Les salmonelloses au centre hospitalier universitaire de Fann à Dakar: aspects bactériologiques

Examination of common swifts (Apus apus) for salmonella shedding in the area of Hannover, Lower Saxony, Germany

OBJECTIVE

The available literature indicates a high prevalence of the zoonotic pathogen Salmonella (S.) enterica serovar Infantis in the common swift (Apus apus). This long-distance migrant, which only consumes aerial plankton, can reach high population densities in places with suitable breeding sites. Dedicated competent private persons take part in the hand rearing of juvenile common swifts in wildlife rescue centres, which unavoidably results in close contact with these avian patients. For this reason, we examined common swifts for shedding of Salmonella spp.

MATERIAL AND METHODS

In the years 2014 and 2019, intestinal swabs or fresh faeces of common swifts (2014: n = 54; 2019: n = 62) were examined microbiologically (DIN EN ISO 6579; Annex D) in the area of Hannover, Lower Saxony, Germany.

RESULTS

Salmonella spp. could not be detected in any of the examined common swifts within the investigation period and the studied area in 2014 and 2019.

CONCLUSION AND CLINICAL RELEVANCE

The results illustrate that the common swift is unlikely to be a natural reservoir of Salmonella spp. For the transmission of salmonella by swifts the local conditions with the corresponding environmental impact seem to play a significant role, and the risk of transmission should be assessed according to the region to be examined.

Contribution of Avian Salmonella enterica Isolates to Human Salmonellosis Cases in Constantine (Algeria)

An epidemiological investigation was carried out on one hundred Salmonella isolates from broiler farms, slaughterhouses, and human patients in the Constantine region of Algeria, in order to explore the contribution of avian strains to human salmonellosis cases in this region over the same period of time. The isolates were characterized by phenotypic as well as genotypic methods. A large variety of antimicrobial resistance profiles was found among human isolates, while only seven profiles were found among avian isolates. Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR), Insertion Sequence 200-PCR (IS200-PCR), and Pulsed Field Gel Electrophoresis (PFGE) resulted in the allocation of the isolates to 16, 20, and 34 different profiles, respectively. The 3 genotyping methods led to complementary results by underlining the clonality of some serovars with the diffusion and persistence of a single clone in the Constantine area as well as stressing the polymorphism present in isolates belonging to other serovars, indicating the diversity of potential reservoirs of nontyphoidal Salmonella. Altogether, our results seem to indicate that nontyphoidal avian Salmonella may play an important role in human salmonellosis in the Constantine region.

Clonal differences between Non-Typhoidal Salmonella (NTS) recovered from children and animals living in close contact in the Gambia

Background

Non-Typhoidal Salmonella (NTS) is an important cause of invasive bacterial disease and associated with mortality in Africa. However, little is known about the environmental reservoirs and predominant modes of transmission. Our study aimed to study the role of domestic animals in the transmission of NTS to humans in rural area of The Gambia.

Methodology

Human NTS isolates were obtained through an active population-based case-control surveillance study designated to determine the aetiology and epidemiology of enteric infections covering 27,567 Gambian children less than five years of age in the surveillance area. Fourteen children infected with NTS were traced back to their family compounds and anal swabs collected from 210 domestic animals present in their households. Identified NTSs were serotyped and genotyped by multi-locus sequencing typing.

Principal Findings

NTS was identified from 21/210 animal sources in the households of the 14 infected children. Chickens carried NTS more frequently than sheep and goats; 66.6%, 28.6% and 4.8% respectively. The most common NTS serovars were S. Colindale in humans (21.42%) and S. Poona in animals (14.28%). MLST on the 35 NTS revealed four new alleles and 24 sequence types (ST) of which 18 (75%) STs were novel. There was no overlap in serovars or genotypes of NTS recovered from humans or animal sources in the same household.

Conclusion

Our results do not support the hypothesis that humans and animals in close contact in the same household carry genotypically similar Salmonella serovars. These findings form an important baseline for future studies of transmission of NTS in humans and animals in Africa.

Salmonellosis is a neglected tropical disease causing serious dysentery and septicaemia particularly in young infants, elderly and immunocompromised individuals such as HIV patients and associated with substantial mortality in developing countries. Salmonellosis also constitutes a major public health problem as it is considered the most widespread bacterial zoonosis of food origin throughout the world. Many epidemiological data exist from developed countries concerning transmission of Non-Typhoidal Salmonella (NTS) but few are available from developing countries. In addition few studies in sub-Saharan Africa have considered the interface between humans and their environment in relation to animals present in the household and food hygiene. This study describes the prevalence of NTS among fourteen Gambian children and 210 domestic animals living in close proximity (household) to the children in a rural setting in The Gambia. We found that the domestic animals living in the same household as patients carried different NTS serovar and genotypes; indicating that zoonotic transmission does not occur in our setting. This study provides baseline data for future studies of transmission of NTS in rural Africa.

Risk factors associated withSalmonella entericasubsp.entericacontamination of chicken carcases in Senegal

The objective of this study was to identify the risk factors for Salmonella spp. contamination of Senegalese chicken carcases during slaughtering. One hundred and twenty traditional slaughterhouses were studied from January 2000 to December 2002 in and around Dakar. A questionnaire was administered to the slaughterers and samples of breast skin were taken to assess the Salmonella spp. status of chicken carcases. Results showed that 43.3% of the chicken batches were contaminated with Salmonella spp., with Salmonella Hadar and Salmonella Brancaster as the two main serovars. Salmonella spp. contamination of the live birds before slaughtering was related to contamination of the carcases after slaughtering. Feed withdrawal before slaughtering and thorough cleaning and disinfection procedures decreased the risk of Salmonella contamination. One individual worker for each slaughtering stage was also associated with a decreased risk of Salmonella contamination. Using scalding water for plucking increased the risk of contamination. These results will help slaughterers to produce safer products for local consumers.

[Emergence of multidrug resistant Salmonella strains in Lome (Togo)]

OBJECTIVE

This study had for aim to compare antibiotic resistance of 332 Salmonella enterica strains identified in human samples in the course of infections, in Lome.

DESIGN

The strains were collected over two periods: 1998-2002 (N=168) and 2003-2004 (N=164). The antibiotic susceptibility test was performed by disk diffusion assay.

RESULTS

The main serotypes identified were 147 Salmonella Typhi (44.3%), 97 Salmonella Typhimurium (29.2%), and 74 Salmonella Enteritidis (22.3%). The proportions of strains resistant to chloramphenicol, cotrimoxazol, and amoxicillin (first line antibiotics) varied respectively from 33, 46, and 57% in 1998-2002 to 73, 79, and 82% in 2003-2004 (P<0.0001). The percentage of resistance to ciprofloxacin or ceftriaxone was inferior to 10%.

CONCLUSION

Fluoroquinolones and third generation cephalosporins have become the first line antibiotics for the treatment of Salmonella in Lome (Togo).

Epidemiological analysis of Salmonella enterica ssp. enterica serovars Hadar, Brancaster and Enteritidis from humans and broiler chickens in Senegal using pulsed-field gel electrophoresis and antibiotic susceptibility

AIMS

Salmonella Hadar, Salmonella Brancaster and Salmonella Enteritidis are the main Salmonella enterica ssp. enterica serovars isolated from poultry in Senegal. Our objective was to analyse the pulsed-field gel electrophoresis (PFGE) and antibioresistance patterns of strains belonging to these serovars and to assess the significance of broiler-chicken meat as a source of human infection.

METHODS AND RESULTS

A total of 142 Salmonella isolates were analysed: 79 were isolated from Senegalese patients with sporadic diarrhoea (11 S. Hadar, nine S. Brancaster and 59 S. Enteritidis) and 63 from poultry (30 S. Hadar, 17 S. Brancaster and 16 S. Enteritidis). The PFGE of XbaI- and SpeI-digested chromosomal DNA gave 20 distinct profiles for S. Hadar, nine for S. Brancaster and 22 for S. Enteritidis. Each serovar was characterized by a major pulsotype which was X3S1 in 42% of S. Hadar, X8S1 in 53.8% of S. Brancaster and X1S2 in 43% of S. Enteritidis isolates. Human and poultry isolates of Salmonella had common PFGE patterns. Antibiosensitivity tests showed multiresistance (more than two drugs) was encountered in 14.5% of S. Hadar and in 5% of S. Enteritidis isolates. Resistance to quinolones was considered to be of particular importance and 14.5% of S. Hadar isolates were found to be resistant to nalidixic acid. CONLCUSIONS: The sharing of similar PFGE profiles among isolates from humans and poultry provided indirect evidence of Salmonella transmission from contaminated broiler meat. But most of the Salmonella isolates remained drug sensitive.

SIGNIFICANCE AND IMPACT OF THE STUDY

Efforts are needed to eliminate Salmonella from poultry meat intended for human consumption. This study has also highlighted the importance of continuous surveillance to monitor antimicrobial resistance in bacteria associated with animals and humans.

Risk factors associated with Salmonella enterica subsp. enterica contamination of chicken carcases in Senegal

This study was to identify the risk factors for Salmonella spp. contamination of Senegalese chicken carcases during slaughtering. One hundred and twenty traditional slaughterhouses were studied from January 2000 to December 2002 in and around Dakar. A questionnaire was answered by the slaughterers, and samples of breast skin were taken to assess the Salmonella status of chicken carcases. Results showed that 43.3% of the batches were contaminated with Salmonella, indicating Salmonella Hadar and Salmonella Brancaster as the two main serovars. Salmonella contamination of the carcases after slaughtering was related to contamination of the live birds. Feed withdrawal before slaughtering and thorough cleaning and disinfection procedures decreased the risk of contamination. One individual worker for each slaughtering stage was also associated with a decreasing risk of contamination. Using scalding water for plucking the chicken carcases increased contamination risk. These results will help slaughters to produce safer products for local consumers.

[Current aspects of Salmonella bacteremia cases in the Ibrahima Diop Mar Infectious Diseases clinic, Fann National Hospital Center (Senegal)]

OBJECTIVE

The aim of this study was to describe epidemiological, clinical and bacteriological aspects of Salmonella bacteremia in the Fann university hospital infectious diseases clinic.

PATIENTS AND METHOD

This study was carried out on data recorded between January 1, 1996 and December 31, 2003. The strains were identified according to biochemical (API 20E, BioMérieux) and antigenic features. Their susceptibility to antibiotic drugs was tested by antibiogram. Research of strains secreting of an extended-spectrum betalactamase was performed.

RESULTS

Fifty five cases of Salmonella bacteremia were recorded as follows: S.Typhi bacteremia (32 cases), S. Paratyphi C bacteremia (4 cases), S. typhimurium bacteremia (9 cases), S. enteritidis bacteremia (32 cases) and S. spp bacteremia (8 cases). All the strains were susceptible to ciprofloxacin, ceftriaxone, aztreonam, amoxicillin+clavulanic acid and 90 % of them were susceptible to cotrimoxazole. Bacteremia occurred in 50 HIV infected patients (49%). Salmonella other than Typhi bacteremia were more often present in patients with HIV (81% vs 36% in patients without HIV infection) (P = 0.00001). The lethality rate was 42%. This rate was higher in patients with HIV (56 vs 23% in patients without infection) (P = 0.002).

CONCLUSION

The lethality rate of Salmonella bacteremia is high, especially in AIDS patients. Therefore, priority must be given to prevention and chemoprophylaxis with cotrimoxazole should be a good way to reduce the incidence of bacteremia in AIDS patients.

Risk factors for Salmonella enterica subsp. enterica infection in senegalese broiler-chicken flocks

Our objective was to assess the association of managerial practices, general hygiene and Salmonella infection in Senegalese broiler flocks. Seventy broilers farms were studied from January 2000 to December 2001 around Dakar. A questionnaire was submitted to the farmers and samples of fresh broiler droppings were taken. A 28.6% of the flocks were infected by Salmonella (mainly Hadar and Brancaster serovars). Salmonella infection of the previous flock (OR = 6.82) and of day-old chicks (OR = 3.73), frequent poultry farmers' visits (OR = 5.38) and keeping sick birds inside the farm (OR = 5.32) increased the risk of Salmonella infection. But, using antibiotics on day-old chicks (OR = 0.17) and a detergent for cleaning (OR = 0.16) decreased the risk.