decreasing order by S. Montevideo, S. Newport and S. Bredeney. A large amount of serotypes that are isolated with very low frequency and very rarely in other hidric courses in the country were: S. Westhampton, S. Poona and S. Saintpaul were found.

Argentina↗

[Yersinia enterocolitica strains of bovine origin isolated in San Luis, Argentina: virulence, enterotoxigenicity, and antibiotic sensitivity].

Eleven Yersinia enterocolitica strains isolated from bovine tongues and classified as B1 0:5 Lis Xz (8), B2 0:9 Lis X3 (2), nontypable (1), were examined for the following virulence-associated characteristics: autoagglutination, calcium dependency, Sereny test, congo red binding and presence of 40-48 MDa plasmids. Heat-stable enterotoxin production was also determined. Antibiotic susceptibility was assayed according to the modified Bauer-Kirby's method. Two Y. enterocolitica B1 0:5 Lis Xz strains were positive for autoagglutination, calcium dependency and congo red binding; both exhibited nearly 40 MDa plasmids and one of them was enterotoxigenic. The other strains did not carry virulence-associated plasmids, 5 were congo red positive and 4 produced enterotoxin. Therefore, two B1 0:5 Lis Xz strains would be potentially virulent. All strains were susceptible to piperacillin, mezlocillin, cefuroxime, cefotaxime, amikacin, kanamycin, sisomicin, phosphomycin , chloramphenicol, trimethoprim-sulfamethoxazole and pipemidic acid. Ampicillin and sulfisoxazole proved to be less efficient.

Animals↗

[Bacteria of the genus Yersinia in chickens for human consumption and in balanced bird food].

Yersinia was investigated in 50 skin samples of chicken carcasses from retail shops and 65 samples of balanced food for domestic fowl. Enrichments were performed in saline phosphate buffer 0.067 M, pH 7.6 and post-enriched in 0.5% KOH. Subcultures were performed in Salmonella-Shigella agar and MacConkey agar. Isolates were identified through biochemical, serological and lysotyping methods. The following biovar (B), serovar (O) and phagovar (Lis) were isolated from chickens: Y. enterocolitica (five strains) B:1:O:6,47;Lis Xz; B:1;O:6:Lis Xz; B:1:O:5,Lis Xz; Y.intermedia (two strains) B:1;O:52;Lis Xz; B:1;O:52,53,54;Lis Xz (NRA, nitrate reductase type A); Y. frederiksenii (two strains) O:10,K1,25,35,38,46:Lis Xz; (citrate): O:10,K1,25,35,38,46:Lis Xz (ONPG-: citrate +); Y. kristensenii (one strain) does not agglutinate; Lis Xo. Yersinia were not isolated from balanced food for domestic fowl. Virulence tests (calcium dependency and autoagglutination at 37 degrees C) were negative in all instances. It is concluded from this study that Yersinia isolated from chickens are without pathogenic importance.

Animal Feed↗

[Significance of Salmonella enteritidis in outbreaks of diseases transmitted by foods in Argentina, 1986-1988].

This paper reports on the outbreaks of food-borne-diseases due to Salmonella Enteritidis which occurred in Argentina between 1986 and 1988. In 39 registered episodes 210 strains were isolated from human feces (28 outbreaks) and 59 from food (23 outbreaks). More than 2,500 people in different provinces were affected, the chief characteristics of the clinical picture being the gravity of the symptoms (high temperature, vomiting, diarrhea and severe dehydration). The main source of infection was related to raw eggs, eaten in the form of home-made mayonnaise. It is considered necessary to carry out an effective control of poultry products, as well as a permanent surveillance of salmonellosis.

Animals↗

[Comparative study of 4 methods for isolating Salmonella from surface waters].

The study presented here is the first stage of a project designed to determine the presence of Salmonella serotypes in Lujan river waters, which flow beside the urban area of the homonymous city, in the province of Buenos Aires. It consisted in a comparative study of four methods for Salmonellae detection in 200 samples: Tetrathionate-brilliant green; mannitol-selenite; Rappaport 25 and modified Rappaport-Vassiliadis broth, each of them with and without pre-enrichment in buffered peptone water. The submerged gauze technique was applied to the sampling in three different spots of the river: at the town center, two km water above, and two down-stream from the city. Best results were obtained when modified Rappaport-Vassiliadis enrichment broth and brilliant green agar with 0.25% of sodium deoxycholate were used, after pre-enrichment of the samples in buffered peptone water. Salmonella were isolated from 46% of the samples studied, and 16 serotypes were identified: S. Typhimurium, S. Enteritidis, S. Infantis, S. Mbandaka, S. Israel and S. Subspecies IV 18 z36: z38:-, among them.

Bacteriological Techniques↗

[The first isolations of Salmonella Zaiman in humans].

This paper describes the first three Salmonella Zaiman cases in children of more than one year old with acute infectious diarrhoea of less than seven days evolution, in the Pediatric Department of R. Madariaga Hospital in Posadas, Misiones. This sero-variety was isolated by hemoculture in an 11 year old girl with urinary infection and sepsis. This Salmonella is a new sero-variety isolated from Zaiman river which flows through suburbs of Posadas.

Adolescent↗

[Salmonella taxonomy].

Throughout the years, Salmonella nomenclature has suffered continual revisions, due to the confusion created by the different criteria adopted by the several groups of researchers. At the present time, it is recognized that the genus Salmonella is a single species, composed by seven taxa, with the level of subspecies (subsp.), which can be divided into serovars, described in the Kauffmann-White scheme. The name of four the species type Salmonella is Salmonella enteral sp. nov. nom. rev. The serovar of the taxon I is designated, for instance, Salmonella subsp. I ser. Typhimurium. For the other taxa, less frequent in human or animal pathology, the name of the subsp., followed by the antigenic formula (e.g. Salmonella subsp. IV 50: b-) is used. This criterion has been validated by the International Committee of Systematic Bacteriology and the names of the serovars are included in the Approved Lists of Bacterial Names.

Salmonella↗

[Evaluation of the hygienico-sanitary quality of fresh noodles].

Total mesophyllic aerobes (MT), total coliforms (CT), fecal coliforms (CF), Escherichia coli (EC), molds and yeasts (HyL) and Salmonella were studied in 50 samples of fresh noodles (32 to 35% water) prepared with dried or with liquid egg. Values obtained were: (in parenthesis number of positive samples) MT, 10(4) to 10(6) CFU/g (48%). HyL, 10(2) to 10(4) CFU/g (76%). CT, 4 to 100/g (32%) and 460/g (2%). CF, 3 to 10/g (14%) and 21/g (6%). For EC only two samples were positive with 4 and 9/g respectively. The same serovar of Salmonella (S. oranienburg) was detected in 88% of the samples.

Enterobacteriaceae↗

[New worldwide Salmonella serovar isolated in a case of diarrhea].

The isolation of a new serovar of Salmonella from fecal material belonging to a child with acute diarrhea in the ville of Orán, province of Salta, is reported. Because of its biochemical characteristics it was classified within the sub-species IV, taxon 5, according to the present nomenclature for this genus, being its antigenic structure 50:b:-(S IV 50:b:-).

Argentina↗

[Presentation of salmonellosis in the Tandil district, Argentina].

From January 1990 to July 1992 a prospective study on the salmonellosis form of presentation, reservoirs and transmission in Tandil was carried out. Forty strains of Salmonella enterica were isolated with the following distribution: 28 humans (17 children and 11 adults), 6 in foods (1 in raw milk, 3 in well water, 1 in home made mayonnaise and 1 in chicken salad) and 6 in animals (1 in cow, 2 in chicken and 2 in calves). Salmonella Enteritidis was the most frequent isolate. Disease was evident only in a few susceptible hosts and the epidemiological chain could not be determined in all the cases.

Adult↗

[Salmonella Freetown: 1st isolation in Argentina].

In this paper we report the first case of Salmonella Freetown in Argentina. It was isolated from a stool sample of a child of 1 month and 7 days, assisted as outpatient in the Hospital de Niños Dr. Ricardo Gutiérrez of the city of Santa Fe. On the basis of the biochemical characteristics and antigenic formulae, this new serovar belongs to the species Salmonella enterica subspecies enterica.

Argentina↗

[Cases of gastroenteritis associated to Vibrio cholerae no 01 in Oran, Salta].

Forty-one sporadic cases of non-O group 1 Vibrio cholerae gastroenteritis were detected in Orán, Salta, between February 1992 and February 1995. The frequency of isolation was 0.9% of the diarrhea cases. Out of 41 patients, 21 (51.2%) were older than 15 years and 25 (60.9%) were male. All the patients had diarrhea, 24 (58.5%) had watery stools and 6 (14.6%) cholera-like diarrhea; 10 (24.4%) presented vomiting and 12 (29%) mild dehydration. Six malnourished children who suffered from diarrhea with moderate dehydration for more than a week, were hospitalized. V. cholerae non O1 and Shigella flexneri were isolated from one patient, during the first outbreak and V. cholerae non O1 and Salmonella IV 50:b:- were recovered simultaneously from another patient during the fourth outbreak. A 72 year old woman died during the second cholera outbreak. The symptoms were: watery diarrhea, vomiting, fever and mild dehydration. A strain of V. cholerae O5, that did not produce cholera toxin, heat-stable enterotoxin, Kanagawa-like hemolysin or verocitotoxin was detected. It was positive for El Tor hemolysin and D-mannose and L-fucose resistant cells-associated hemagglutinins. Among the 41 isolates studied, all were oxidase and indole positive, fermented glucose, saccharose and mannitol. They were all motile, produced lysine and ornithine decarboxylases but not arginine dihydrolase or hydrogen sulfide. They were sensitive to O129 vibriostatic compound. None of them belonged to O1 or O139 serogroup and they did not produce cholera troxin. Among the V. cholerae non O1 strains isolated, 9.5% were resistant to ampicillin and 4.9% to trimethoprim-sulfamethoxazole. Active surveillance had shown that V. cholerae non-O1 is not an important agent of diarrhea in Orán, Salta.

Adolescent↗

[Agglutination of hen egg-yolk immunoglobulins (IgY) against Salmonella enterica, serovar enteritidis].

Two groups of 6 laying hens were used to produce IgY. In the vaccinated group (V), hens were injected by intramuscular route with two doses of a Salmonella enterica serovar Enteritidis bacterin at 20-day interval. In the control group (T) hens remained unvaccinated. Four IgY extractions were performed on the egg production of both groups. The first two extractions were carried out using the yolks obtained from the eggs produced during the 4th and 5th post-vaccination week (extracts 1V and 1T) and the other two using the ones from the 6th, 7th and 8th week (2V and 2T). Starting from the extracts 1V and 1T other products were obtained by freezing-thawing (1V-A and 1T-A) and simple (1V-B and 1T-B) or double (1V-C and 1T-C) flow capillary dialysis concentration. All these products were compared using an ELISA test specific for the detection of chicken antibodies against flagellar antigens of S. Enteritidis. In this test, V extracts were positive whereas T extracts were negative. The extract 1V was more positive than the extract 2V. The extract 1V-C was the most positive and was therefore selected to be used as an antiserum in the agglutination tests. This extract contained 1.9 g/dl of total proteins, 0.028 g/dl of triglycerides and 0.012 g/dl of cholesterol and showed an electrophoretic pattern characteristic of IgY. The 1T-C extract was used as a negative control in the agglutination tests. Slide somatic and tube flagellar agglutination tests were simultaneously carried out using both IgY extracts and a standard rabbit anti-Salmonella (IgG) sera. Overall 367 strains from the Enterobacteriaceae family were tested together with two other strains belonging to the Vibrionaceae family. The 1V-C extract specifically agglutinated S. Enteritidis strains in the same way as the rabbit sera. This extract also agglutinated other Salmonella strains antigenically related to S. Enteritidis. Salmonella which did not share somatic or flagellar antigens with S. Enteritidis, other different species of the Enterobacteriaceae family and the two strains of the Vibrionaceae family were all negative. None of the strains tested was agglutinated by the 1T-C extract. This paper show that it is possible to use specific IgY to identify S. enterica serovars. The more extended use of IgY for diagnostic purposes may be a convenient way to complement the current use of mammal polyclonal antibodies.

Agglutination Tests↗