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R Brosch

Publications and source records attributed to R Brosch.

At least 37 records · Page 2Linked to original sources
PubMed1995

Investigations related to the epidemic strain involved in the French listeriosis outbreak in 1992.

Two hundred seventy-nine cases of human listeriosis (92 pregnancy-related cases and 187 non-pregnancy-related cases) caused by a serovar 4b and phagovar 2389:2425:3274:2671:47:108:340 strain were identified in France between March and December 1992. Epidemiological investigations included a case-control study (not described here) and microbiological analyses of foods. Results of the case-control study and characterization of food isolates identified pork tongue in jelly, a ready-to-eat meat product, as the major vehicle of this outbreak, and to a lesser extent, delicatessen products contaminated secondarily during handling in food stores. As far as serotyping, phage typing, DNA macrorestriction pattern analysis (obtained by pulsed-field gel electrophoresis [PFGE]), and ribotyping are concerned, this epidemic strain is phenotypically and genomically closely related to strains responsible for major outbreaks of listeriosis previously observed in Europe and North America. The epidemic strain sensu stricto as defined by PFGE (2/1/3) displayed the same serovar, phagovar, ribovar, and ApaI and NotI PFGE patterns as the epidemic strains from outbreaks in Switzerland, California, and Denmark, but it consistently showed differences in the SmaI PFGE profile. This information greatly contributed to the identification of the major food vehicle (pork tongue in jelly) and further allowed exclusion of other foods (cheese) as possible sources of this major listeriosis epidemic.

Disease Outbreaks↗
PubMed1995

Use of pulsed-field gel electrophoresis to link sporadic cases of invasive listeriosis with recalled chocolate milk.

Pulsed-field gel electrophoresis established the linkage between recalled chocolate milk and a multistate invasive listeriosis outbreak during a four-product recall period. Listeria monocytogenes isolates from four hospitalized patients and an environmental dairy sample displayed AscI restriction endonuclease digestion profiles identical to that of the chocolate milk isolate.

Aged↗
PubMed1994

Pulsed-field fingerprinting of listeriae: identification of genomic divisions for Listeria monocytogenes and their correlation with serovar.

Clamped homogeneous electric field (CHEF) electrophoresis was optimized for genomic analyses of Listeria monocytogenes. Various human, animal, food, and environmental isolates, as well as strains representing other Listeria species, were separately digested with rarely cutting endonucleases. Of 176 L. monocytogenes strains analyzed, the enzymes AscI and ApaI established 63 and 72 unique restriction endonuclease digestion profiles (REDP), respectively. The 22 non-L. monocytogenes strains exhibited 18 AscI and 19 ApaI unique REDP. Statistical analyses of REDP information using the Dice coincidence index and principal component analysis revealed two distinct genomic divisions of L. monocytogenes that also correlated with the flagellar (H) antigen type: division I contained serovar 1/2a, 1/2c, 3a, and 3c stains and division II contained serovar 1/2b, 3b, 4b, 4d, and 4e strains. Division I isolates digested with ApaI were further grouped into cluster IA (serovar 1/2c and 3c) and cluster IB (serovar 1/2a and 3a) strains. Likewise, division II isolates digested with ApaI were further grouped into cluster IIA (serovar 1/2b and 3b) and cluster IIB (serovar 4b, 4d, and 4e) strains. These data indicate that genotypic data generated by CHEF can be directly related to phenotypic data generated by serotyping for establishing the overall relatedness of isolates. Moreover, these data further substantiate that CHEF analysis is a reproducible and highly discriminating method for characterizing L. monocytogenes strains at the molecular level.

Animals↗
PubMed1993

Characterization of Listeria strains isolated from soft cheese.

Three soft cheeses were exposed to quantitative analysis for listeria and found to contain a large number of listeria. Thirty-five of the listeria strains isolated from the three cheeses were characterized by use of biochemical tests, serotyping, phagetyping and DNA restriction enzyme analysis. Seven isolates were identified as Listeria innocua and 28 as Listeria monocytogenes. Two to four different clones of L. monocytogenes could be identified from each cheese. In contrast, only one clone could be detected among the L. innocua isolates. From an epidemiological point of view the findings of different clones of L. monocytogenes in the same cheese emphasize the need for typing several listeria isolates from one and the same food sample. It is concluded that the best overview of the population of the listeria strains is obtained after direct plating of the sample followed by enumeration, isolation and extensive typing.

Bacteriophage Typing↗
PubMed1993

Isolation and characterization of Listeria monocytogenes-specific nucleotide sequences.

Subtracter probe hybridization was used to screen a partial genomic library of a clinical isolate of Listeria monocytogenes. Three clones that hybridized with genomic DNA from 174 strains of L. monocytogenes but not with genomic DNA from 32 strains representing other Listeria spp. were recovered. These data establish the utility of subtracter probe hybridization for recovering L. monocytogenes-specific sequences.

Base Sequence↗
PubMed1993

Pulsed-field gel electrophoresis applied for comparing Listeria monocytogenes strains involved in outbreaks.

Recent food-borne outbreaks of human listeriosis as well as numerous sporadic cases have been mainly caused by Listeria monocytogenes serovar 4b strains. Thus, it was of interest to find out whether a certain clone or a certain few clones were responsible for these cases and especially for outbreaks. We used pulsed-field gel electrophoresis of large chromosomal DNA restriction fragments generated by ApaI, SmaI, or NotI to analyse 75 L. monocytogenes strains isolated during six major and eight smaller recent listeriosis outbreaks. These strains could be divided into 20 different genomic varieties. Thirteen of 14 strains isolated during major epidemics in Switzerland (1983-1987), the United States (California, 1985) and Denmark (1985-1987) demonstrated indistinguishable DNA restriction patterns. In contrast, strains responsible for the outbreaks in Canada (Nova Scotia, 1981), the United States (Massachusetts, 1983), France (Anjou, 1975-1976), New Zealand (1969), and Austria (1986) and some smaller outbreaks in France (1987, 1988, 1989) were each characterized by particular combinations of DNA restriction patterns. Seventy-seven percent of the tested strains could be classified into the previously described ApaI group A (Brosch et al. 1991), demonstrating a very close genomic relatedness. Because 49% of the epidemic strains selected for this study belonged to phagovar 2389/2425/3274/2671/47/108/340 or 2389/47/108/340, fifty-six additional strains of these phagovars, isolated from various origins, were also typed to determine whether differences in DNA restriction profiles between epidemic and randomly selected strains of the same phagovars could be pointed out. Variations in DNA patterns appeared more frequently within randomly selected strains than within epidemic strains.

Bacterial Typing Techniques↗
PubMed1992

[10 years foodborne listeriosis--an evaluation].

Foodborne listeriosis outbreaks, which occurred in the past 10 years, have raised new questions in listeriosis epidemiology. The renewed interest in listeriosis and Listeria monocytogenes has resulted in various efforts, which enormously enriched the knowledge about his relatively rare, but because of the high mortality rate, important infectious disease as well as about its causative agent. New data concerning epidemiology and therapy of human listeriosis as well as new experience with Listeria monocytogenes regarding virulence, typing, isolation, identification, occurrence in food and environment, behaviour towards disinfectants etc. have changed the view of human listeriosis prevention. The new aspects are summarized in this review.

Adult↗
PubMed1991

Use of pulsed field gel electrophoresis to compare large DNA-restriction fragments of Listeria monocytogenes strains belonging to serogroups 1/2 and 3.

Thirty-five Listeria monocytogenes strains belonging to serogroups 1/2 and 3 and isolated from various origins were characterized by whole cellular DNA restriction patterns using low-frequency cleavage enzymes and pulsed field gel electrophoresis. Seventeen restriction profiles were detected with ApaI, 18 with SmaI and 15 with NotI, the combination of these patterns allowing one to define at least 24 distinct groups within the 35 strains. The significant genomic diversity pointed out by this method can be of value in the epidemiological fingerprinting of L. monocytogenes.

Animals↗
PubMed1991

Use of pulsed field electrophoresis of DNA restriction fragments for comparing Listeria monocytogenes strains isolated from human infections and food in Austria.

Twenty-five Listeria monocytogenes strains of human and food origin were studied, using low-frequency-cleavage restriction endonucleases and pulsed field gel electrophoresis. Sixteen different restriction patterns were obtained using ApaI and SmaI. The human isolates showed profiles different from those of the food isolates, thus strongly suggesting that the two human infections selected for this study did not originate from the contaminated foodstuffs examined at the same time. This method allowed it to clearly distinguish between strains apparently similar [i.e. belonging to the same serovar and same origin (cheese samples from the same dairy plant)].

Animals↗
PubMed1989

On the drinking water situation on the Cape Verde Islands (Island of Santiago).

On the Cape Verde Islands drinking water investigations were made. The drinking water was tested in chemical and bacteriological respects as well as on amebas and rotaviruses. The isolated germs were investigated on their reaction against several antibiotics and chemotherapeutics by means of the agar diffusion test. The changing of drinking water quality from water-supply-places to the households was investigated as well. According to the fact, that only 10.6% of 207 public water supplies investigated show drinking water quality after ONORM, and that nearly 30% and 80.2% of them contained E. coli and coliforme germs respectively, the urgency of extensive sanitations of water supplies on the Cape Verde Islands is evident.

Amoeba↗
PubMed1989

A survey of leptospirological studies carried out on the Cape Verde Islands.

The authors subjected 611 human sera, 1295 sera of domestic and 211 sera of wild living animals from two islands of the Cape Verde archipelago to serological tests for leptospirosis. Among the human sera 7.2% reacted positively. Antibodies to L. bratislava of the serogroup Australis were most frequent (59.1% of all positive sera). Antibodies to L. icterohaemorrhagiae were found in 1.3% of the sera tested, to L. sejroe in 1.1%, to L. canicola in 0.7%, to L. pyrogenes in 0.3% and to L. pomona, L. bulgarica and L. grippotyphosa in 0.2% each. The existence of natural foci of leptospiroses could not be proved since tests of 211 wild-living mammals were all negative. The investigation of domestic animal sera showed a positivity of 3.1% with goats being positive most frequently (85% of all positive sera), followed by donkeys with 3.3% and cattle with 2.0%. Sera of dogs, sheep and pigs were all negative. The results indicate that anthropurgic foci exist on the Cape Verde Islands.

Animals↗
PubMed1989

[Water studies of inhabitants of refuse disposal sites in Cairo. 1].

In two waste disposal sites in Cairo, drinking water samples from springs, drinking vessels and kitchens were investigated. Total germ count lay seldom below one thousand and ten million pro ml. Apart from various faecal germs, Aeromonas hydrophila was also found. The high occurrence of diarrhoeal diseases among the inhabitants of the waste disposal sites can be traced with certainty to the extremely bad drinking water quality.

Colony Count, Microbial↗
PubMed1988

Investigation of human stool samples from the Cape Verde Islands (district Santa Cruz/Santiago).

Based on the rate of occurrence of diseases associated with diarrhoea, stool samples were also investigated; parasitologically, using the MiFC-enrichment method for intestinal parasites; serologically, using ELISA for rotavirus and bacteriologically for Shigella and Salmonella on the Cape Verde Islands. 90% of the samples came from children aged between 6 and 14 years. Entamoeba histolytica, the causal agent of amoebic dysentery was demonstrated in 17.4%, Lamblia intestinalis in 28.7% and rotavirus in 14.5%.

Adolescent↗
PubMed1988

On the drinking water situation on the Cape Verde Islands (Islands of Santiago).

On the Cape Verde Islands drinking water investigations were made. The drinking water was tested in chemical and bacteriological respects as well as on amoebas and rotaviruses. The isolated germs were investigated on their reaction against several antibiotics and chemotherapeutics by means of the agar diffusion test. The changing of drinking water quality from water supply places to households was investigated as well. The results make evident the urgency of extensive sanitations of water supply places on the Cape Verde Islands.

Amoeba↗
PubMed1988

Serological investigations for antibodies against Treponema pallidum on the Cape Verde Islands (Santiago and Santo Antao)--2. report.

On the Cape Verde Islands, Santiago and Santo Antao 581 human blood samples were collected. The VDRL and TPHA tests were employed in the serological examinations of samples for antibodies against Treponema pallidum. Positive reactions were shown in 2 of the 191 sera from the Santiago Island and in 12 of the 390 sera from the Santo Antao Island in both the VDRL and the TPHA tests. Including the alone TPHA-positives of 5 and 8 sera respectively, results in a 3.7% of positive sera for Santiago and a 5.1% for Santo Antao. By not taking into account children under 13 years of age, the positivity rises to 4.2% and 7.6% respectively. Giving a total contamination rate of 6.3% for Treponema pallidum.

Adolescent↗