First case of diarrhea due to Aliarcobacter butzleri (formerly Arcobacter butzleri) in Ecuador.

The first case of acute watery diarrhea disease due to Aliarcobacter butzleri (formerly Arcobacter butzleri) in Ecuador is reported. An infant presented with moderate protein-calorie malnutrition, dehydration and anemia. A curved Gram-negative organism was isolated from stools, having been preliminarily identified by phenotypic characteristics. Definitive identification was achieved by multiplex PCR. Aliarcobacter butzleri was the only pathogenic microorganism isolated. No other entero-pathogens, enterovirus or parasites were found. Our findings strongly suggest that in this specific case, A. butzleri was the etiological agent. Further investigations are needed to develop standardized diagnostic protocols and to establish the prevalence and significance of Aliarcobacter infections in humans.

Occurrence and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli isolated from domestic animals from Southern Ecuador / Ocorrência e comportamento antimicrobiano de espécies termotolerantes de Campylobacter isoladas de animais domésticos no sul do Equador

ABSTRACT: Occurrence and antimicrobial resistance profiles of Campylobacter jejuni and C. coli strains isolated from fecal samples of dogs, pigs, cows and hens in southern Ecuador were studied. Of the 250 samples studied, 84 (33.6%) were Campylobacter positive, with C. jejuni being more frequent (78.6%) than C. coli (21.4%), with the exception of porcine samples, from which C. coli was the only species isolated. Multidrug resistance was reported in 10 Campylobacter strains (11.9%), four C. jejuni and six C. coli, and was always associated with nalidixic acid and ciprofloxacin resistance. All of the amoxicillin-resistant strains were susceptible to amoxicillin-clavulanic acid and were therefore beta-lactamase producers. However, one strain of C. jejuni remained resistant with additional resistance to gentamycin. This is an uncommon resistance pattern in Campylobacter and could reflect different resistance mechanisms.

RESUMO: A ocorrência e resistência antimicrobiana de cepas de Campylobacter jejuni e C. coli isoladas de amostras fecais obtidas de cães, suínos, vacas e galinhas no sul do Equador foram determinadas. Das 250 amostras estudadas, 84 (33.6%) foram Campylobacter positivas, sendo C. jejuni mais frequente (78.6%) que C. coli (21.4%) com a exceção das amostras de suínos, das quais só fora isolada a espécie C. coli. Multirresistência foi encontrada em 10 cepas (11,9%), quatro C. jejuni e 6 C. coli, sempre associada à resistência ao ácido nalidíxico e à ciprofloxacina. Todas as cepas resistentes à ampicilina foram susceptíveis para amoxicilina-ácido clavulánico demonstrando que foram produtoras de beta-lactamase. Porém, uma cepa de C. jejuni permaneceu sendo resistente, apresentando, também, resistência à gentamicina. Este é um padrão de multirresistência incomum em Campylobacter e pode refletir diferentes mecanismos de resistência.

Occurrence and antimicrobial susceptibility of thermophilic Campylobacter species isolated from healthy children attending municipal care centers in Southern Ecuador.

The prevalence and antimicrobial susceptibility of Campylobacter jejuni and C. coli strains in healthy, well-nourished children of middle socioeconomic level from Southern Ecuador were determined. Among the 127 children studied, 17 (13.4%) harbored Campylobacter sp. corresponding to C. jejuni (7.1%) and C. coli (6.3%) with a higher concentration of C. jejuni among boys (8.6%) and C. coli (8.8%) among girls. C. jejuni showed high resistance to nalidixic acid and ciprofloxacin (77.8%), but susceptibility to all other antimicrobials tested. C. coli strains showed resistance to more antibiotics than C. jejuni strains including resistance to nalidixic acid (75%), ciprofloxacin (75%), erythromycin (12.5%) and ampicillin (28.6), but susceptible to gentamicin and amoxicillin/clavulanic acid.

In-vitro activity of several antimicrobial agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates expressing aminoglycoside-modifying enzymes: potency of plazomicin alone and in combination with other agents.

This study investigated the in-vitro activity of clinically relevant aminoglycosides and new antimicrobial agents-plazomicin, ceftobiprole and dalbavancin-against 55 methicillin-resistant Staphylococcus aureus (MRSA) isolates producing aminoglycoside-modifying enzymes (AMEs). The checkerboard method was used to assess synergism between plazomicin and four antibiotics (fosfomycin, ceftobiprole, cefoxitin and meropenem), and time-kill assays were performed for the most active combinations. Among the aminoglycosides tested, plazomicin was the most active agent against MRSA, with >90% of isolates being inhibited at a minimum inhibitory concentration (MIC) of ≤1 mg/L. MIC50 and MIC90 values for ceftobiprole and dalbavancin were 2 and 4 mg/L, and 0.125 and 0.125 mg/L, respectively. The most prevalent AME gene was aac(6')Ie-aph(2″)Ia (87.3%), followed by ant(4')Ia (52.7%) and aph(3')IIIa (52.7%). Plazomicin activity was not affected by the type or number of enzymes detected. In checkerboard and time-kill assays, indifference was the most common result achieved for the antibiotic combinations. Notably, no antagonism was observed with any combination tested. Overall, plazomicin in combination with meropenem had the highest synergistic effect, demonstrating synergy against seven isolates in the checkerboard assay and three isolates in time-kill curves. In conclusion, plazomicin showed potent activity against aminoglycoside-resistant MRSA isolates, regardless of the number and type of AMEs present. These findings indicate the potential utility of plazomicin in combination with meropenem for the treatment of MRSA infections.