Evolution of drug resistance in Salmonella panama isolates in Chile

Abstract

In a search for Salmonella isolates in the environment in Chile in 1975, drug-susceptible strains of Salmonella panama were recovered for the first time from river water and vegetables in the vicinity of Santiago. Two to 3 years later, antibiotic-resistant S. panama began to appear in a variety of sources (meat, animals, vegetables, etc.), giving rise to a human epidemic that involved the entire nation. Of 139 clinical isolates studied, 7 were drug susceptible, 11 were resistant only to nitrofurans, and 3 were streptomycin, spectinomycin, and nitrofuran resistant; none of these 21 isolates harbored plasmid DNA. Most isolates (n = 107) were resistant to nitrofurans (chromosomal) and to streptomycin, spectinomycin, sulfonamides, tetracycline, and mercuric and tellurite salts; this multidrug resistance was encoded on a 218-kb plasmid classified in a number of strains as being in the IncHI2 group. From 1982 to 1993, 11 isolates acquired an additional self-transferable plasmid coding for resistance to any one of ampicillin (61 kb), ampicillin and trimethoprim (65 kb), ampicillin, trimethoprim, streptomycin, and sulfonamides (71 kb), ampicillin, gentamicin, kanamycin, and tetracycline (120 kb), or a nontransferable plasmid of approximately 6 kb encoding resistance to ampicillin or kanamycin. With the exception of ampicillin or ampicillin and trimethoprim resistance, S. panama isolates from foodstuffs, mainly pork meat products, and animals had resistance patterns that were the same as those found in clinical specimens. Remarkably, strains from goats and goat cheese and from shellfish isolated in particular rural regions were either drug susceptible or resistant only to streptomycin-spectinomycin encoded on a mobile genetic element and to nitrofurans. The report describes the arrival of a susceptible S. panama strain, its spread all over the country, and the evolution of progressively complex resistance patterns.

Salmonella enterica serovars Panama and Arechavaleta: Risk Factors for Invasive Non-Typhoidal Salmonella Disease in Guadeloupe, French West Indies

“…4,6 Panama was also the major serovar in humans in Colombia and Chile. 9,10 This high prevalence is in contrast to that in other regions of the world, including mainland France (0.5% in 2011), 11 highlighting the specific epidemiology of these regions. In industrialized countries, NTS is transmitted predominantly through commercially produced food contaminated with animal feces.…”

Occurrence of antibiotic resistance and class 1, 2 and 3 integrons in Escherichia coli isolated from a densely populated estuary (Seine, France)

“…DNA was extracted from each of the 279 E. coli isolates (January 2006) using a Magna Pure LC apparatus (Roche, Germany) according to the manufacturer's recommendations, quantified by OD assay at 260 nm and adjusted to 100 μg mL −1 . Escherichia coli K‐12 DH1 containing plasmids PSU 2056 (Arakawa et al , 1995), PVC 2554 (Cordano & Virgilio, 1996) or PSMB 731 (Martinez & De la Cruz, 1990), which respectively carry class 1, 2 and 3 integrons, were used as positive controls. Plasmid DNA was extracted from control isolates using the QIAprep Spin Miniprep kit (Qiagen SA, France), also according to the manufacturer's recommendations, quantified by OD assay and analysed by 1% agarose gel electrophoresis in TAE 0.5 × buffer (45 min × 100 V).…”

Propagation of TEM- and PSE-Type β-Lactamases among Amoxicillin-Resistant Salmonella spp. Isolated in France

“…␤-Lactam antibiotics are widely used in the treatment of salmonellosis. Recently, alarming reports have pointed out the rapid development of resistance to these agents, involving Salmonella serovars such as Enteritidis (28,44), Typhimurium (28,41,43), Panama (6), and Typhi (13) in several countries. Clinical strains of Salmonella spp.…”