Multi-drug resistant non-typhi salmonellae in Kenya

Abstract

Two methods of plasmid characterization, restriction digest patterns and incompatibility grouping, were used to study self-transmissible multi-drug resistance among non-typhi salmonellae (NTS). Resistance to ampicillin and other commonly applied beta-lactams was evaluated by iso-electric focusing and disc inactivation. Of the NTS isolated from blood, 75% were Salmonella typhimurium but those included several different phage types. Over 47% of isolates were resistant to three or more of the readily available drugs including ampicillin, cefuroxime, chloramphenicol, co-trimoxazole, streptomycin and tetracycline. Self-transferable resistance plasmids (c. 100 kb) were essentially of incompatibility group incFIIA, but their restriction fragment patterns revealed a diversity in relatedness. More than half of parent strains and their transconjugants produced beta-lactamases which co-electrophoresed with TEM-1 and OXA-1. This study has observed a disturbingly high prevalence of transmissible multi-drug resistance among NTS which are an important cause of morbidity in HIV-1 seropositive individuals.

Infections in AIDS

“…In Kenya, 75% of the blood isolates from adults with AIDS were Typhimurium with smaller proportions of Enteritidis (9.5%), Newport (8.4%) and Choleraesuis (3.6%) [150] and a similar pattern was found in Malawi [152]. However, in a recent study from Spain, 65% of the NTS blood isolates were Enteritidis and only 27% were Typhimurium [159].…”

“…In a Kenyan study, a total of 138 NTS isolations were made from 1220 episodes of fever in adults admitted to the Kenyatta Hospital, Nairobi [150]. This represented 11.3% of all blood cultures and well over 50% of positive blood cultures.…”

“…This represented 11.3% of all blood cultures and well over 50% of positive blood cultures. A total of 224 (19.7%) of the 1220 patients with febrile episodes were HIV seropositive, but 95 (68.8%) of the 138 with NTS bacteraemia were HIV infected, demonstrating a strong association (p ,0.001) between being HIV seropositive and having NTS bacteraemia [150]. In Malawi NTS were found to be a major cause of bacteraemia and of mortality in adults and showed an overwhelming association with HIV infection [152].…”

Preventing opportunistic infections among human immunodeficiency virus-infected adults in African countries.

“…The prevalence of cotrimoxazole resistance among enterobacteriacae in Abidjan is relatively low; in an earlier study, the prevalence of cotrimoxazole resistance among nontyphoid salmonellae in 1995 was 14%. 48 This compares with 46% in Kenya in 1993-1994 49 and 83% in Malawi in 1998, 50 and 39% 51 and 90% 52 among Salmonella spp. in Ethiopia during 1995 and in 1994-1996, respectively.…”

Using next generation sequencing to tackle non-typhoidal Salmonella infections

“…Previous authors highlight risk factors including human immunodeficiency virus (HIV) infection, extreme youth, malnutrition and malaria [2]. The greatest contributor to disease burden over the past decade is undoubtedly the increase in HIV-NTS co-infection [3,4,5,6] associated with a very high mortality [7,8]. The first report of NTS in an acquired immune deficiency syndrome (AIDS) patient was from Haiti in 1983 [9] and five case reports from New York, United States of America (USA,) all with S. Typhimurium, were reported in 1985 [10].…”