Antibiotic Resistance Profile of Salmonella Strains Isolated at the National Clinical Biology and Public Health Laboratory in Bangui, Central African Republic

In Africa, each year, there are estimated to be more than 91 million cases of salmonellosis and 137,000 cases of death. The problem of antibiotic resistance in Salmonella strains is a threat to public health. The objective of this study is to evaluate the antibiotic resistance profile of Salmonella strains isolated in biological products analyzed at the National Laboratory of Clinical Biology and Public Health (NLCBPH) in Bangui. This is, therefore, a cross-sectional study with a descriptive aim, running from January to December 2022. It focused on the strains of Salmonella isolated and identified in stools, urines, and blood samples. For each strain of Salmonella isolated, an antibiogram was carried out following the recommendations of the French Society of Microbiology (CASFM, 2022). A total of 93 strains of Salmonella have been recorded. The age group 0 - 9 years was 29% and that of >50 years was 11%. The median age of patients was 30 years with a minimum of 1 and a maximum of 78 years. The female gender was more represented at 52.69% than the male gender at 47.31%, i.e. a sex ratio of 0.89 (M/F). Salmonella strains were much more isolated in stools at 62% followed by urines at 29% and blood at 6%. Salmonella arizonae strains were more represented with 52%. Salmonella strains have a resistance rate to Tetracycline of 62.37% followed by Penicillins of 50%. The rate of multi-antibiotic resistance of the Salmonella strains isolated represented 48.38%. Salmonella spp. strains were multi-resistant at 58.69% followed by Salmonella arizonae strains at 47.91%. There is a significant association between the different families of antibiotics and Salmonella strains (p < 0.05). According to the results obtained, Penicillins, Phenicoles, and Cyclins had a high rate of resistance on Salmonella strains. No strain-producing Broad Spectrum Beta-lactamase has been isolated. Salmonella strains represent a zoonotic health danger, constitute a public health problem and remain a current subject. This germ is resistant to the antibiotics used. It is, therefore, essential to emphasize monitoring the resistance of these germs in the Central African Republic (CAR) to improve the health of the population.

Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

Evaluation of the Microbiological Quality of Poultry Imported into Togo and the Antibiotic Resistance of Salmonella spp. Isolated

In Togo, despite the government’s efforts, food requirements in terms of animal proteins are not covered by national production and are subject to huge imports of meat products. However, the hygienic quality of these imports is not guaranteed for the consumer. The aim of this study was to estimate the frequency of unhygienically unsatisfactory imported poultry and to determine the antibiotic resistance profile of Salmonella spp. strains. A total of 285 samples of imported poultry, including 55 chicken thighs, 10 chicken backbones, 25 chicken wings, 5 whole chickens, 30 sausages, 35 chicken forequarters, 95 chicken drumsticks and 30 guinea fowl wings, were analyzed using standard AFNOR routine methods. The following germs were tested: Total Aerobic Mesophilic Flora (TAMF), Anaerobic-Sulfite-Reducing (ASR), Escherichia coli, Staphylococcus aureus and Salmonella spp. Antibiotic susceptibility testing was carried out on Salmonella spp. strains isolated using the agar disk diffusion method (CA-SFM). Results showed 100% compliance for TAMF, coagulase-positive Staphylococci and Escherichia coli. On the other hand, 3.84% and 2.46% non-compliance were recorded for ASR and Salmonella respectively. Non-compliance with hygiene rules is generally thought to be the cause of meat contamination. Seven 7 strains of Salmonella were isolated, 5 of which were of the OMA serogroup, and the other two of the OMB and HMB groups. Antibiotic susceptibility tests revealed resistance to certain beta-lactam antibiotics and quinolones, in particular: cefalexin (28.57%), cefoxitin (14.28%), cefuroxime (28.57%), ceftazidime (28.57%), ceftriaxone (28.57%) and nalidixic acid (28.57%). This result may be explained by the uncontrolled use of B-lactam and quinolone antibiotics in poultry farming. As Salmonella spp. is a pathogenic enteric bacterium that causes food-borne illness in humans, resistance to third-generation cephalosporins remains a major public health problem.

Bovine salmonellosis in Northeast of Iran:Frequency,genetic fingerprinting and antimicrobial resistance patterns of Salmonella spp.

Objective:To evaluate serovar and antimicrobial resistance patterns of Salmonella spp isolated from healthy,diseased and necropsied cows and calves in this observational study.Methods:Nineteen isolates recovered from feces and tissues of salmonellosis-affected animals of two commercial farms in north-east of Iran.In second part of the study,the two farms were sampled 4 times with an interval of 2 month.The samples included calves'feces,adult cows'feces,feeds,water,milk filters,and milk fed to calves.Five Salmonella were isolated from 332fecal samples collected from calves and peri-parturient cows.No Salmonella was recovered from water,feed,milk filers and milk fed to calves.Results:Salmonella Typhimurium was the most frequently isolate among all sero-groups.S.Dublin was only accounted for 8%(two out of 24)of isolates.Isolated Salmonella strains were used for the ERIC PCR DNA fingerprinting assay.Our results grouped Salmonella isolates into 3 clusters,suggesting that specific genotypes were responsible for each sero-group of Salmonella.The results also revealed diversity among Salmonella isolates in cluster III(sero-group B).Eighteen out of 19 Salmonella spp.were resistant to oxytetracycline.Five isolates out of 19 showed more than one drug resistance.Multi-drug resistance was seen only among Salmonella Typhimurium isolates.Enrofloxacin was the most susceptible antibiotic against all isolates in this study.Conclusion:The emergence of multiple antibiotic-resistant strains of Salmonella Typhimurium should be of great concern to the public.No correlation between ERIC fingerprinting and resistance patterns of Salmonella isolates was found,which indicates resistance to antimicrobial agents was not related to specific genetic background.

Mathematical Analysis of Relationship Between Resistance to Fluoroquinolones and GyrA Mutation of Salmonella from Animal

By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.

Antimicrobial Resistance and Plasmid Profiles of <i>Salmonella enterica</i>Serovars from Different Sources in Lagos, Nigeria

Introduction: Salmonella enterica Serovars remains one of the leading pathogens that cause diarrhoea and bloodstream infections in developing countries. The emergence of multidrug resistant (MDR) Salmonella has become a serious problem globally. This study investigated the antibiotic resistance and plasmid profiles of Salmonella isolates from different sources. Methods: Seventy-three samples comprised of clinical (30), hand swab (15), food (10) and water (18) were analyzed bacteriologically. Salmonella isolates were identified and characterized by standard procedures. Isolates were subjected to antimicrobial susceptibility testing and were further screened for plasmid DNA by standard methods. Results: A total of 27 Salmonella isolates made up of 5 (18.5%) S. typhi, 6 (22.2%) S. enteritidis, 9 (33.3) S. typhimurium, 5 (18.5%) S. cholerasuis, and 1 (3.7%) each of S.arizonae and S. vichow were obtained in this study. All the isolates developed resistance to three or more antibiotics evaluated. Four distinct resistance profiles: TetAmpCol, TetAmpColCot, TetAmpColCip and TetAmpColCotCip were recorded with 63% of the isolates exhibiting resistance profile TetAmpColCot. Specifically 23 of 27 (85.2%) of the isolates harboured plasmid DNA comprised of 12 distinct plasmid profiles of different sizes ranging from 3.2 kb to 30.2kb. Salmonella isolates of the same species from different sources differed in plasmid profile. Plasmid profile was found to show good discriminatory capability compared to antibiotics resistance profile. Conclusion: This study revealed that both resistance antibiogram and plasmid profile are still viable epidemiological tools for tracing the source of Salmonella isolates. A need for prudent use of antibiotics is suggested.

Food Safety and Antimicrobial Resistance an Approach to the Genus <i>Salmonella</i>spp.

Foodborne Illnesses (FI) are considered an important problem in public health for their high levels of morbidity and, in some cases, of mortality in Mexico and around the world. Different agents that cause Foodborne Illnesses, in which biological agents such as the genus Salmonella spp., are included, have been often associated with outbreaks. A continued effort has been observed in the food industry, in collaboration with sanitary authorities on a global scale, through the creation and continued improvement of different procedures to prevent the contamination by Salmonella, in which the elaboration of laboratory methodologies for the detection and isolation of this pathogen in foods and, in such manner, prevents the outbreak of illnesses. However, along with the aforementioned, it has been reported that a few years ago, the appearance of an ever-increasing number of strains of Salmonella spp., in foods with multi-drug resistance to antibiotics which are used in the treatment of its illness, results in a major emphasis on the health issue related to Foodborne Illnesses and, in particular, to those generated by factors of medical dependence such as the increase in recuperation time, costs, and reduction in the number of alternative pharmaceutical treatments. This work presents a general overview of FI, in which illnesses generated by bacteria of the genus Salmonella spp., their detection in a microbiological laboratory, as well as the phenomenon of resistance to antibiotics by these bacteria, and the current and difficult issue reported through different investigations all around the world, of the rise in this phenomenon and its importance in public health, are discussed.

Molecular characterization of antimicrobial multi-drug resistance in non-typhoidal Salmonellae from chicken and clam in Mangalore, India

Salmonella enterica has been documented as one of the leading causes of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated food products. Thus, this research was aimed at studying the antimicrobial susceptibility pattern and detection of quinolone resistance in Salmonella spp isolated from food of animal origin. Thirty-six Salmonella isolates comprising 8 from poultry and 28 from seafood（clams） were identified, serotyped and characterized for their antimicrobial susceptibility against 10 different antibiotics. Plasmid DNA was isolated from all the isolates by alkaline lysis, quinolone resistant non-typhoidal S. Weltevreden were examined for mutation in the DNA gyrase coding gene. Among the 36 Salmonella isolates, 20 were S. weltevreden（8 from poultry and 12 from seafood） and 16 were S. Typhimurium（from seafood）. All the isolates showed multiple resistance to nalidixic acid, tetracycline, co-trimoxazole and nitrofurantoin, but, interestingly, the isolates were 100% susceptible to ampicillin, chloramphenicol and gentamicin. Resistant isolates from the study carried the genes responsible for resistance to respective antibiotics. The strain S130 isolated in the study showed single point mutation,Asp87Gly, at position 87 in quinolone resistance determining region. It revealed mutation in quinolone resistance determining region as a cause for quinolone resistance in non-typhoidal Salmonellae. The occurrence of genes accountable for plasmid mediated resistance to quinolones（viz., qnrA, qnrB and qnrS） in plasmid of non-typhoidal Salmonellae isolates provides evidence for plasmid mediated quinolone resistance.

Antibiotic susceptibility and molecular characterization of resistance genes among Escherichia coli and among Salmonella subsp. in chicken food chains

Objective: To investigate the occurrence of resistance genes among Escherichia coli(E. coli) and Salmonella subsp. isolated in chicken food chains in Phnom Penh, 2012–2013.Methods: Six hundred eighty two E. coli and 181 Salmonella Albany, Corvallis, and Kentucky strains were examined for susceptibilities to eight antimicrobials and following resistance genes were identified by PCR: blaTem, Str A, aad A, sul1, sul2, gyr A, Tet(A), and Tet(B).Results: E. coli presented high resistances to tetracycline, amoxicillin, and sulfamethoxazole(63.1%–76.1%). Salmonella Albany and Salmonella Kentucky traduced high resistance percentages to amoxicillin, tetracycline, sulfamethoxazole, and nalidixic acid(84.6%–100%). Among amoxicillin-resistant isolates, blaTemgenes were observed for 62% of E. coli isolates and 20% of 65 Salmonella Kentucky. The Str A gene was prevalent in 36% of 331 aminoglycoside-resistant E. coli and 90% of 40 aminoglycoside-resistant Salmonella Corvallis. The sul2 gene was predominant among sulfamethoxazole-resistant isolates, for 56% of 431 E. coli and 53% of 66 Salmonella Corvallis; the sul1 gene was observed in 54% of Salmonella Albany. The Tet(A) resistance gene was prevalent in E.coli(86%), Salmonella Corvallis(82%), Salmonella Kentucky(84%). High percentages of gyr A genes observed among nalidixic-acid resistant E. coli(91%), Salmonella Albany(92%), Salmonella Corvallis(75%) and Salmonella Kentucky(85%).Conclusions: Important occurrences of resistance gene were observed among E. coli and Salmonella in chicken food chains in Cambodia.

A cross sectional study on antibiotic resistance pattern of Salmonella typhi clinical isolates from Bangladesh

Objective:To investigate and compare the resistance and sensitivity of Salmonella typhi samples to commonly used antibiotics in three major divisions of Bangladesh and to evaluate the gradually developing resistance pattern.Methods:The antibiotic susceptibility of 70 clinical isolates collected from blood,sputum,urine and pus samples were identified by specific antisera and with standard biochemical tests.The patients were divided into 5 age groups.Susceptibility and resistance was also tested by KirbyBauer disc-diffusion method using 12 regularly used antibiotics.Results:Antibiotic susceptibility test demonstrated that 64.28%isolates of Salmonella typhi were multidrug resistant.Present study suggests that the clinical samples were mostly resistant against nalidixic acid with all age groups and in all three divisions with similar resistance pattern.Resistance is more common among adult people(30-40 years)and children(0-10 years).Salmonella typhi was mostly sensitive against gentamycin,chloramphenicol and ciprofloxacin.Conclusions:Although the population density of Dhaka region is markedly higher than Rajshahi and Chittagong regions,no significant difference in resistance pattern was found.The rate of multidrug resistance is a matter of concern.Physicians should reconsider before prescribing nalidixic acid and cefixime.Further molecular study is needed to reveal the genomic and proteomic basis of resistance.

Isolation and Identification of Different Sources of Salmonella and Comparisons on the Drug Resistance Spectrum Types

[ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar Salmonella chromogenic culture, Reveal Salmonella detection kit and molecular biology methods were used for isolation and identification of Salmonella from different animal feces samples. Antibacterialantimi- crobial susceptibility tests of 17 kinds of drugs such as enrofloxacin, apramycin and florfenicol were done on isolated strains with broth microdilution method, and test data was analysed with WHOnet 5.4 software. [ Results ] 699 feces samples from different animals were separated, and 53 strains of Salmonella were achieved with separation rate of 7.58%, among which those of yak, poultry, and pet sources were respectively 4.33%, 9.06% and 8.37%. [ Condusions] Separation rates and drug resistance spectrum types of different animal origin Salmonella varied greatly, among which separation rates and drug resistance spectrum types of yak source Salmonella were the lowest, there was little difference between separation rates of poultry and dog source Salmonella, however there were large differences on drug resistance spectrum types.

Antimicrobial Drug Resistance and Plasmid Profiles of <i>Salmonella</i>Isolates from Humans and Foods of Animal Origin in Uganda

Salmonella organisms are among the most common causes of human bacterial gastroenteritis worldwide, and food animals are important reservoirs of these bacteria. A further danger lies in the development of drug resistance in these organisms, primarily driven by non-prudent overuse of antiinfectives. The current study compared the plasmid profiles and drug susceptibility patterns of Salmonella isolates from man and foods of animal origin in Uganda. A total of 92 Salmonella isolates (58 from man and 34 from foods of animal origin) were analyzed. Identification was done by using biochemical tests;plasmid profiling by agarose gel electrophoresis while susceptibility testing to tetracycline, ampicillin, chloramphenicol, nalidixic acid, trimethoprim-sulphamethoxazole, ciprofloxacin, ceftriaxone and tetracycline were done by the Kirby Bauer Disc Diffusion method. Among the human isolates, 57/58 (98.3%, 95% CI, 91.8% - 99.9%) were susceptible to Ciprofloxacin compared to 32/34 (94.1%, 95% CI, 81.9% - 91%) of animal-derived isolates. On the other hand, 48/58 (82.7%, 95% CI, 71.4% - 91%) human-derived isolates were resistant to Trimethoprim sulfamethoxazole compared to 29/34(85.3%) of the animal-derived isolates. Fifty four percent (n = 50) of the all the isolates were resistant to at least three antibiotics whereas only 2.2% (n = 2) were susceptible to all the seven drugs tested. Most worrying, however, was the fact that only 45% percent of the isolates were sensitive to all the three drugs (chloramphenicol, nalidixic acid and ciprofloxacin) commonly used in the treatment of salmonellosis in this setting. The risk of ampicillin resistance was three times more likely to occur in animal-derived as compared to human-derived isolates (Odds Ratio = 2.705, 95% CI, 1.3 - 5.8) as was that to nalidixic acid (Odds Ratio = 2.895, 95% CI, 1.17 - 7.2). Plasmid profile analysis showed eight clusters comprising of 68.7% (46/67) of the isolates. In five of the eight clusters, there were both animal and human-derived isolates. Resistant strains of Salmonella are common in this setting and meat/meat products are the commonest source of infection. A majority of the isolates are multi-drug resistant, and there is evidence of cross-species transmission of plasmids, and possibly drug resistance, between animals and humans.

Antimicrobial Resistance Profile of Salmonella Isolates from Livestock

Food animals are important reservoirs of infectious pathogens. The use of antimicrobial drugs in food animals is a major source of selection of drug resistant pathogens. This study investigated a total of 1000 faecal samples of livestock and poultry between January 2012 and March 2013 to determine the prevalence rate of Salmonella species and their antimicrobial resistance profiles. Faecal samples of chicken, pig, cattle, goat and sheep (200 samples of each) were pre-enriched in Tetrathionate broth and Rappapport Vassiliadis R10 broth. The broth culture was subcultured on XLD agar and incubated. The isolates were identified by standard biochemical tests and confirmed by AP1 20E test kit. Antimicrobial susceptibility was performed by disk diffusion method. The result showed that the prevalence of Salmonella spp. in all the samples was 21.8%. Chicken faeces had the highest prevalence rate of 52.5% followed by pig faeces (40%), cattle (10%), goat (4.5%) and sheep (2%). The isolates have resistance profile ranging from 1 to 9 antimicrobial drugs. Tetracycline had the highest resistance (81%) of all the isolates followed by Streptomycin (68%). Gentamycin had the lowest resistance profile of 14%. We conclude that Salmonella species have high prevalence rate in chicken and pig, but less in cattle, goat and sheep, and that most of the isolates are resistant to most commonly used antibiotics. Effort is needed to adopt measures to control the spread of multidrug resistant pathogens to humans. Care must be taken in the use of antibiotics in farm animals to reduce the selection of multidrug resistant strains.

Prevalence and Antibiotic Resistance of <i>Salmonella</i>spp. in Turkey

The current study was conducted to investigate the prevalence of Salmonella spp. in turkey and to determine the antimicrobial resistance pattern of the isolated Salmonellae. Two hundred and fifty turkeys were randomly selected for cloacal soab samples preparation, and the samples were investigated for Salmonella isolation. Identification of the isolated Salmonella was performed using standard bacteriological and biochemical procedures. The prevalence of Salmonella in turkey was about 14.8%. Disc diffusion tests on Muller-Hinton agar were used to determine the sensitivity to antibacterial agents. Ten antibiotics were studied: lincospectin, colistin, cephalexin, ciprofloxacin, chloramphenicol, gentamycin, furazolidone, streptomycin, co-trimoxazole (trimethoprim-sulfamethoxazole) and tetracycline. The highest resistant was observed against cephalexin (89.2%), tetracycline (86.5%), colistin (83.8%), and furazolidone (73%). The Highest sensitivity was found to gentamycin (86.5%), ciprofloxacin (83.8%), chloramphenicol (51.4%) and streptomycin (40.6%). The results showed high prevalence of Salmonella spp. in turkey and high levels of antimicrobial resistance pattern of the isolated Salmonellae were observed.

Analysis of Trends in Resistance to Fluoroquinolones and Extended Spectrum Beta-Lactams among <i>Salmonella</i>Typhi Isolates Obtained from Patients at Four Outpatient Clinics in Nairobi County, Kenya

Typhoid fever caused by the bacterium Salmonella enterica serovar Typhi (S. Typhi) causes an estimated 25 million illnesses and approximately 200,000 deaths annually mostly in developing countries. Although the management of typhoid fever has been effectively through antibiotic treatment, S. Typhi is increasingly becoming resistant to the currently recommended drugs. This study utilized a quasi-experimental design focusing on archived samples to describe antimicrobial susceptibility patterns of S. Typhi and determine the genetic basis of resistance to the two most commonly used classes of antimicrobials. A total sample size of 287 isolates of S. Typhi isolates stored in -80°C freezer at the Centre for Microbiology Research was utilized. Isolates were subjected to anti-microbial susceptibility testing to commonly available antimicrobials using disk diffusion method, then analyzed for trends in resistance to fluoroquinolones and extended spectrum beta lactams. Among the 287 isolates 158 (55.5%) were found to be Multi Drug Resistant (MDR). This implied that these isolates were resistant to all first line classes of treatment such as ampicillin, chloramphenicol and sulfamethoxazole-trimethroprim. In addition to this, these isolates were also resistant to at least one of the currently recommended drugs of choice, either a β-lactam or a fluoroquinolone. This study observed resistances at 18.2% and 15.4% to fluoroquinolones and cephalosporins respectively. PCR results revealed presence of blaTEM, blaINT and blaCTX-M genes coding for resistance to β-lactams in 80% of the isolates that had combined resistance to β-lactams and fluoroquinolones. It is likely that recent heavy use of these classes of antimicrobials is driving resistances to these antimicrobials.

Molecular Detection of Mutations within the Quinolone Resistance-Determining Regions in Non Typhoidal Salmonella Isolates from Malaysia

Introduction: The efficacy of chemotherapy in bacteraemia caused by non-typhoidal Salmonella (NTS) is compromised by antibiotic resistance. Objective: This study was undertaken to describe the mechanism of resistance among clinical NTS isolates. Materials & Methodology: Thirty of NTS were isolated from blood (n = 19), stool (n = 10) and bronchioalveolar lavage (BAL;n = 1) respectively. These isolates were tested for susceptibility testing by disc diffusion method against ampicillin, gentamicin, tetracycline, co-trimoxazole, nalidixic acid, ciprofloxacin and ceftriaxone. Epsilometer tests (E-test) for nalidixic acid and ciprofloxacin were performed for nalidixic acid resistant isolates by disc diffusion method. DNA sequencing was carried out on six of the nalidixic acid resistant Salmonella Enteritidis isolates to identify mutations within quinolones resistance determining regions (QRDR) of gyrA, gyrB, parC and parE genes. Results: Resistance rates of NTS isolates from blood, stool, and BAL were respectively 37%, 20% and 0% for ampicillin, 79%, 40% and 0% for tetracycline, 32%, 40% and 0% for co-trimoxazole, 37%, 10% and 100% for nalidixic acid. Eight isolates were resistant to nalidixic acid and had exhibited reduced susceptibility towards ciprofloxacin by E-test. Mutation within QRDR was detected in gyrA gene (n = 6;Asp 47 → His [3], Asp 51 → Asn [1], Asp 73 → Gly [1], and Gly 48 → Asp [1]) and double mutation was detected in parE gene (n = 3;Gly 48 → Asp [3], Glu 82 → Ser [3]). Out of six isolates, three isolates were found to have both gyrA and parE gene mutations. Conclusions: There was no mutation observed in gyrB and parC gene. Mutation in gyrA gene was sufficient to induce decreased susceptibility to ciprofloxacin. Variation in amino acid sequences are novel, while detection of other gene mutation was uncommon.

Prevalence and antimicrobial resistance of non-typhoid Solmonella in military personnel,1988-2013

Objective:To describe the spanning 25 years data for the occurrence, magnitude, and trends regarding antimicrobial resistance of non-typhoidalSalmonella (NTS) isolated from non-immune travelers to Thailand participating in joint military operations.Methods:A total of 355 NTS isolates, obtained from 2052 fecal samples from US soldiers deployed for military maneuvers in Thailand during 1988-2013, were examined for NTS serogroup/serotypes and tested for antimicrobial susceptibility by disk diffusion to these 10 antibiotics:ampicillin, azithromycin (AZM), ciprofloxacin, colistin, gentamicin, kanamycin, nalidixic acid, streptomycin (STR), tetracycline (TET), and trimethoprim/sulfamethoxazole. Identified AZM-resistant NTS isolates were further evaluated for their minimal inhibitory concentration by the E-test method.Results:NTS infections accounted for 17.3％ (355/2052), including 11 serogroups and 50 different serotypes. The most prevalent serogroup wasSalmonella group C2-C3 (35.8％, 127/355) followed by groups B (21.1％, 75/355) and C1 (18.6％, 66/355). Identified serotypes includedSalmonellahadar (n=60),Salmonellarissen (n=45), andSalmonella blockley (n=34). Among the predominate serogroups, antimicrobial resistance was consistently high against TET (76.9％, 273/355) followed by STR (40.8％, 145/355). OneSalmonella senftenberg isolate demonstrated decreased ciprofloxacin susceptibility. Most isolates (94.6％) were resistant to one or more antimicrobials, and the most common multidrug resistance was TET-STR-nalidixic acid (11.5％, 41/355).Conclusions:The prevalence of NTS serotypes and the growing magnitude of antibiotic resistant bacteria isolated from deployed US military in Thailand are documented from 1988-2013. This study demonstrates the antibiotic resistance profiles, highlighting the effectiveness of AZM that is a first-line treatment for travelers to Southeast Asia. AZM-resistant NTS isolates are periodically observed over a 25-year period. Hence, the ongoing surveillance and prevalence efforts are required to monitor NTS resistant strains causing further treatment failure.

Severe infection with multidrug-resistant Salmonella choleraesuis in a young patient with primary sclerosing cholangitis

Massive global spread of multidrug-resistant(MDR) Salmonella spp. expressing extended-spectrum beta-lactamase(ESBL) and additional resistance to fluoroquinolones has often been attributed to high international mobility as well as excessive use of oral antibiotics in livestock farming. However, MDR Salmonella spp. have not been mentioned as a widespread pathogen in clinical settings so far. We demonstrate the case of a 25-year-old male with primary sclerosing cholangitis who tested positive for MDR Salmonella enterica serotype Choleraesuis expressing ESBL and fluoroquinolone resistance. The pathogen was supposedly acquired during a trip to Thailand, causing severe fever, cholangitis andpancreatitis. To our knowledge, this is the first report of Salmonella enterica serotype Choleraesuis in Europe expressing such a multidrug resistance pattern. ESBL resistance of Salmonella enterica spp. should be considered in patients with obstructive biliary tract pathology and travel history in endemic countries.

Prevalence and antimicrobial resistance of non-typhoid Solmonella in military personnel,1988-2013

Objective:To describe the spanning 25 years data for the occurrence,magnitude,and trends regarding antimicrobial resistance of non-typhoidal Salmonella(NTS)isolated from non-immune travelers to Thailand participating in joint military operations.Methods:A total of 355 NTS isolates,obtained from 2052 fecal samples from US soldiers deployed for military maneuvers in Thailand during 1988-2013,were examined for NTS serogroup/serotypes and tested for antimicrobial susceptibility by disk diffusion to these 10 antibiotics:ampicillin,azithromycin(AZM),ciprofloxacin,colistin,gentamicin,kanamycin,nalidixic acid,streptomycin(STR),tetracycline(TET),and trimethoprim/sulfamethoxazole.Identified AZM-resistant NTS isolates were further evaluated for their minimal inhibitory concentration by the E-test method.Results:NTS infections accounted for 17.3%(355/2052),including11 serogroups and 50 different serotypes.The most prevalent serogroup was Salmonella group C2-C3(35.8%,127/355)followed by groups B(21.1%,75/355)and C1(18.6%,66/355).Identified serotypes included Salmonella hadar(n=60),Salmonella rissen(n=45),and Salmonella blockley(n=34).Among the predominate serogroups,antimicrobial resistance was consistently high against TET(76.9%,273/355)followed by STR(40.8%,145/355).One Salmonella senftenberg isolate demonstrated decreased ciprofloxacin susceptibility.Most isolates(94.6%)were resistant to one or more antimicrobials,and the most common multidrug resistance was TET-STR-nalidixic acid(11.5%,41/355).Conclusions:The prevalence of NTS serotypes and the growing magnitude of antibiotic resistant bacteria isolated from deployed US military in Thailand are documented from 1988-2013.This study demonstrates the antibiotic resistance profiles,highlighting the effectiveness of AZM that is a first-line treatment for travelers to Southeast Asia.AZM-resistant NTS isolates are periodically observed over a 25-year period.Hence,the ongoing surveillance and prevalence efforts are required to monitor NTS resistant strains causing further treatment failure.

Presence of Multidrug-Resistant <i>E. coli</i>, <i>Enterococcus</i>spp. and <i>Salmonella</i>spp. in Lakes and Fountains of Porto, Portugal

Urban lakes and fountains provide recreational activities that could facilitate the contact between humans, animals and biological agents. The objective of this work was to assess the water quality and safety of 17 lakes and 13 fountains in the city of Porto (Portugal), by detecting the presence of Escherichia coli, enterococci and Salmonella spp., and analyzing their antimicrobial resistance. (For more information,please refer to the pdf.)