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BACKGROUND: Environmental surveillance, using detection of Salmonella Typhi DNA, has emerged as a potentially useful tool to identify typhoid-endemic settings; however, it is relatively costly and requires molecular diagnostic capacity. We sought to determine whether S. Typhi bacteriophages are abundant in water sources in a typhoid-endemic setting, using low-cost assays. METHODOLOGY: We collected drinking and surface water samples from urban, peri-urban and rural areas in 4 regions of Nepal. We performed a double agar overlay with S. Typhi to assess the presence of bacteriophages. We isolated and tested phages against multiple strains to assess their host range. We performed whole genome sequencing of isolated phages, and generated phylogenies using conserved genes. FINDINGS: S. Typhi-specific bacteriophages were detected in 54.9% (198/361) of river and 6.3% (1/16) drinking water samples from the Kathmandu Valley and Kavrepalanchok. Water samples collected within or downstream of population-dense areas were more likely to be positive (72.6%, 193/266) than those collected upstream from population centers (5.3%, 5/95) (p=0.005). In urban Biratnagar and rural Dolakha, where typhoid incidence is low, only 6.7% (1/15, Biratnagar) and 0% (0/16, Dolakha) river water samples contained phages. All S. Typhi phages were unable to infect other Salmonella and non-Salmonella strains, nor a Vi-knockout S. Typhi strain. Representative strains from S. Typhi lineages were variably susceptible to the isolated phages. Phylogenetic analysis showed that S. Typhi phages belonged to the class Caudoviricetes and clustered in three distinct groups. CONCLUSIONS: S. Typhi bacteriophages were highly abundant in surface waters of typhoid-endemic communities but rarely detected in low typhoid burden communities. Bacteriophages recovered were specific for S. Typhi and required Vi polysaccharide for infection. Screening small volumes of water with simple, low-cost (~$2) plaque assays enables detection of S. Typhi phages and should be further evaluated as a scalable tool for typhoid environmental surveillance.

Bacteriocins are antimicrobial peptides produced by bacteria to prevent the growth of pathogens. Combining bacteriocins with metal nanoparticles, like silver nanoparticles (AgNPs), has developed into a viable strategy to get over bacteriocin limitations. In this study, bacteriocin BacZY05 was extracted from Bacillus subtilis ZY05 and purified using various techniques. The resulting purified bacteriocin was then combined with silver nanoparticles to form bacteriocin silver nanoconjugates (BacZY05-AgNPs). The physicochemical properties of the BacZY05-AgNPs were characterized using various analytical techniques. The mean diameter of the synthesized AgNPs was approximately 20–60 nm with an oval or spherical shape. The antimicrobial activity of the BacZY05-AgNPs was evaluated against several indicator strains by their zone of inhibition (ZOI), using the agar well diffusion method. Compared to bacteriocin (ZOI- 13 to 20 mm) and AgNPs (ZOI- 10–22 mm) alone, the antibacterial activity data demonstrated a 1.3-1.5-fold increase in the activity of bacteriocin-nanoconjugates (ZOI- 22 to 26 mm). For Staphylococcus aureus MTCC3103 and Klebsiella pneumoniae MTCC109, BacZY05-capped AgNPs exhibited the lowest minimum inhibitory concentration (MIC), measuring 10.93 µg/mL. For Salmonella typhi NCIM2501, the MIC was 28.75 µg/mL. The highest MIC value was 57.5 µg/mL for Escherichia coli DH5α and Vibrio cholerae MTCC3909. With BacZY05-capped AgNPs, the lowest minimum bactericidal concentration (MBC) of 28.75 µg/mL was observed for Staphylococcus aureus MTCC31003. In the cases of Salmonella typhi NCIM2501 and Klebsiella pneumoniae MTCC109 concentration was 57.5 µg/mL. Vibrio cholerae MTCC3909 and Escherichia coli DH5α had the highest MBC values at 115 µg/mL. [ABSTRACT FROM AUTHOR]

The speciation of Salmonella occurred by acquisition of genomic islands from other bacterial species and continued to diverge into subspecies and serovars with diferent range of host. S. enterica serovar Typhimurium (STM) is a generalist pathogen infecting hosts that include birds, mice, and humans, whilst S. enterica serovar Typhi (STY) is a restricted-host pathogen, infecting only humans. Despite their ranges of hosts, STM and STY possess 97-98% identity. Gain of genes by horizontal transference and loss of genes by mutations, are believed essential for differentiation of Salmonella. Salmonella pathogenicity island 3 (SPI-3) is an example combining these two processes. SPI-3 encodes misL and marT, among other genes. In STM, misL is required for gut colonization. Furthermore, protein MarT, positively regulates expression of misL by binding to misL-promoter. On the other hand, in SPI-3 of STY, marT and misL are pseudogenes. Interestingly, the gene t3766 (gene involved in resistance to H2O2) is present only in STY and is negatively regulated when marTSTM is heterologously expressed in STY. Based on the view that MarT might regulate genes implicated in virulence, this work searched for new genes regulated by MarT. In silico searches for possible MarT target genes were performed, and 4 genes were selected for further analysis as they contained at least 2 copies of the consensus MarT-binding sequence in their promoters. Mutating marT in STM or heterologously expressing marTSTM in STY confirmed that MarT negatively regulates ORF STY1408 or STM14_2003, its homologue in STM. STY1408 encodes for a putative protein with homology to methyl accepting chemotaxis proteins, which participate in chemotaxis and motility. Therefore, STY1408 was named mrmI (MarT-regulated motility gene I). Motility assays confirmed that the product of mrmI modulates motility. In addition, in vitro infection of cells with STM and STY mutants in mrmI reduces association with cells at 1, 3 and 24 h post-infection. Oral infection of mice showed that a mrmI null mutant was defective in producing systemic disease. Therefore, we conclude that MarT regulated mrmI, is involved in virulence of Salmonella. While pseudogenization of marT might modulate the fitness of narrow host range STY. [ABSTRACT FROM AUTHOR]

Background In Santiago, Chile, where typhoid had been hyperendemic (1977–1991), we investigated whether residual chronic carriers could be detected among household contacts of non-travel-related typhoid cases occurring during 2017–2019. Methods Culture-confirmed cases were classified as autochthonous (domestically acquired) versus travel/immigration related. Household contacts of cases had stool cultures and serum Vi antibody measurements to detect chronic Salmonella Typhi carriers. Whole genome sequences of acute cases and their epidemiologically linked chronic carrier isolates were compared. Results Five of 16 autochthonous typhoid cases (31.3%) were linked to 4 chronic carriers in case households; 2 cases (onsets 23 months apart) were linked to the same carrier. Carriers were women aged 69–79 years with gallbladder dysfunction and Typhi fecal excretion; 3 had highly elevated serum anti-Vi titers. Genomic analyses revealed close identity (≤11 core genome single-nucleotide polymorphism [SNP] differences) between case and epidemiologically linked carrier isolates; all were genotypes prevalent in 1980s Santiago. A cluster of 4 additional autochthonous cases unlinked to a carrier was identified based on genomic identity (0-1 SNPs). Travel/immigration isolate genotypes were typical for the countries of travel/immigration. Conclusions Although autochthonous typhoid cases in Santiago are currently rare, 5 of 16 such cases (31.3%) were linked to elderly chronic carriers identified among household contacts of cases. [ABSTRACT FROM AUTHOR]

Food‐related stresses such as heating and freezing may influence the biofilm formation ability of bacteria. This study aimed to investigate the main and interactive effects of food‐related stresses on the biofilm formation potential of Salmonella strains isolated from meat. Salmonella enteritidis, Salmonella typhi, and Salmonella typhimurium were subjected to osmotic, acid, heat, cold, and freezing stresses. The colorimetric microtiter plate method was used to measure the biofilm formation ability as a response to the stresses. Among the main effects, freezing time had the most significant effect on the biofilm formation responses of three Salmonella serovars. Freezing reduced the biofilm formation ability of Salmonella typhimurium and Salmonella enteritidis but increased that of Salmonella typhi (p < 0.05). Among the interaction effects, the most significant effect on the biofilm formation response of Salmonella typhi was the interaction between pH and heat, which had a negative effect on the biofilm formation response. In contrast, the interaction between osmotic pressure and cold stresses was the most significant interactive effect on the biofilm formation responses of Salmonella enteritidis and Salmonella typhimurium, which had an increasing effect. This study concluded that the food‐related stresses could change the biofilm formation capacity of Salmonella serotypes, and each serotype might show different biofilm formation abilities in response to different stresses. [ABSTRACT FROM AUTHOR]

Bacterial contamination in fruits and vegetables cultivated in urban and peri-urban areas constitutes a serious public health risk. This paper investigates bacterial contamination in irrigation water of the Nairobi-Machakos counties interface, Kenya. Sixty-six irrigation water samples were tested for total coliforms, Escherichia coli, Shigella spp. Pseudomonas aeruginosa, Enterococcus faecalis, Vibrio cholerae, Salmonella typhi, BOD, COD, and pH. Results show a high load of bacterial pathogens in all samples except for Salmonella typhi, which tested negative. Based on Kenya's standards and WHO guidelines, the irrigation water samples are unfit for fruit and vegetable irrigation. Urgent and effective measures are required, including regular monitoring, sensitisation, and enforcement of phytosanitary and regulatory measures. [ABSTRACT FROM AUTHOR]

Background: Typhoid fever caused by Salmonella enterica serovar Typhi (S. typhi) continues to pose a significant risk to public health in developing countries, including Pakistan. This study investigated the epidemiological factors linked to suspected and confirmed S. typhi infections in Peshawar's hospital population. Methodology: A total of 5735 blood samples of patients with suspected enteric fever were collected from September 2022 to November 2023. S. typhi infection was confirmed using microbiological culture of blood samples, biochemical-based tests, and DNA-sequencing methods. Drug sensitivity testing on cultures was conducted as per the CLSI guidelines. Chi-square tests were used to analyze the clinical and epidemiologic characteristics of 5735 samples stratified by S. typhi infection status, and risk factors were assessed by applying logistic regression models to estimate odds ratios (ORs). Results: The number of confirmed typhoid fever cases in this hospital-based study population was 691 (/5735, 12.0%), more prevalent in males (447/3235 13.8%) and children (0–11 years) (429/2747, 15.6%). Compared to children, the risk of S. typhi infection was lower in adolescence (adjusted OR = 0.52; 95% CI: 0.42–0.66), adulthood (19–59 years; aOR = 0.30; 95% CI: 0.25–0.38), and older adulthood (aOR = 0.08; 95% CI: 0.04–0.18) (p < 0.001). Compared to males, the risk of S. typhi infection was lower in females (aOR = 0.67; 95% CI = 0.56–0.80; p = 0.002). Living in a rural residence (compared to urban) was associated with a higher risk of infection (aOR = 1.38; 95% CI: 1.16–1.63; p = 0.001), while access to a groundwater source (compared to municipal water supply) led to a lower risk (aOR = 0.56; 95% CI: 0.43–0.73; p = 0.002). Vaccination demonstrated a robust protective effect (aOR = 0.069; 95% CI = 0.04–0.11, p = 0.002). For those with typhoid infections, clinical biomarker analysis revealed the presence of leucopenia (65/691, 9.4%), thrombocytopenia (130/691, 18.8%), and elevated alanine aminotransferase (ALT) (402/691, 58.2%) and C-reactive protein (CRP) (690/691, 99.9%) levels. Worryingly, among the positive S. typhi isolates, there was a high prevalence of drug resistance (653/691), including multidrug-resistant (MDR 82/691, 11.9%) and extensively drug-resistant types (XDR, 571/691, 82.6%). Conclusions: This study highlights the importance of age, sex, locality, water source, and vaccination status in shaping the epidemiological landscape of S. typhi in the Peshawar district. It implies that expanding vaccination coverage to the broader population of Khyber Pakhtunkhwa province, particularly in the district of Peshawar, would be beneficial. [ABSTRACT FROM AUTHOR]

Salmonella Typhi is a human-restricted pathogen that is transmitted by the faecal–oral route and causative organism of typhoid fever. Using health facility data from 2016 to 2020, this study focuses on modelling the spatial variation in typhoid risk in Ndirande township in Blantyre. To pursue this objective, we developed a marked inhomogeneous Poisson process model that allows us to incorporate both individual-level and environmental risk factors. The results from our analysis indicate that typhoid cases are spatially clustered, with the incidence decreasing by 54% for a unit increase in the water, sanitation, and hygiene (WASH) score. Typhoid intensity was also higher in children aged below 18 years than in adults. However, our results did not show evidence of a strong temporal variation in typhoid incidence. We also discuss the inferential benefits of using point pattern models to characterise the spatial variation in typhoid risk and outline possible extensions of the proposed modelling framework. [ABSTRACT FROM AUTHOR]

Invasive non-typhoidal Salmonella (iNTS) disease is an under-recognized high-burden disease causing major health and socioeconomic issues in sub-Saharan Africa (sSA), predominantly among immune-naïve infants and young children, including those with recognized comorbidities such as HIV infection. iNTS disease is primarily caused by Salmonella enterica serovar Typhimurium sequence type (ST) 313 and 'African-restricted clades' of Salmonella Enteritidis ST11 that have emerged across the African continent as a series of epidemics associated with acquisition of new antimicrobial resistance. Due to genotypes with a high prevalence of antimicrobial resistance and scarcity of therapeutic options, these NTS serovars are designated by the World Health Organization as a priority pathogen for research and development of interventions, including vaccines, to address and reduce NTS associated bacteremia and meningitis in sSA. Novel and traditional vaccine technologies are being applied to develop vaccines against iNTS disease, and the results of the first clinical trials in the infant target population should become available in the near future. The "Vaccine Value Profile" (VVP) addresses information related predominantly to invasive disease caused by Salmonella Enteritidis and Salmonella Typhimurium prevalent in sSA. Information is included on stand-alone iNTS disease candidate vaccines and candidate vaccines targeting iNTS disease combined with another invasive serotype, Salmonella Typhi, that is also common across sSA. Out of scope for the first version of this VVP is a wider discussion on either diarrheagenic NTS disease (dNTS) also associated with Salmonella Enteritidis and Salmonella Typhimurium or the development of a multivalent Salmonella vaccines targeting key serovars for use globally. This VVP for vaccines to prevent iNTS disease is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic, and societal value of pipeline vaccines and vaccine-like products. Future versions of this VVP will be updated to reflect ongoing activities such as vaccine development strategies and a "Full Vaccine Value Assessment" that will inform the value proposition of an iNTS disease vaccine. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the World Health Organization African Region. All contributors have extensive expertise on various elements of the iNTS disease VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information. [ABSTRACT FROM AUTHOR]

Background: Understanding the source of typhoid infections and the genetic relatedness of Salmonella Typhi (S. Typhi) by cluster identification in endemic settings is critical for establishing coordinated public health responses for typhoid fever management. This study investigated the genotypic diversity, antibiotic resistance mechanisms, and clustering of 35 S.Typhi strains isolated from cases and carriers in the Mukuru Informal Settlement. Methods: We studied 35 S.Typhi isolates, including 32 from cases and 3 from carriers, from study participants in the informal settlement of Mukuru, Nairobi, Kenya. Genomic DNA was extracted, and whole-genome sequencing (WGS) was performed to determine the phylogenetic relatedness of strains and detect antimicrobial resistance determinants (AMR). WGS data were analyzed using bioinformatics tools available at the Center for Genomic Epidemiology and Pathogenwatch platforms. Results: Genotype 4.3.1.2 EA3 was found to be dominant at 46% (16/35), followed by 4.3.1.2 EA2 at 28% (10/35), and 4.3.1.1 EA1 at 27% (9/35). A comparison of the isolates with global strains from Pathogenwatch identified close clustering with strains from Uganda, Tanzania, Rwanda, and India. Three isolates (9%) distributed in each cluster were isolated from carriers. All genotype 4.3.1.2 EA3 isolates were genotypically multidrug-resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. Single mutations in the quinolone resistance-determining region were identified in the gyrA (S83Y) and gyrB (S464F) genes. All isolates associated with multidrug resistance showed the presence of the IncQ1 plasmid with the following genes: blaTEM-1B, catA1, sul1, sul2, and dfrA7. Conclusion: The close phylogenetic relatedness between antimicrobial-resistant case isolates and carriage isolates indicates that typhoid carriage is a possible source of infection in the community. Comparative analysis with global isolates revealed that the Kenyan isolates share common lineages with strains from neighboring East African countries and India, suggesting regional dissemination of specific MDR clones. AMR was a major feature of the isolates. Surveillance and testing for antimicrobial susceptibility should inform options for the management of cases. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the epidemiology, clinical features, and complications of extensively drugresistant Salmonella typhi (XDR S. typhi) infection in adults. Method: This cross-sectional study enrolled adults with culture-proven XDR S. typhi admitted to Hayatabad Medical Complex, Peshawar from 1st March to 10th September 2022. Their demographic characteristics, clinical features, treatment, and complications were recorded. Results: Out of 84 patients, 68 (80.9%) were male. The mean age of enrolled patients was 25.2 ± 11.3 years. The mean duration of fever at the time of admission was 13.6 ± 8.2 days, respectively. The most common symptom was loose stools (n=25, 29.8%). Most of the patients (n=69, 82.1%) had received empirical treatment before hospitalization. The majority of the patients (n=42, 50%) received meropenem and a combination of meropenem and azithromycin (n=35, 41.7%) during the study. The time to defervescence for both regimens was similar. Five patients (6%) developed complications of enteric fever. There was no mortality among the participants. Conclusions: Diarrhea was the most common associated clinical feature in XDR typhoid fever. Most of the patients received meropenem alone or in combination with azithromycin with a comparable time to defervescence. The majority of the patients recovered uneventfully and there was no mortality among the study participants. [ABSTRACT FROM AUTHOR]

Objectives: To determine the antimicrobial activity of silver nano-particles(AgNPs) with tetracycline and ampicillin against multi-drug resistance (MDR) and extensively-drug resistance (XDR) Salmonella typhi. Methods: Cross sectional non-probability purposive study was conducted from September, 2021 to May, 2022 at Microbiology department PNS Shifa, Hospital Karachi. Blood cultures of patients suspicious of typhoid fever were collected and incubated in automated Bact/Alert system. Positive cultures were identified on blood and MacConkey and processed by API-10S, confirmed by serotyping (O9 antisera) (SSI Diagnostica's Salmonella). Antibiotic resistance was done by Kirby-Bauer disk diffusion (Sigma and Rich). MDR and XDR isolates were preserved in Brain Heart Infusion in a volume of 2ml in screw capped bottles at -70°C. Antimicrobial powders (ampicillin and tetracycline (Alfa Aesar) weighed by an electrical weighing balance (OHAUS) to take 1mg of antimicrobial drug. Absorbance spectra of serial concentrations of antibiotics (UV-Vis spectrophotometer (Mole-Qule-) AgNPs (10nm) (nanocomposix) + Antibiotic in (1:1 volume ratio). Conjugation of silver nanoparticles with tetracycline and ampicillin was done by FTIR (thermos scientificThermos ScientificNicolet 50). Results: Out of 77 isolates, 54 were resistant to ceftriaxone (XDR) and 23 sensitive to ceftriaxone (MDR). All isolates were susceptible to azithromycin and meropenem. Comparison of zone of inhibitions of ampicillin and Amp-AgNPsas and tetracycline with Tet-AgNPs was done. Minimal inhibitory concentration was also done to determine antimicrobial activity. Conclusion: Significant synergistic inhibitory effects against Salmonella Typhi isolates were obtained by combination of tetracycline with silver nano-particles even at low concentration. [ABSTRACT FROM AUTHOR]

This investigation was applied to isolate and identify bacteria in three different restaurants order to predict their effects on people. Power plate method for isolation of bacteria the samples were inoculated into nutrient agar media by streak plate technique to obtain well isolated colonies. The results show the identity and the total colony forming units (CFU) for bacteria. The most frequently isolated bacteria were the bacterial species: Bacillus cereus, Clostridium botulinum, Escherichia coli, Salmonella typhi, Shigella dysenteriae, Staphylococcus aureus and Lactobacillus subtilus (11.12, 8.24, 20.11,17.32, 17.01, 10.31 and 8.27) % respectively. According to the bacteria the higher numbers of bacteria were isolated on menu and containers. [ABSTRACT FROM AUTHOR]

Marine organisms are vast sources of bioactive components, with holothorians, or sea cucumbers being one of these sources. Therefore, sea cucumber specimens were examined as a promising source of natural substances that can be used as antibacterial, antifungal, anti-inflammatory, antioxidant, antiviral, and antitumor agents. Holothuria papillifera was collected from Zaafarana, Ras Ghareb, and Altur stations and employed as a biological weapon against some pathogens. H. papillifera extracts showed high activity as antibacterial extracts against Staph. aureus and Enterococcus faecalis (Gram+ve), Escherichia coli, Salmonella typhi, and Klebsiella pneumoniae (Gram-ve). It also exhibited positive antifungal efficacy against Candida albicans and revealed moderate activity against liver cancer cells and a weak activity against breast cancer cells. Alternatively, H. papillifera crude extract has weak antiviral activity against CoxB4 and very weak antiviral efficacy against HAV (hepatitis A virus). Moreover, our results proved that H. papillifera extract had anti-inflammatory effects and exhibited antioxidant power. In conclusion, H. papillifera has broad antimicrobial activity against many pathogens, as well as antioxidant, antitumor, anti-inflammatory, among others. It is recommended to explain and characterize the composition of the bioactive compounds of H. papillifera to be included in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate antidiarrheal potential of prickly pear cladode and its hepatoprotective role in different groups of diarrhea‐induced mice. Mice received cefixime (4 mg/kg of bw) and different concentrations of aqueous cladode extract (250 mg/kg of bw, 500 mg/kg of bw and 1000 mg/kg of bw). Feces Salmonella typhi ATCC 19430 was used to assess antidiarrheal potential and hematological, biochemical parameters, and histopathological analyses were carried out for 17 days. The results showed that administration of Salmonella typhi ATCC 19430 in mice produced liver injuries with histological damage, whereas 1000 mg/kg of bw cladode extract reduced the Salmonella typhi ATCC 19430 load of feces earlier as compared to the other groups during 17 days. Hematological parameters, like red blood cells (RBCs) (6.19 ± 1.85 × 106/mm3) and hemoglobin (Hb) (10.06 ± 2.03 g/dL), of negative control group decreased, while white blood cells (WBCs) (13.46 × 106/mm3) increased from reference values. In lipid profile, low‐density lipoprotein (LDL) (9.0 ± 2.41 mg/dL), high‐density lipoprotein (HDL) (6.07 ± 2.45 mg/dL) and total cholesterol (TC) (35.22 ± 8.29 mg/dL) of negative control group decreased, while triglycerides (TG) (168.35 ± 71.75 mg/dL) increased from reference values. Alanine transferase (ALT) (60.30 ± 20.33 IU/L), alkaline phosphatase (ALP) (359.9 ± 100.05 IU/L) and aspartate transferase (AST) (168.77 ± 66.61 IU/L) of negative control group increased from reference values. Urea (27.36 ± 10.54 mmol/L) and creatinine (35.29 ± 12.15 mmol/L) of the negative control group increased. Cefixime also ameliorated injuries due to the administration of Salmonella typhi ATCC 19430. Conclusively, these findings indicated that pure aqueous extract of cladode showed more promising results regarding antidiarrheal potential. Hence, cladode might be used in food and supplement formulations as a functional ingredient. [ABSTRACT FROM AUTHOR]

Salmonella Typhi infection is showing as a negative alarm for human health due to the occurrence of life-threatening typhoid fever and the emergence of antibiotic resistance. The infection becomes chronic due to the biofilm formation of S. Typhi, which plays a significant role in antibiotic resistance. The S. Typhi can survive under various stress conditions such as antibiotic stress, host immune stress, environmental stress, and nutritional stress in the biofilm stage. Biofilm provides a protective cover to the S. Typhi and prevents the entry of antibiotics inside the bacterial cells. Thus, biofilm is the root cause of the problem. Therefore, this study explores the easy detection of S. Typhi biofilms using safranin dye with specific concentrations. We performed the biofilm growth kinetics, qualitative assessment of the biofilm formations, and safranin interactions to finalize the specific concentrations of safranin (0.5 mg/mL) to detect the S. Typhi biofilm condition. The study was validated at 0.5 mg/mL safranin concentrations with the help of RSM analysis and kinetics study of the typhoidal biofilm. The study is important because the obtained results indicated the precise detection of S. Typhi biofilm, which is useful for all phases of biofilm detection. The study provided new directions for typhoidal biofilm staining that could be an emerging methodology in the area of health sciences. [ABSTRACT FROM AUTHOR]

The objective of this paper was to assess the antimicrobial potency of unripe plantain fruits and peelings extracts against Escherichia coli, Staphylococcus aureus and Salmonella typhi using disc diffusion technique, with ciprofloxacin as control. The Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) were determined using 100 mg/ml, 75 mg/ml, 50 mg/ml and 25 mg/ml concentrations of each extract. Phytochemicals detected in the extracts were flavonoids, glycosides, tannins, alkaloids and phenol. All isolates were susceptible to the extract at the highest concentration of 100 mg/ml. At the lowest concentration of 25 mg/ml, E. coli showed resistance, while Salmonella typhi and Staphylococcus aureus showed intermediate resistance to the extract. The MIC and MBC of the extract on the test organisms were 14 and 20 mg/ml for E. coli; 25 and 16 mg/ml for Salmonella typhi whereas it was 100 mg/ml and 15 mg/ml for Staphylococcus aureus. E. coli was more susceptible to the extract and Staphylococcus aureus was the least. The results revealed the presence of phytochemicals with antimicrobial properties against E. coli, Staphylococcus sp. and Salmonella sp. Thus, unripe plantain fruits and peelings could be harnessed for the control of E. coli, Staphylococcus aureus and Salmonella sp., as natural antibiotics. [ABSTRACT FROM AUTHOR]

Centella asiatica phytocompounds coated onto Multi‐Walled Carbon Nanotube (MWCNT) possessing antibacterial activity were prepared using a simple physical absorption method. The incorporation of Centella asiatica phytocompounds into functionalized MWCNTs could improve the physical properties of Centella asiatica phytocompounds conjugated MWCNT compared to pure MWCNT. Fourier Transform Infrared Spectroscopy (FTIR) results depict the presence of bioactive compounds on MWCNT coatings and the Raman spectrum confirms the presence of carbon in various ranges by their peaks from 636 to 1594.46 cm−1 in the MWCNT. Scanning Electron Microscope (SEM) micrograph images confirmed the existence of MWCNT‐Nano composites with Centella asiatica phytocompounds exhibiting the surface structure with pore clarity and visible pipes. Transmission Electron Microscope (TEM) images show the uniform dispersed spherical ultrathin nanosheets at the size of 10–20 nm. Further anti‐bacterial analysis results revealed that Centella asiatica phytocompounds coating enhances the anti‐bacterial activity of MWCNT. Prepared Centella asiatica phytocompounds ‐MWCNT possess maximal inhibition and produces high zones of inhibition 11 ± 0.06, 17 ± 0.08, 14 ± 0.07, and 16 ± 0.08 mm against four food‐spoiling bacterial clinical pathogens Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia respectively. Centella asiatica phytocompounds conjugated‐MWCNT spin‐coated packaging showed good preservation properties. Centella asiatica phytocompounds conjugated with MWCNTs provide antimicrobial properties, enabling the development of novel food packaging materials that can protect food from spoilage, increase food stability, and sustainability, and improve the shelf life of food. [ABSTRACT FROM AUTHOR]

Background: Salmonella typhi is a specific strain of the Salmonella bacterium, responsible for triggering typhoid fever; a significant public health concern in developing nations. Objective: The current study aimed to identify the bacteria from the gallbladder, taken during cholecystectomies of patients, by isolating Salmonella typhi and by using microscopic characteristics, biochemical and polymerase chain reaction (PCR) tests. Methods: A total of 120 specimens were collected from the Baghdad Teaching Hospital, Iraq. A cross-sectional descriptive study was carried out from October, 2021, to July, 2022. During that study, 26 (54.2%) male patient tested positive for Salmonella typhias well as 22 (45.8%) female patients. The age of the patients varied from < 30 to > 60 years. p-value > 0.05 was considered significant to confirm a relationship between age and Salmonella typhi effect for patients. Results: Out of the 120 blood samples taken for this study, 48 (40%) tested positive by use of PCR test, 40 (33.3%) tested positive by use of the Widal test, 35 (29.1%) were positive for biopsy culture, and 35 (29.1%) were positive for blood culture. All Salmonella typhi isolates were found to be sensitive to the imipenem, cefepime, and ceftriaxone, but were resistant to gentamycin, ciprofloxacin, amikacin, erythromycin, and tetracycline (72%, 29%, 43%, 100%, 100%, respectively). Conclusions: The real time polymerase chain reaction (RT-PCR) tests and the Vitek 2 compact system showed a high level of accuracy in the detection of Salmonella typhi. Multidrug resistance was observed, which should be a signal to reduce antibiotic consumption [ABSTRACT FROM AUTHOR]

INTRODUCTION: Salmonella Typhi and Salmonella Paratyphi, fecal-oral transmitted bacterium, have temporally and geographically heterogeneous pathways of transmission. Previous work in Kathmandu, Nepal implicated stone waterspouts as a dominant transmission pathway after 77% of samples tested positive for Salmonella Typhi and 70% for Salmonella Paratyphi. Due to a falling water table, these spouts no longer provide drinking water, but typhoid fever persists, and the question of the diseases dominant pathway of transmission remains unanswered. METHODS: We used environmental surveillance to detect Salmonella Typhi and Salmonella Paratyphi A DNA from potential sources of transmission. We collected 370, 1L drinking water samples from a population-based random sample of households in the Kathmandu and Kavre Districts of Nepal between February and October 2019. Between November 2019 and July 2021, we collected 380, 50mL river water samples from 19 sentinel sites on a monthly interval along the rivers leading through the Kathmandu and Kavre Districts. We processed drinking water samples using a single qPCR and processed river water samples using differential centrifugation and qPCR at 0 and after 16 hours of liquid culture enrichment. A 3-cycle threshold (Ct) decrease of Salmonella Typhi or Salmonella Paratyphi, pre- and post-enrichment, was used as evidence of growth. We also performed structured observations of human-environment interactions to understand pathways of potential exposure. RESULTS: Among 370 drinking water samples, Salmonella Typhi was detected in 7 samples (1.8%) and Salmonella Paratyphi A was detected in 4 (1.0%) samples. Among 380 river water samples, Salmonella Typhi was detected in 171 (45%) and Salmonella Paratyphi A was detected in 152 (42%) samples. Samples located upstream of the Kathmandu city center were positive for Salmonella Typhi 12% of the time while samples from locations in and downstream were positive 58% and 67% of the time respectively. Individuals were observed bathing, washing clothes, and washing vegetables in the rivers. IMPLICATIONS: These results suggest that drinking water was not the dominant pathway of transmission of Salmonella Typhi and Salmonella Paratyphi A in the Kathmandu Valley in 2019. The high degree of river water contamination and its use for washing vegetables raises the possibility that river systems represent an important source of typhoid exposure in Kathmandu.

Abstract Background Understanding the source of typhoid infections and the genetic relatedness of Salmonella Typhi (S. Typhi) by cluster identification in endemic settings is critical for establishing coordinated public health responses for typhoid fever management. This study investigated the genotypic diversity, antibiotic resistance mechanisms, and clustering of 35 S.Typhi strains isolated from cases and carriers in the Mukuru Informal Settlement. Methods We studied 35 S.Typhi isolates, including 32 from cases and 3 from carriers, from study participants in the informal settlement of Mukuru, Nairobi, Kenya. Genomic DNA was extracted, and whole-genome sequencing (WGS) was performed to determine the phylogenetic relatedness of strains and detect antimicrobial resistance determinants (AMR). WGS data were analyzed using bioinformatics tools available at the Center for Genomic Epidemiology and Pathogenwatch platforms. Results Genotype 4.3.1.2 EA3 was found to be dominant at 46% (16/35), followed by 4.3.1.2 EA2 at 28% (10/35), and 4.3.1.1 EA1 at 27% (9/35). A comparison of the isolates with global strains from Pathogenwatch identified close clustering with strains from Uganda, Tanzania, Rwanda, and India. Three isolates (9%) distributed in each cluster were isolated from carriers. All genotype 4.3.1.2 EA3 isolates were genotypically multidrug-resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. Single mutations in the quinolone resistance-determining region were identified in the gyrA (S83Y) and gyrB (S464F) genes. All isolates associated with multidrug resistance showed the presence of the IncQ1 plasmid with the following genes: blaTEM-1B, catA1, sul1, sul2, and dfrA7. Conclusion The close phylogenetic relatedness between antimicrobial-resistant case isolates and carriage isolates indicates that typhoid carriage is a possible source of infection in the community. Comparative analysis with global isolates revealed that the Kenyan isolates share common lineages with strains from neighboring East African countries and India, suggesting regional dissemination of specific MDR clones. AMR was a major feature of the isolates. Surveillance and testing for antimicrobial susceptibility should inform options for the management of cases.

The study presents the data on organization of laboratory testing of clinical and environmental samples within the framework of establishing the etiology of the acute intestinal infections outbreak, performed by the specialists of the joint SAET of the Rospotrebnadzor in Dolisie (Republic of the Congo) in the period of 07–24 July, 2023.Materials and methods. In order to identify the causative agents of cholera and other acute intestinal infections of bacterial and viral nature, 177 clinical and environmental samples were tested, as well as cultures on solid nutrient media and bacterial suspensions. A total of 1023 tests were carried out by polymerase chain reaction (PCR) and 305 – using bacteriological method.Results and discussion. The causative agent of cholera has not been detected in any of the samples tested. Using the PCR method, markers of acute intestinal diseases agents (Salmonella spp., Shigella spp., Campylobacter spp., Rotavirus A) have been identified in 23 clinical samples and 1 sample of bacterial suspension. No DNA/RNA of pathogens has been detected in environmental samples. During culture studies, Salmonella enterica serovar Typhi have been isolated from 8 clinical samples, and their antibiotic sensitivity has been determined. Applying whole-genome nanopore sequencing, using the MinIon platform (Oxford Nanopore Technologies, UK), nucleotide sequences of 4 S. Typhi isolates have been investigated and deposited in the international database NCBI GenBank (No. CP141260, CP141193, CP141194, CP141195). Additionally, the analysis of initially sterile samples (blood, peritoneal fluid, intraoperational samples) from the patients of General and Reference hospitals of Dolisie has resulted in the identification of 5 cultures of non-fermenting bacteria, and their antibiotic sensitivity has been determined.

BACKGROUND: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000). METHODS: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch. RESULTS: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal sentinel surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes. CONCLUSIONS: The consortiums aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies. FUNDING: No specific funding was awarded for this meta-analysis. Coordinators were supported by fellowships from the European Union (ZAD received funding from the European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 845681), the Wellcome Trust (SB, Wellcome Trust Senior Fellowship), and the National Health and Medical Research Council (DJI is supported by an NHMRC Investigator Grant [GNT1195210]).

Antimicrobial resistance (AMR) poses a serious threat to the clinical management of typhoid fever. AMR in Salmonella Typhi (S. Typhi) is commonly associated with the H58 lineage, a lineage that arose comparatively recently before becoming globally disseminated. To better understand when and how H58 emerged and became dominant, we performed detailed phylogenetic analyses on contemporary genome sequences from S. Typhi isolated in the period spanning the emergence. Our dataset, which contains the earliest described H58 S. Typhi organism, indicates that ancestral H58 organisms were already multi-drug resistant (MDR). These organisms emerged spontaneously in India in 1987 and became radially distributed throughout South Asia and then globally in the ensuing years. These early organisms were associated with a single long branch, possessing mutations associated with increased bile tolerance, suggesting that the first H58 organism was generated during chronic carriage. The subsequent use of fluoroquinolones led to several independent mutations in gyrA. The ability of H58 to acquire and maintain AMR genes continues to pose a threat, as extensively drug-resistant (XDR; MDR plus resistance to ciprofloxacin and third generation cephalosporins) variants, have emerged recently in this lineage. Understanding where and how H58 S. Typhi originated and became successful is key to understand how AMR drives successful lineages of bacterial pathogens. Additionally, these data can inform optimal targeting of typhoid conjugate vaccines (TCVs) for reducing the potential for emergence and the impact of new drug-resistant variants. Emphasis should also be placed upon the prospective identification and treatment of chronic carriers to prevent the emergence of new drug resistant variants with the ability to spread efficiently. A phylogenetic analysis of Salmonella Typhi isolated from returning travelers to the United Kingdom between 1980 and 1995 suggests that H58 emerged from a chronic carrier in India in 1987 before spreading globally and was already multidrug resistant. [ABSTRACT FROM AUTHOR]

Background: Salmonella enterica serotype Typhi (Salmonella Typhi) causes severe and occasionally life-threatening disease, transmitted through contaminated food and water. Humans are the only reservoir, inadequate water, sanitation, and hygiene infrastructure increases risk of typhoid. High-quality data to assess spatial and temporal relationships in disease dynamics are scarce. Methods: We analyzed data from a prospective cohort conducted in an urban slum area of Dhaka City, Bangladesh. Passive surveillance at study centers identified typhoid cases by microbiological culture. Each incident case (index case) was matched to two randomly selected index controls, and we measured typhoid incidence in the population residing in a geographically defined region surrounding each case and control. Spatial clustering was evaluated by comparing the typhoid incidence in residents of geometric rings of increasing radii surrounding the index cases and controls over 28 days. Temporal clustering was evaluated by separately measuring incidence in the first and second 14-day periods following selection. Incidence rate ratios (IRRs) were calculated using Poisson regression models. Results: We evaluated 141 typhoid index cases. The overall typhoid incidence was 0.44 per 100,000 person-days (PDs) (95% CI: 0.40, 0.49). In the 28 days following selection, the highest typhoid incidence (1.2 per 100,000 PDs [95% CI: 0.8, 1.6]) was in the innermost cluster surrounding index cases. The IRR in this innermost cluster was 4.9 (95% CI: 2.4, 10.3) relative to the innermost control clusters. Neither typhoid incidence rates nor relative IRR between index case and control populations showed substantive differences in the first and second 14-day periods after selection. Conclusion: In the absence of routine immunization programs, geographic clustering of typhoid cases suggests a higher intensity of typhoid risk in the population immediately surrounding identified cases. Further studies are needed to understand spatial and temporal trends and to evaluate the effectiveness of targeted vaccination in disrupting typhoid transmission. Author summary: New generation typhoid conjugate vaccines have been introduced in mass national campaigns and routine immunization programs in several typhoid-endemic countries. We evaluated evidence for spatial and temporal clustering of typhoid fever in an urban slum area of Dhaka, Bangladesh, where typhoid is highly endemic. We assessed 141 typhoid index cases and observed the highest incidence of typhoid in the 14-day period following case selection in the population residing closest (cluster of radii 0-50m) to the index case. Clustering of incident cases suggests a higher intensity of transmission, and the populations at highest risk of contracting typhoid are those living in close proximity to an index case. The risk exists for a period of at least 28 days. Where strong surveillance exists, vaccination of localized geographic areas surrounding cases might be effective in controlling disease outbreaks in low- or no-coverage settings. This approach could offer a practical and efficient strategy for countries with limited data and resources to support mass typhoid vaccination. Additional evaluations of spatial and temporal trends of typhoid transmission are required in endemic and non-endemic settings, and studies designed to evaluate the effectiveness and impact of targeted vaccination are needed to refine prevention and control strategies. [ABSTRACT FROM AUTHOR]

Typhoid fever, caused by Salmonella enterica serovar typhi, presents a substantial global health threat, particularly in regions with limited healthcare infrastructure. The rise of multidrug-resistant strains of S. typhi exacerbates this challenge, severely compromising conventional treatment efficacy due to over activity of efflux pumps. In our study, a comprehensive exploration of two fundamental aspects to combat MDR in S. typhi is carried out; i.e. employing advanced bioinformatics analyses and AlphaFold AI, We successfully identified and characterised a putative homologue, ABC-TPA, reminiscent of the P-glycoprotein (P-gp) known for its role in multidrug resistance in diverse pathogens. This discovery provides a critical foundation for understanding the potential mechanisms driving antibiotic resistance in S. typhi. Furthermore, employing computational methodologies, We meticulously assessed the potential of lignans, specifically Schisandrin A, B, and C, as promising Efflux Pump Inhibitors (EPIs) against the identified P-gp homologue in S. typhi. Noteworthy findings revealed robust binding interactions of Schisandrin A and B with the target protein, indicating substantial inhibitory capabilities. In contrast, Schisandrin C exhibited instability, showing varied effectiveness among the evaluated lignans. Pharmacokinetics and toxicity predictions underscored the favourable attributes of Schisandrin A, including prolonged action duration. Furthermore, high systemic stability and demanished toxicity profile of SA and SB present their therapeutic efficacy against MDR. This comprehensive investigation not only elucidates potential therapeutic strategies against MDR strains of S. typhi but also highlights the relevance of computational approaches in identifying and evaluating promising candidates. These findings lay a robust foundation for future empirical studies to address the formidable challenges antibiotic resistance poses in this clinically significant infectious diseases. [ABSTRACT FROM AUTHOR]

Salmonella Paratyphi A, one of the major etiologic agents of enteric fever, has increased in prevalence in recent decades in certain endemic regions in comparison to S. Typhi, the most prevalent cause of enteric fever. Despite this increase, data on the prevalence and molecular epidemiology of S. Paratyphi A remain generally scarce. Here, we analysed the whole genome sequences of 216 S. Paratyphi A isolates originating from Kathmandu, Nepal between 2005 and 2014, of which 200 were from patients with acute enteric fever and 16 from the gallbladder of people with suspected chronic carriage. By exploiting the recently developed genotyping framework for S. Paratyphi A (Paratype), we identified several genotypes circulating in Kathmandu. Notably, we observed an unusual clonal expansion of genotype 2.4.3 over a four-year period that spread geographically and systematically replaced other genotypes. This rapid genotype replacement is hypothesised to have been driven by both reduced susceptibility to fluoroquinolones and genetic changes to virulence factors, such as functional and structural genes encoding the type 3 secretion systems. Finally, we show that person-to-person is likely the most common mode of transmission and chronic carriers seem to play a limited role in maintaining disease circulation. Author summary: Enteric (typhoid) fever is caused by bacteria of Salmonella enterica species, specifically Salmonella Typhi and Salmonella Paratyphi A. While the former is most commonly identified as the causative agent of enteric fever, S. Paratyphi A is increasing in prevalence in many endemic areas like Nepal. However, the understanding of the phylogenetic structure and population dynamics of this organism, as well as transmission patterns, remains incomplete. Here, we provide a detailed phylogenetic analysis of S. Paratyphi A isolated from enteric fever patients in Nepal through whole genome sequence analysis, combined with epidemiological observations, such as water source use, and chronological and location data. We observed an unusual expansion of a genotype (genetic ID) that replaced other genotypes in the area, indicative of changes in circulating population composition. This expansion is hypothesised to have been driven by reduction in antibiotic susceptibility and changes on bacterial structures that are important for pathogenicity. Our data also suggest person-to-person as the most likely mode of transmission for this pathogen. Understanding of S. Paratyphi A population structure, sources of infection, and transmission will help develop policies for enteric fever management, particularly prior to vaccine introduction, as changes in population composition may affect vaccine efficacy. [ABSTRACT FROM AUTHOR]

Many bacterial pathogens, including the human exclusive pathogen Salmonella Typhi, express capsular polysaccharides as a crucial virulence factor. Here, through S. Typhi whole genome sequence analyses and functional studies, we found a list of single point mutations that make S. Typhi hypervirulent. We discovered a single point mutation in the Vi biosynthesis enzymes that control Vi polymerization or acetylation is enough to result in different capsule variants of S. Typhi. All variant strains are pathogenic, but the hyper Vi capsule variants are particularly hypervirulent, as demonstrated by the high morbidity and mortality rates observed in infected mice. The hypo Vi capsule variants have primarily been identified in Africa, whereas the hyper Vi capsule variants are distributed worldwide. Collectively, these studies increase awareness about the existence of different capsule variants of S. Typhi, establish a solid foundation for numerous future studies on S. Typhi capsule variants, and offer valuable insights into strategies to combat capsulated bacteria. Here, Lee and Song describe missense mutations in the viaB locus in clinical isolates of Salmonella Typhi that result in hypo- and hyper-virulent phenotypes due to changes in the capsule. [ABSTRACT FROM AUTHOR]

Background: Enteric fever is caused by Salmonella enterica serovars Typhi (S. Typhi) and Paratyphi A, B, and C. It continues to be a significant cause of morbidity and mortality worldwide. In highly endemic areas, children are disproportionately affected, and antimicrobial resistance reduces therapeutic options. It is estimated that 2–5% of enteric fever patients develop chronic asymptomatic infection. These carriers may act as reservoirs of infection; therefore, the prospective identification and treatment of carriers are critical for long-term disease control. We aimed to find the frequency of Salmonella Typhi carriers in patients undergoing cholecystectomy. We also compared the detection limit of culturing versus qPCR in detecting S. Typhi, performed a geospatial analysis of the carriers identified using this study, and evaluated the accuracy of anti-Vi and anti-YncE in identifying chronic typhoid carriage. Methods: We performed a cross-sectional study in two centers in Pakistan. Gallbladder specimens were subjected to quantitative PCR (qPCR) and serum samples were analyzed for IgG against YncE and Vi by ELISA. We also mapped the residential location of those with a positive qPCR result. Findings: Out of 988 participants, 3.4% had qPCR-positive gallbladder samples (23 S. Typhi and 11 S. Paratyphi). Gallstones were more likely to be qPCR positive than bile and gallbladder tissue. Anti-Vi and YncE were significantly correlated (r = 0.78 p<0.0001) and elevated among carriers as compared to qPCR negative controls, except for anti-Vi response in Paratyphi A. But the discriminatory values of these antigens in identifying carriers from qPCR negative controls were low. Conclusion: The high prevalence of typhoid carriers observed in this study suggests that further studies are required to gain information that will help in controlling future typhoid outbreaks in a superior manner than they are currently being managed. Author summary: Enteric fever, caused by bacteria Salmonella Typhi or Paratyphi, is a serious global illness particularly affecting children in areas with inadequate hygiene and sanitation facilities. It is transmitted through the oral-fecal route. In Pakistan, prevalence of extensively drug resistant S. Typhi resistant strain further complicates its treatment. Some infected individuals develop chronic infections and become carriers of these pathogens. These asymptomatic carriers may potentially spread the disease by shedding the bacteria in urine or stool. To assess the frequency of the carrier state, we examined gallbladder specimens (bile, stones, and tissue) from patients who underwent gallbladder removal surgeries at Aga Khan University and Jinnah Post-graduate Medical Centre. We demonstrated that PCR had a higher sensitivity in detecting Salmonella carriage with a detection limit of 102 CFU/ml and identified 3.4% of typhoid carriers. Additionally, we investigated whether specific antibodies could identify these carriers using various serological tests. The results underscore the need for further research to promptly detect and appropriately treat this disease, thereby enhancing control and preventing future outbreaks. [ABSTRACT FROM AUTHOR]

Background: Typhoid is endemic in many low‐income countries, including in Papua New Guinea. This study aimed to describe the burden and clinical features of typhoid in children in a provincial hospital, to describe environmental conditions that lead to typhoid, and to document the antibiotic sensitivity of Salmonella spp. in the Eastern Highlands Province. Methods: A combined retrospective and prospective study of children admitted to with clinical features of typhoid to the Goroka Hospital throughout 2022. Results: The study included 98 children, of which 54% were female. The median age was 8 (IQR 5–10.6) years. Over 60% of the patients were from Goroka District, the peri‐urban area encompassing the town and surrounds. Ninety‐four percent (92) of the patients used a pit latrine as a toilet and only 28% had access to treated water. Neuropsychiatric symptoms were common (60%), as was leukopenia (48%), thrombocytopenia (52%) and anaemia (42%). Thirty‐seven patients had positive blood cultures for Salmonella typhi; all isolates were sensitive to third‐generation cephalosporins, pefloxacin, ampicillin, trimethoprim and sulfamethoxazole, and only 54% sensitive to chloramphenicol. The median duration of hospitalisation was 6 days (IQR). There were no deaths. Conclusion: Prompt public health actions are needed to reduce the burden of typhoid infection in the Papua New Guinea. The conjugate typhoid vaccine should be considered in the highlands region, where typhoid is most endemic. [ABSTRACT FROM AUTHOR]

Salmonellosis, caused by Salmonella species, is one of the most common foodborne illnesses worldwide with an estimated 93.8 million cases and about 155,00 fatalities. In both industrialized and developing nations, Salmonellosis has been reported to be one of the most prevalent foodborne zoonoses and is linked with arrays of illness syndromes such as acute and chronic enteritis, and septicaemia. The two major and most common Salmonella species implicated in both warm-blooded and cold-blooded animals are Salmonella bongori and Salmonella enterica. To date, more than 2400 S. enterica serovars which affect both humans and animals have been identified. Salmonella is further classified into serotypes based on three primary antigenic determinants: somatic (O), flagella (H), and capsular (K). The capacity of nearly all Salmonella species to infect, multiply, and survive in human host cells with the aid of their pathogenic and virulence arsenals makes them deadly and important public health pathogens. Primarily, food-producing animals such as poultry, swine, cattle, and their products have been identified as important sources of salmonellosis. Additionally, raw fruits and vegetables are among other food types that have been linked to the spread of Salmonella spp. Based on the clinical manifestation of human salmonellosis, Salmonella strains can be categorized as either non-typhoidal Salmonella (NTS) and typhoidal Salmonella. The detection of aseptically collected Salmonella in necropsies, environmental samples, feedstuffs, rectal swabs, and food products serves as the basis for diagnosis. In developing nations, typhoid fever due to Salmonella Typhi typically results in the death of 5%-30% of those affected. The World Health Organization (WHO) calculated that there are between 16 and 17 million typhoid cases worldwide each year, with scaring 600,000 deaths as a result. The contagiousness of a Salmonella outbreak depends on the bacterial strain, serovar, growth environment, and host susceptibility. Risk factors for Salmonella infection include a variety of foods; for example, contaminated chicken, beef, and pork. Globally, there is a growing incidence and emergence of life-threatening clinical cases, especially due to multidrugresistant (MDR) Salmonella spp, including strains exhibiting resistance to important antimicrobials such as betalactams, fluoroquinolones, and third-generation cephalosporins. In extreme cases, especially in situations involving very difficult-to-treat strains, death usually results. The severity of the infections resulting from Salmonella pathogens is dependent on the serovar type, host susceptibility, the type of bacterial strains, and growth environment. This review therefore aims to detail the nomenclature, etiology, history, pathogenesis, reservoir, clinical manifestations, diagnosis, epidemiology, transmission, risk factors, antimicrobial resistance, public health importance, economic impact, treatment, and control of salmonellosis. [ABSTRACT FROM AUTHOR]

The separation of target substances is a significant biological detection procedure, where magnetic microspheres can act as high-performance separation materials. However, challenges are still kept to fulfill all the requirements. A submicron magnetic poly (glycidyl methacrylate) (PGMA) microsphere was synthesized in this investigation by utilizing three distinct techniques: in situ coprecipitation, electrostatic self-assembly, and silica surface coating. The PGMA microspheres were initially produced through a soap-free emulsion polymerization technique, wherein the coagulation process was governed by surface charge density. This factor additionally impacted the size and monodispersity of the microspheres. Then, we discovered that the capping agent sodium citrate (Na3Cit) effectively regulated the superparamagnetism properties of magnetic microspheres; the critical size of the superparamagnetic was 10.9 nm. Furthermore, the concentration of Fe2+ and Fe3+ effectively regulated the saturation magnetization, a property that correlated with the nucleation rate of the Fe3O4 crystal. Additionally, we demonstrated that the pH regulated the electrostatic self-assembly, and it was suggested that positively charged PGMA–NH2 microspheres and negatively charged Fe3O4 nanoparticles be tightly coupled. For application, the PGMA@Fe3O4 microspheres were subsequently coated with SiO2, which had been surface-modified with carboxyl groups. The PGMA@Fe3O4 and carboxyl-modified microspheres exhibited saturated magnetization values of 23.73 and 17.73 emu/g, respectively. These microspheres have been effectively utilized for the extraction of DNA from various sources such as Salmonella typhi, monkeypox virus, and clinical swab samples, suggesting the potential of these microspheres for nucleic acid separation in the biomedical domain. [ABSTRACT FROM AUTHOR]

Objectives: Lichens are complex symbiotic organisms that generate various bioactive compounds with significant therapeutic value. We investigated the chemical composition and bioactivity of the acetone extract of the Algerian lichen Physconia venusta (Ach.) poet. Materials and Methods: Phytochemical screening was performed using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity was assessed against Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhi, Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis using an agar diffusion test with the determination of the minimal inhibition concentration (MIC), while the antioxidant activity was determined using different chemical methods (DPPH, ABTS, CUPRAC, reducing power, superoxide anion scavenging, ß-carotene bleaching, and metal chelate). In addition, cytotoxic activity was tested using Artemia salina (Brine shrimp) bioassay. Results: The studied extract exhibited intense antibacterial activity against E. coli and S. aureus with inhibition diameters of 28 ± 0.01 and 22 ± 0.01 mm, respectively, with a MIC value of 6.25 mg/mL and a selectivity index of 2.8. The obtained extract showed different antioxidant trends depending on the selected assay. GC-MS analysis revealed many secondary metabolites. Conclusion: P. venusta, a type of lichen, is a potential source of bioactive substances that could be used in pharmaceuticals. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is capable of producing biofilms on various surfaces, medical implants and burn wounds which inhibit the action of antimicrobial agents. This study was undertaken for the screening, identification and purification of a natural antimicrobial compound from the hospital waste sites against P. aeruginosa. The partial purification of the antimicrobial agent was performed with ethyl acetate from the culture supernatant of the isolate and further purified by HPLC. For the characterization of the active compound, we have used Fourier Transform Infrared Spectroscopy (FT-IR) and Electrospray Ionization mass spectrometry (ESI-MS) analysis. The purified compound was tested for anti-biofilm activity in vitro against P. aeruginosa and on various surfaces such as plastic, glass, and steel. The potent isolate was confirmed as Bacillus licheniformis strain RG1002. The HPLC purified compound was characterized as lichenysin using FTIR and ESI-MS analysis. This study identifies and characterize the potent antimicrobial agent against other important human pathogens such as Staphylococcus aureus, Salmonella typhi, Shigella flexneri and Escherichia coli. Purified lichenysin showed strong inhibitory effect against P. aeruginosa and other important pathogens and inhibits the biofilm formation of P. aeruginosa in vitro on various types of surfaces. The current study suggests the application of lichenysin as a protective coating on various indwelling medical devices and catheters to prevent the biofilm formation by P. aeruginosa. [ABSTRACT FROM AUTHOR]

Endophytic bacteria reside within the plant cell and are beneficial to it in a number of ways like growth, protection to environmental conditions and sustainability in favor of the hosts. Throughout the ages, Garlic (Allium sativum L.) has legendary therapeutic importance. The important step in endophyte isolation is the removal of plant tissue surface microflora, called as surface sterilization. Endophytes from medicinal plants may mimic the compound produced by the host plant and also plays an important role in production of bioactive compound, so it is necessary to isolate endophytes, not the epiphytic microbes. The present investigation was undertaken with an aim to optimize the sterilization parameters viz: time and concentration of ethanol and sodium hypochlorite for isolation of endophytic bacteria as well as exploring their antibacterial activity from Allium sativum. The results revealed that concentration and exposure time of sterilizing agent caused prominent surface sterilization but have negative effect on isolation of endophytes. Experimental results revealed that 70% ethanol (6 min), 2% sodium hypochlorite (1 min) followed by 70% ethanol (30 sec) is effective for surface sterilization of leaf and 70% ethanol (6 min), 3% sodium hypochlorite (1 min) followed by ethanol (30 sec) for bulb of Allium sativum. A total of 86 bacterial endophytes were recovered and screened for antibacterial activity against Enterococcus faecalis, Bacillus cereus ATCC 11778, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterobacter, Klebsiella pneumoniae, Salmonella typhi and Proteus. Out of 86 bacterial endophytes, only (9%) endophytes were found to be inhibiting one or all test human pathogen. The findings of the present study suggest that use of optimized sterilization conditions are effective for removing surface bacterial strains without affecting endophytes as well as the Allium sativum plant of the Jaunpur district represents an excellent reservoir of endophytic bacteria and novel source of bioactive compounds. On the other hand different concentration and time of their exposure to different parts of plant is required for proper surface sterilization of that part and isolation of endophytes. [ABSTRACT FROM AUTHOR]

Adenostemma lavenia (L.) is one of the medicinal plants on Nias Island that is used to treat many symptoms including cough, fever and diarrhea. Empirical data of this plant suggests that these medicinal benefits can be attributed to its antibacterial and antioxidant properties, as well as the total flavonoids contained within it, but research on this is still limited. Adenostemma lavenia (L.) was extracted with ethanol, while the antibacterial properties were measured using the disc method. Antioxidant testing was conducted with the DPPH (1,1-diphenyl-2-2picrihydrazyl) inhibition method. Total flavonoids were assessed using a modified AlCl3 method with a quercetin standard. Antibacterial test results of Staphylococcus aureus, Klebsiela pneumoniae, Propionibacterium acnes, Escherichia coli, Salmonella typhi, Bacillus cereus and Shigella sonnei with mean inhibition were 8.76 ± 0.44, 8.13 ± 0.72, 8.77 ± 0.45, 6.47 ± 0.54, 7.77 ± 0.60, 7.33 ± 0.44, 12.06 ± 0.60 respectively. IC50 was 59.844 ± 3.36 ppm. Total flavonoids were 13.566 ± 0.021 mcg/g. The results of the antibacterial test of the ethanolic extract of Adenostemma lavenia (L.) were classified as moderate. The antioxidant activity and total flavonoids were in the high category, which can be attributed to the capture of free radicals to overcome disease. [ABSTRACT FROM AUTHOR]

The synthesis of 2-((5-methyl-pyridin-2-yl)amino)acetic acid (MPAA) and its copper complex (Cu-MPAA) has been performed. The new ligand, MPAA, was obtained via a catalyst-free reaction at room temperature by mixing a solution of 2-amino-5-methylpyridine (AMPy) with chloroacetic acid (CA) in a short time. The characterization of MPAA has been carried out using NMR and FTIR spectroscopies, while the complex has been characterized using UV–Vis spectroscopy, AAS, FTIR, molar conductivity, TGA–DSC, and magnetic moments. According to the DFT calculation, Cu(II) forms both coordination and semi-coordination bonds through the carboxylate group of MPAA. Antibacterial activity has been performed using the disk diffusion method against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Staphylococcus epidermidis, and Pseudomonas aeruginosa. The Cu-MPAA complex exhibited the highest activity compared to other tested compounds. Furthermore, molecular docking studies provided additional evidence in favor of these findings. Moreover, through in silico studies, the synthesized complex adhered to acceptable predictive ADMET features and drug-likeness rules. Collectively, we believe that this complex could make a significant contribution to the efficient design of metal-derived agents to treat microbial infections. [ABSTRACT FROM AUTHOR]

Phoenix dactylifera L. and its wastes are known to be high in nutrients that are beneficial to human health. The study aimed to evaluate the antimicrobial, antibiofilm, and antiviral properties of Phoenix dactylifera L. pits extract (PDPE) in vitro. Gas chromatography-mass spectrometry (GC–MS) analysis indicated phenol, 2,5-bis(1,1-dimethyl ethyl), tetradecanoic acid, octaethylene glycol monododecyl ether, á-D-glucopyranosiduronic acid, and heptaethylene glycol monododecyl ether existence. The PDPE influenced pathogenic microorganisms, with inhibition zone diameters (IZDs) ranging from 10.0 to 35.0 mm. Staphylococcus aureus ATCC 5638 had the highest IZD, while Salmonella typhi DSM 17058 and Shigella sonnei DSM 5570 had the lowest. The antifungal effect observed only in spore failure or conidia formation. PDPE showed a 100% antibacterial spectrum against bacteria, with MIC values between 250 and 1000 µg/ml. MIC was only indicated with S. aureus of 500 µg/ml. MBC values ranged from 500 to 1000 g/ml, with MBC values of 500 g/ml for B. cereus, E. faecalis, S. typhi, and S. sonnei. The activity was 66.7% at 500 µg/ml, further concentrations of 125–250 g/ml had no antibacterial effect. PDPE biofilm inhibition % had the highest percentage of inhibition (98.59%) with S. aureus, B. cereus (94.12%), and E. coli (74.46%). With 50% (CC50) viral activity, the highest non-toxic PDPE dose was found to be at 123.0 µg/ml. Key points: • Phoenix dactylifera L. pits extract (PDPE) has varied active compounds with different bioactivities. • Phoenix dactylifera L. pits extract (PDPE) has a bactericidal mode of action for various pathogenic bacteria. • Phoenix dactylifera L. pits extract (PDPE) has cytotoxicity 50% (CC50) value at 123.0 µg/ml with 50% viral activity. [ABSTRACT FROM AUTHOR]

Endophytic fungi produce bioactive metabolites that exhibit antibacterial, antioxidant, and anti-cancer activity. Rui (Harrisonia perforata (Blanco) Merr.) is a traditional medicinal plant proven to be an antibacterial and anticancer. Endophytic fungi live in plant tissues without damaging or producing chemicals that infect the host cell. Endophytes produce the same and similar compound as an original plant. This study aimed to isolate the endophytic fungi from Rui and determine their antibacterial, antioxidant, and cytotoxic activity. 13 fungal isolates were successfully isolated using PDA for seven days at 30°C. Molecular identification using the ITS1 and ITS4 DNA sequences only revealed six species: Diaporthe sp., Phomopsis sp., Aspergillus tubingensis, Aspergillus viridinutans, Pseudofusicoccum sp., and Daldinia eschscholtz. Seven isolates showed antibacterial activity based on plate assay. Aspergillus tubingensis and RA-1 exhibited antibacterial activity against Staphylococcus aureus and Salmonella typhi, with the MIC and MBC starting from 24 to 32 mg/ml. The DPPH assay showed the most increased antioxidant activity in Daldinia eschscholtzii with an IC50 of 98.14±2.39 µg/ml. The Brine Shrimp Lethality Test (BSLT) showed the highest potential cytotoxic activity, as shown by Aspergillus tubingensis and Phomopsis sp. with LC50 of 7.78±7.48 and 30.83±0.39 µg/ml. In conclusion, our study demonstrates that the fungal extract from Rui could be a source of antibacterial, antioxidant, and cytotoxic agents. [ABSTRACT FROM AUTHOR]

Background It has been recently shown that the prevalence of segmental colitis associated with diverticulosis (SCAD) is about 2% of all patients who have colonic diverticulosis. However, sometimes it can be overdiagnosed if only endoscopic criteria are applied. We have recognized endoscopic signs of SCAD (lesions of the interdiverticular mucosa with diverticular and rectal sparing) in patients with a variety of conditions other than SCAD. Method We reviewed clinical, endoscopic and histologic data from selected patients with endoscopically visualized signs of SCAD. Results Five patients with endoscopic signs of SCAD were included in this study. SCAD was excluded by the lack of specific biopsy findings, combined with laboratory exams. Final diagnoses were iatrogenic colitis due to immunotherapy (n=1), eosinophilic colitis (n=1), Salmonella typhi (n=1), undetermined inflammatory bowel disease (n=1), and Crohn’s disease (n=1). Conclusions Lesions of the interdiverticular mucosa with diverticular and rectal sparing are not specific for SCAD, but rather a predictor of disease. In consequence, histology and, if necessary, laboratory analyses are mandatory to support a correct SCAD diagnosis. [ABSTRACT FROM AUTHOR]

Pleopeltis crassinervata is a fern documented in ethnobotanical records for its use in Mexican traditional medicine to treat gastric disorders and mouth ulcers. Consequently, conducting biological and pharmacological assays is crucial to validate the therapeutic efficacy of this plant within the context of traditional medicine. In the present study, we investigated the biological activity of extracts and fractions obtained from P. crassinervata organs against bacteria (Salmonella typhimurium, Salmonella typhi, Staphylococcus aureus, Proteus mirabilis, Shigella flexneri, Bacillus subtilis, Escherichia coli) and Trichomonas vaginalis using in vitro models. The precipitate fraction obtained from the frond methanolic extract showed significant antibacterial activity (minimal inhibitory concentration [MIC] 120 µg/mL) against the Staphylococcus aureus strain and was effective against both Gram-positive and Gram-negative bacteria. The hexane fraction also obtained from frond methanolic extract, showed a trichomonacidal effect with an IC50 of 82.8 μg/mL and a low cytotoxic effect. Hsf6 exhibited the highest activity against T. vaginalis, and the GC-MS analysis revealed that the predominant compound was 16-pregnenolone. The remaining identified compounds were primarily terpene-type compounds. [ABSTRACT FROM AUTHOR]

Salmonella species are associated with bacteraemia, diarrhoea, as well as focal infections. Salmonella Typhi is the most pathogenic species. Salmonella Paratyphi B commonly affects immunocompromised hosts. The present case series showcases six cases of infection caused by typhoidal Salmonellae with unusual clinical scenarios. The first case report explains a case of neonatal meningitis where the causative agent was S. Paratyphi B. A case of lumbar spondylodiscitis is also reported where the aetiology was found to be Salmonella Typhi. Case three reports S. Typhi infection in a patient with Pre-B cell Acute Lymphoblastic Leukemia (ALL). S. Paratyphi B was isolated from a blood culture of a patient on haemodialysis and also from ascitic fluid from a case of Chronic Liver Disease (CLD). S. Typhi was isolated from the pleural fluid of a patient with carcinoma of the prostate. [ABSTRACT FROM AUTHOR]

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The escalating global threat of antimicrobial resistance necessitates prospecting uncharted microbial biodiversity for novel therapeutic leads. This study mines the promising chemical richness of Bacillus licheniformis LHG166, a prolific exopolysaccharide (EPSR2-7.22 g/L). It comprised 5 different monosaccharides with 48.11% uronic acid, 17.40% sulfate groups, and 6.09% N-acetyl glucosamine residues. EPSR2 displayed potent antioxidant activity in DPPH and ABTS+, TAC and FRAP assays. Of all the fungi tested, the yeast Candida albicans displayed the highest susceptibility and antibiofilm inhibition. The fungi Aspergillus niger and Penicillium glabrum showed moderate EPSR2 susceptibility. In contrast, the fungi Mucor circinelloides and Trichoderma harzianum were resistant. Among G+ve tested bacteria, Enterococcus faecalis was the most susceptible, while Salmonella typhi was the most sensitive to G-ve pathogens. Encouragingly, EPSR2 predominantly demonstrated bactericidal effects against both bacterial classes based on MBC/MIC of either 1 or 2 superior Gentamicin. At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 88.30% against B. subtilis, while for G-ve antibiofilm inhibition, At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 96.63% against Escherichia coli, Even at the lowest dose of 25% MBC, EPSR2 reduced biofilm formation by 84.13% in E. coli, 61.46% in B. subtilis. The microbial metabolite EPSR2 from Bacillus licheniformis LHG166 shows promise as an eco-friendly natural antibiotic alternative for treating infections and oxidative stress. [ABSTRACT FROM AUTHOR]

Enteric fever caused by Salmonella enterica Typhi and Salmonella Paratyphi A is an important public health problem, especially in low-income and middle-income countries with limited access to safe water and sanitation. We present results from, to our knowledge, the first ever human study of a bivalent paratyphoid A-typhoid conjugate vaccine (Sii-PTCV). In this double-blind phase 1 study, 60 healthy Indian adults were randomly assigned (1:1) to receive a single intramuscular dose of either Sii-PTCV or typhoid conjugate vaccine (Typbar-TCV). Safety was assessed by observing solicited adverse events for 1 week, unsolicited events for 1 month, and serious adverse events (SAEs) over 6 months. Immunogenicity at 1 month and 6 months was assessed by measuring anti-capsular polysaccharide antigen Vi (anti-Vi) IgG and IgA against Salmonella Typhi and anti-lipopolysaccharide (LPS) IgG against Salmonella Paratyphi A by ELISA, and functional antibodies using serum bactericidal assay (SBA) against Salmonella Paratyphi A. This study is registered with Clinical Trial Registry–India (CTRI/2022/06/043608) and is completed. 60 participants were enrolled. Of these 60 participants, 57 (95%) participants were male and three (5%) participants were female. Solicited adverse events were observed in 27 (90%) of 30 participants who received Sii-PTCV and 26 (87%) of 30 participants who received Typbar-TCV. The most common local solicited event was pain in 27 (90%) participants who received Sii-PTCV and in 23 (77%) participants who received Typbar-TCV. The most common solicited systemic event was myalgia in five (17%) participants who received Sii-PTCV, whereas four (13%) participants who received Typbar-TCV had myalgia and four (13%) had headache. No vaccine-related unsolicited adverse events or SAEs were reported. The seroconversion rates on day 29 were 96·7% (95% CI 82·8–99·9) with Sii-PTCV and 100·0% (88·4–100·0) with Typbar-TCV for anti-Vi IgG; 93·3% (77·9–99·2) with Sii-PTCV and 100·0% (88·4–100·0) with Typbar-TCV for anti-Vi IgA; 100·0% (88·4–100·0) with Sii-PTCV and 3·3% (0·1–17·2) with Typbar-TCV for anti-LPS (paratyphoid); and 93·3% (77·9–99·2) with Sii-PTCV and 0% (0·0–11·6) with Typbar-TCV for SBA titres (paratyphoid). Paratyphoid anti-LPS immune responses were sustained at day 181. Sii-PTCV was safe and immunogenic for both typhoid and paratyphoid antigens indicating its potential for providing comprehensive protection against enteric fever. Serum Institute of India. [ABSTRACT FROM AUTHOR]

Background: Typhoid fever is a common cause of febrile illness in low- and middle-income countries. While multidrug-resistant (MDR) Salmonella Typhi (S. Typhi) has spread globally, fluoroquinolone resistance has mainly affected Asia. Methods: Consecutively, 1038 blood cultures were obtained from patients of all age groups with fever and/or suspicion of serious systemic infection admitted at Mnazi Mmoja Hospital, Zanzibar in 2015–2016. S. Typhi were analyzed with antimicrobial susceptibility testing and with short read (61 strains) and long read (9 strains) whole genome sequencing, including three S. Typhi strains isolated in a pilot study 2012–2013. Results: Sixty-three S. Typhi isolates (98%) were MDR carrying blaTEM-1B, sul1 and sul2, dfrA7 and catA1 genes. Low-level ciprofloxacin resistance was detected in 69% (43/62), with a single gyrase mutation gyrA-D87G in 41 strains, and a single gyrA-S83F mutation in the non-MDR strain. All isolates were susceptible to ceftriaxone and azithromycin. All MDR isolates belonged to genotype 4.3.1 lineage I (4.3.1.1), with the antimicrobial resistance determinants located on a composite transposon integrated into the chromosome. Phylogenetically, the MDR subgroup with ciprofloxacin resistance clusters together with two external isolates. Conclusions: We report a high rate of MDR and low-level ciprofloxacin resistant S. Typhi circulating in Zanzibar, belonging to genotype 4.3.1.1, which is widespread in Southeast Asia and African countries and associated with low-level ciprofloxacin resistance. Few therapeutic options are available for treatment of typhoid fever in the study setting. Surveillance of the prevalence, spread and antimicrobial susceptibility of S. Typhi can guide treatment and control efforts. Author summary: Salmonella Typhi causes typhoid fever. Multi-drug resistant (MDR) S. Typhi is spreading globally. Local and regional surveillance of MDR S. Typhi populations using both blood culture and whole genome sequencing can uncover outbreaks and help mapping the spread of S. Typhi and resistance mechanisms, which, in turn, can guide both control and prevention efforts and clinical management. Data regarding the distribution of MDR S. Typhi genotypes and resistance mechanisms is scarce in Zanzibar, Tanzania, as in many other African countries. In this study we characterize S. Typhi phenotypically and genotypically. This study shows high rate of MDR S. Typhi, hence few therapeutic options are available for treatment of typhoid fever in the study setting. Our findings contribute to the knowledge base on typhoid fever in the region and to guide correct treatment of individual patients and control of the disease. [ABSTRACT FROM AUTHOR]