Detection of Salmonella spp. with the BACTEC 9240 Automated Blood Culture System in 2008 - 2014 in Southern Iran (Shiraz): Biogrouping, MIC, and Antimicrobial Susceptibility Profiles of Isolates

Abstract

BackgroundHuman salmonellosis continues to be a major international problem, in terms of both morbidity and economic losses. The antibiotic resistance of Salmonella is an increasing public health emergency, since infections from resistant bacteria are more difficult and costly to treat.ObjectivesThe aims of the present study were to investigate the isolation of Salmonella spp. with the BACTEC automated system from blood samples during 2008 - 2014 in southern Iran (Shiraz). Detection of subspecies, biogrouping, and antimicrobial susceptibility testing by the disc diffusion and agar dilution methods were performed.Patients and MethodsA total of 19 Salmonella spp. were consecutively isolated using BACTEC from blood samples of patients between 2008 and 2014 in Shiraz, Iran. The isolates were identified as Salmonella, based on biochemical tests embedded in the API-20E system. In order to characterize the biogroups and subspecies, biochemical testing was performed. Susceptibility testing (disc diffusion and agar dilution) and extended-spectrum β-lactamase (ESBL) detection were performed according to the clinical and laboratory standards institute (CLSI) guidelines.ResultsOf the total 19 Salmonella spp. isolates recovered by the BACTEC automated system, all belonged to the Salmonella enterica subsp. houtenae. Five isolates (26.5%) were resistant to azithromycin. Six (31.5%) isolates with the disc diffusion method and five (26.3%) with the agar dilution method displayed resistance to nalidixic acid (minimum inhibitory concentration [MIC] > 32 μg/mL). All nalidixic acid-resistant isolates were also ciprofloxacin-sensitive. All isolates were ESBL-negative. Twenty-one percent of isolates were found to be resistant to chloramphenicol (MIC ≥ 32 μg/mL), and 16% were resistant to ampicillin (MIC ≥ 32 μg/mL).ConclusionsThe results indicate that multidrug-resistant (MDR) strains of Salmonella are increasing in number, and fewer antibiotics may be useful for treating S. enterica infections. Routine investigation and reporting of antibiotic MICs in patients presenting with Salmonella infections is suggested.

Detection of Non-Typhoidal Salmonella Gastroenteritis in a Tertiary Children’s Hospital in China

“…An alarming increase in the antibiotic resistance by NTS was reported elsewhere (11,12). In our study, 54.3% of our isolates were found to be resistant to nalidixic acid, which is lower than that reported from India (77%) (22), Southwest China (66.7%) (27), and higher than that reported from Congo (4.3%) (33), Iraq (45.5%) (23), Ethiopia (23.9%) (34), and Iran (31.5%) (17). Among the NTS isolated from stool samples, Nalidixic acid was predominant among our NTS, (64.8%) which was very much higher than that reported from Kenya (6%) (16).…”

“…The spread of antibiotic resistance makes it difficult to treat infants and children due to limited availability of therapeutic options, raising serious public health concerns (11,16,17). Antibiotic resistance especially due to extended-spectrum cephalosporins has been considered to be a major problem in various geographical regions including North/Western, Asia, Africa, US and Europe (18).…”

Molecular Detection of Diffusely Adherent Escherichia coli Strains Associated with Diarrhea in Shiraz, Iran

“…Our findings are similar to those of the studies from Iran, Peru, Vietnam, Brazil and Mexico (29)(30)(31)(32)(33)(34). It should be also noted that in many cases, antibiotic resistance is transmitted to humans, hospitalized patients and the hospital environment through other sources, including food plants, animals, fish, poultries, and other industries, in which antibiotics are used for different purposes and may lead to the emergence of resistant strains (35)(36)(37)(38). The isolation, identification and antimicrobial susceptibility of pathogens can be helpful in optimizing the use of antimicrobial agents.…”

Diabetic Foot Infections: Antibiotic Susceptibility Patterns and Determination of Antibiotic Cross-Resistance in Clinical Isolates of Enterococcus Species During 2012 - 2014 in Shiraz, Iran

“…It should also be noted that, in many cases, antimicrobial resistance is transmitted to the human population, hospitalized patients, and the hospital environment through other sources including animals, plant-based foods, fish, poultry, and other industries in which antibiotics are used for different purposes and may lead to emerging resistant strains of bacteria (22)(23)(24)(25). The multidrug resistant (MDR) status attributed to the majority of the Enterococci continues to be highly relevant, especially in chronic severe Enterococci infections such as DFIs, since antimicrobial resistance often results in treatment failure.…”