Multidrug-resistant Salmonella Research Articles

The phenotypic and genotypic antimicrobial resistance patterns of Salmonella isolated from chickens and meat at poultry slaughterhouses in Japan and Thailand.

Poultry meat is a popular food consumed globally. However, poultry farming is a source of Salmonella contamination which causes human salmonellosis. This study aimed to estimate the prevalence and antimicrobial resistance (AMR) of Salmonella among chickens and meat at poultry slaughterhouses in province study areas in Thailand and Japan. Chicken meat and feces samples were collected in Thailand and Japan. In Nakhon Ratchasima Province, Thailand, 558 samples were obtained from slaughterhouses from January 2021 to March 2022. In Gifu Prefecture, Japan, 140 samples (70 each of intestinal contents and meat) were purchased from slaughterhouses from June to October 2022. For Salmonella detection, the samples were cultivated according to the International Organization for Standardization 6579:2002/AMD 1:2007 method and confirmed using polymerase chain reaction (PCR) and agglutination tests for serotyping. Isolated Salmonella were tested for AMR to nine antibiotics using the disk diffusion method. Selected phenotypic multidrug-resistant (MDR) isolates were evaluated for AMR genes (AMRGs) using PCR. Salmonella prevalence from chickens and meat at slaughterhouses in Thailand and Japan was 41.2% and 40.7%, respectively. All the Salmonella isolates in Japan were serotyped as Schwarzengrund, and no Salmonella isolates were resistant to the nine antibiotics tested. In contrast, most of the Thai Salmonella isolates from chicken cloacal swabs and meat were resistant to doxycycline (78.3%) and colistin (63.5%). The prevalence of MDR Salmonella (MDRS) in chickens and meat from Thailand and Japan was 29.1% (67/230) and 0% (0/57), respectively. However, the most frequent AMRGs found in MDRS in Thailand were extended-spectrum beta-lactamase-Temoneira (ESBL-TEM) (45.1%). All isolated Salmonella from Japan revealed a class 1 integron gene (Int-1). Phenotypic MDRS isolates from Thailand showed the greatest correlation to AMRG and ESBL-TEM. Although there were no phenotypic AMR Salmonella isolates found in Japan, they can be found associated with Int-1, which may carry other AMRGs within the gene cassettes.

The occurrence of multidrug-resistant Salmonella nagoya and other serovars in healthy commercial layers in Ilorin, Nigeria

The occurrence of drug-resistant non-typhoidal Salmonella (NTS) in poultry has serious economic implications for the poultry industry and has the potential to cause human Salmonellosis. This study, therefore, aimed to determine the circulating serovars of NTS and their antibiotic susceptibility patterns in poultry in Ilorin. This cross-sectional study was conducted from January to March 2015. A total of 420 samples (cloacal, n=140; fecal, n=140; feed, n=70, and water, n=70) were aseptically collected from live adult birds from 14 farms using a systematic random sampling technique. Salmonella was isolated using the ISO 6579 method. Antibiotic sensitivity testing of NTS serovars was performed using the Kirby Bauer disc – diffusion method and interpreted using the epidemiological cut-off (ECOFF) values. The prevalence of NTS in poultry was 7.4% (n=31). Feed samples were the most contaminated samples (42%, n=13/31). Faecal sample (32%, n=10/31), cloacal swabs (19.5%, n= 6/31), and water samples (6.5%, n=2/31) also contained NTS. There was a significant difference between NTS isolation rates between farms (p<0.05). Only 21 isolates purposively selected across farms and sample types were serotyped. Salmonella nagoya was the most prevalent (52%, n=11/21). Other serovars were Salmonella brijbhumi (5%, n=1/21); Salmonella enteritidis (5%, n=1/21); and Salmonella enterica subsp. enterica serovar 6, 8: z4 (19%, n=4/21). Four isolates (19%) were untypable. All isolates showed multidrug resistance. Most of the isolates were resistant to ampicillin (82.3%) and tetracycline (76.5%). Some isolates were resistant to cefotaxime (23.5%) and ciprofloxacin (29.4%). The occurrence of multidrug-resistant salmonella isolates is considered a critical public health threat that requires urgent global action. There is a need for a coordinated national salmonella surveillance program in Nigeria.

Radiation sensitivity and inactivation of antibiotic-resistant Salmonella spp. in fresh chicken legs

In the Philippines, a total of 21,000 typhoid cases with 40 deaths caused by Salmonella typhi were reported in 2016. Previous studies have shown that multi-drug resistant Salmonella (MDRS) exists in fresh chicken meat purchased from retail stalls and supermarkets. MDRS has become a global health concern because of its resistance to treatment with the usual battery of antibiotics. Some studies show that gamma irradiation can eliminate antibiotic-resistant bacteria in food. This study was aimed at determining the radiation sensitivity and inactivation of antibiotic-resistant Salmonella spp. in fresh chicken legs. In phase one, four strains of freshly prepared Salmonella spp. were identified for resistance/susceptibility using disk diffusion method and minimum inhibitory concentration (MIC) with a different spectrum of Ampicillin (AMP), Chloramphenicol (CHL), Gentamicin (GN), Tetracycline (TET) Sulfamethoxazole/Trimethoprim (STX), based on the breakpoints established by CLSI (Clinical and Laboratory Standards Institute). Results showed that the S. enterica ser. Enteritidis 1963, S. enterica ser. Typhi 1768 and S. enterica ser. Typhimurium 1741were resistant to AMP and GN, while S. enterica ser. Typhimurium ATCC 14028 was resistant to GN. In phase two, the freshly prepared pure strains of antibiotic-resistant Salmonella spp. were grown in tryptic soy broth (TSB) for 24 h, centrifuged, and cell pellets were re-suspended in phosphate buffer saline (PBS) and adjusted at 0.5 McFarland (1.0 × 108 CFU per mL). One ml of Salmonella spp. was inoculated into fresh chicken meat then irradiated at different doses of control (0, 0.2, 0.4, 0.6, 0.8 1.0, and 2.0 kGy) at the Gamma Irradiation Facility of the Philippine Nuclear Research Institute. The D10-values, for the four strains of Salmonella, ranged from 0.14 to 0.19 kGy. This indicates that low dose radiation can induce a 1-log reduction of Salmonella spp. in fresh chicken legs and at 2 kGy doses, effectively eliminate the Salmonella spp. by 6 logs cycle. The four strains of Salmonella were mostly resistant to AMP and GN. Therefore, S. enterica serovar Enteritidis 1963, S. enterica serovar Typhi 1768, and S. enterica serovar Typhimurium 1741 exhibited multi-drug resistance. Gamma radiation can be used as a feasible technique to inactivate the presence of Salmonella spp. including the antibiotic-resistant Salmonella in fresh chicken meat.

A Case of Salmonella Enterocolitis Unmasking Crohnʼs Disease

Introduction: Inflammatory bowel disease (IBD) and salmonella enterocolitis can initially be difficult to differentiate given overlap of clinical manifestations. We present a middle-aged female with cultureproven salmonella enterocolitis and bacteremia that did not improve with antibiotics and was found to have Crohn's disease (CD) on endoscopy. Case:A 44 year-old female with history of allergic rhinitis presented to an outside hospital for one week of abdominal pain, vomiting, and watery diarrhea. She purchased piglets around the same time and her husband and daughter had a similar diarrheal illness but recovered. She was found to be in septic shock and transferred to our hospital for a higher level of care. She was admitted to the ICU and treated with meropenem and ciprofloxacin for multi-drug resistant salmonella enterocolitis and bacteremia. As she began to improve, she was transferred to the floor but began having melena/hematochezia. EGD showed many superficial non-bleeding esophageal ulcers and colonoscopy revealed ulcerations from the distal ileum to the transverse colon. Rectal bleeding continued and required repeat colonoscopy with placement of two hemoclips to a bleeding vessel at hepatic flexure where severely friable and nodular mucosa of the right colon was found. Esophageal biopsies revealed HSV esophagitis and colon biopsies showed crypt architectural distortion and crypt abscesses suggestive of IBD. Given no improvement on antibiotics, she was started on prednisone for a presumed IBD flare with resolution of rectal bleeding. Discussion: IBD and infectious gastroenteritis, especially in the acute setting, may have similar presentations both clinically and endoscopically, making it difficult to distinguish the two entities. When present concomitantly, recognition is further complicated. Salmonella infections are usually self-limited with a short duration of symptoms. Although endoscopy is usually unnecessary for diagnosis, it should be performed if symptoms persist to pursue other etiologies, including IBD. Clinicians should have a high suspicion for concomitant disease, in the setting of an extended salmonella disease course unresponsive to antibiotics, as unidentified IBD patients are at increased risk for illness progression.

Changing Trends of Antibiotic Susceptibility Pattern of Salmonella typhi 11 and paratyphi in Recent Isolates

Due to lack of proper sanitation measures and clean water typhoid and paratyphoid fever is prevalent in developing counties like Bangladesh. Increasing number of cases of antibiotic resistance as well as multi-drug resistance have been reported in Indian sub-continent. A total of 120 patients selected for this study on the basis of clinical diagnosis. Among them salmonella typhi and paratyphi were isolated in 54 cases by blood culture. Among the isolates 100% sensitivity was present to third generation cephalosporines, gentamycine and carbapenems. Resistance to conventional antibiotics like chloramphenicol, ampicillin, amoxycillin, cotrimoxazole were decreasing which was encouraging. Multi-drug resistant salmonella strains were found in 11.11% cases. S. typhi and paratyphi isolates were highly sensitive to not commonly used antibiotics like gentamycine, ceftazidim and carbapenems. So a careful consideration should be taken before deciding the antibiotic for treatment of enteric fever patients in order to prevent the emergence of antibiotic resistance.

A study on clinico-epidemiological profile of typhoid fever in a rural based medical college & hospital; West Bengal; India

Introduction: Typhoid fever is estimated to have caused 26.9 million cases and 5.74 lakhs deaths worldwide in 2010. It remains a major public health problem in India and other part of developing world. Background: Non- provision of safe drinking water and sanitation measures, non-implementation of adequate vaccination strategies and emergence of multidrug resistant salmonella strains is responsible for why typhoid fever is till now remaining an important health problem in some parts of world and the disease is even becoming more complex. Objective: This study was conducted in a tertiary care centre to find out the clinico-epidemiological profile of patients admitted with typhoid fever. Design: Cross sectional observational study. S ubjects: 460 Widal positive typhoid fever pediatric cases admitted from 1st June 2016 to 30th November 2016. Methods: Both clinical and laboratory data of all the patients were retrieved, compiled and analyzed. Results: Out of 460 patients 238(51.74%) were males and 222(48.26%) were females. Fever (100%), vomiting (49.13%), diarrhea (30.21%), cough (30.0%) and hepatomegaly (73.26%) were commonly observed. Response to injection Ceftriaxone was excellent. 355(77.17%) patients responded to Ceftriaxone alone and 99(21.52%) patients needed addition of oral Azithromycin.Average hospital stays in our study ranged from 3-9 days. Conclusion: In the present series typhoid fever accounted for 10.94% of pediatric admissions. Though mortality has significantly reduced typhoid fever continues to be an important cause of hospitalization in pediatric population. High incidence among lower age group indicates high endemicity and emphasizes the need of widespread use of vaccination.

Recent Sensitivity Pattern of Salmonella Typhi in a Private Hospital

Introduction: Enteric fever is highly prevalent in Bangladesh. Multidrug resistant salmonella Typhi is emerging throughout the world as well as in Bangladesh. Observing recent sensitivity pattern will help in choosing proper empirical antibiotics in resource limited country like Bangladesh as culture facilities is not available throughout the country.Materials and Methods: The study included 86 S. typhi isolates from blood cultures of patients suffering from suspected typhoid fever who attended the outpatient clinics or were admitted in Islami Bank hospital in Dhaka during January 2015 to July 2017.Results: A total of 86 S. typhi isolates were included in the study. Mean age of the study population was 22.06±17.1 and there was male 44 (51.2%) predominance. All the isolates of S. typhi were sensitive to Meropenem. Highest resistance was observed against Amikacin (62.4%) closely followed by Co-timoxazole (48.4%) and Amoxiclav (46.5%). The S. typhi isolates showed low-level resistance against Ceftriaxone (1.16%), Cefuroxime (4.6%), Azithromycin(13.9%), Levofloxacin (11.6%).Conclusions: According to findings of this study it can be advised that oral form of Cefuroxime, Levofloxacin and Azithromycin can be used as a first line. Then if patient is nonresponsive Ceftriaxone might be used. Meropeman should be reserved for selective cases.J MEDICINE Jan 2018; 19 (1) : 15-17

Computational analysis and In-silico predictive modeling for inhibitors of PhoP regulon in S. typhi on high-throughput screening bioassay dataset.

The emergence of multidrug resistant salmonella enterica serotype typhi in pandemic proportions throughout the world and therefore there is a necessity to speed up the discovery of novel molecules having different modes of action and also less influenced to the resistance formation that would be used as drug for the treatment of salmonellosis particularly typhoid fever. The PhoP regulon is well studied and have now been shown to be critical regulator of number of gene expression whose required for intracellular survival of S.enterica and pathophysiology of disease like typhoid. The evident roles of two component PhoP/PhoQ-regulated products in salmonella virulence have motivated attempts to target them as therapeutically. Although the discovery process of biologically active compounds for the treatment of typhoid rely on hit finding procedure using high throughput screening technology alone is very expensive, as well as time consuming when performed on large scales. With the recent advancement in combinatorial chemistry and contemporary technique for compounds synthesis, there are more and more compounds become available that gives ample growth of diverse compound library, but the time and endeavor required to screen these unfocused massive and diverse library has been slightly reduced in the past years. Hence there is demand to improve the high quality hits and success rate for high-throughput screening (HTS) that required focused and biased compound library towards the particular target. Therefore we still need an advantageous and expedient method to prioritize the molecules that will be utilized for biological screens which save time and also inexpensive. In this concept In-silico methods like Machine Learning are widely applicable technique used to build computational model for high-throughput virtual screens to prioritize molecules for advance study. Furthermore in computational analysis we extended our study to identify the common enriched structural entities among the biologically active compound towards find out the privileged scaffold.

Characterization of Virulence Genes among Multidrug Resistant Salmonellae Isolated from Chickens

Multidrug resistant (MDR) pathogenic Salmonella species augment the frequency and severity of infection lead to treatment failure in both animals and humans. Occurrence of virulence determinant genes in MDR Salmonella species still lack and need more investigations. Therefore, this study was undertaken to find out the prevalence of MDR salmonellae and their virulence genes in diseased broiler. Thirty out of three hundred (10%) of chicken organs were infected with salmonellae. Salmonella. Typhimurium, S. Enteritidis, S. Birkenhead, S. Virchow, S . Kentucky, S . Arizona and S . Montevideo represented 46.7%, 20%, 3.3%, 3.3%, 10%, 10% and 6.7% of the examined serotypes, respectively. Antimicrobial susceptibility test of all salmonella isolates revealed that all salmonella isolates were sensitive to ciprofloxacin and chloramphenicol. Meanwhile, they were resistant to erythromycin, rifamycin and amoxicillin/clavulinic acid. S . birkenhead and S . typhimurium were the most resistant phenotypes. PCR results showed fli C and sef C genes were detected in Salmonella typhimurium and Salmonella Enteritidis, respectively. Furthermore, inv A, hil A, stn , sop B, pef A and spv C genes with percentages 100%, 88%, 53%, 41%, 41% and 6% among examined serotypes respectively. It could be concluded that multidrug resistant salmonellae contain at least one virulence gene.

Targeted highly sensitive detection of multi-drug resistant salmonella DT104 using gold nanoparticles

Monoclonal antibody-conjugated popcorn-shape gold nanotechnology-driven approach to selectively detect multiple drug resistant (MDRB) Salmonella typhimurium DT104 bacteria has been developed. We demonstrate that the gold nanotechnology based assay is capable of measuring the amount of MDRB in food samples.

An imported enteric fever caused by a quinolone-resistantSalmonella typhi

Recent reports indicate that nalidixic acid susceptibility correlates well with the clinical outcome of patients with Salmonella Typhi infection treated with quinolones. We report a case of enteric fever caused by S Typhi in which the isolate was resistant to nalidixic acid, but showed in vitro susceptibility to ciprofloxacin. Following treatment with ciprofloxacin, the clinical outcome was not satisfactory and the patient had a relapse. However, after using a higher dose of ciprofloxacin, the patient was cured. We recommend that all Salmonella systemic infections resistant to nalidixic acid with in vitro but decreased susceptibility to fluoroquinolones be treated with other antibiotics like third-generation cephalosporins or azithromycin. These patients should be closely followed up and observed for further relapse.

Resistance to Anti-Infective Drugs and the Threat to Public Health

Increasing resistance of pathogens to anti-infective drugs is an urgent public health problem that must be addressed through more prudent use of these drugs in human medicine and in animal husbandry, agriculture, and aquaculture.

OUTBREAKS OF MULTIDRUG-RESISTANT SALMONELLA TYPHIMURIUM ASSOCIATED WITH VETERINARY FACILITIES: IDAHO, MINNESOTA AND WASHINGTON, 1999.

OUTBREAKS OF MULTIDRUG-RESISTANT SALMONELLA TYPHIMURIUM ASSOCIATED WITH VETERINARY FACILITIES: IDAHO, MINNESOTA AND WASHINGTON, 1999.