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Martin LB, Tack B, Marchello CS, Sikorski MJ, Owusu-Dabo E, Nyirenda T, Mogasale V, Crump JA. Vaccine value profile for invasive non-typhoidal Salmonella disease. Vaccine 2024; 42:S101-S124. [PMID: 39003017 DOI: 10.1016/j.vaccine.2024.04.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 04/12/2024] [Accepted: 04/14/2024] [Indexed: 07/15/2024]
Abstract
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.
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Affiliation(s)
| | - Bieke Tack
- Department of Clinical Sciences, Institute of Tropical Medicine Antwerp, Belgium and Department of Microbiology, Immunology and Transplantation, KU Leuven, Belgium.
| | | | - Michael J Sikorski
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | | | | | | | - John A Crump
- Centre for International Health, University of Otago, New Zealand.
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Kim JS, Liu L, Kant S, Orlicky DJ, Uppalapati S, Margolis A, Davenport BJ, Morrison TE, Matsuda J, McClelland M, Jones-Carson J, Vazquez-Torres A. Anaerobic respiration of host-derived methionine sulfoxide protects intracellular Salmonella from the phagocyte NADPH oxidase. Cell Host Microbe 2024; 32:411-424.e10. [PMID: 38307020 DOI: 10.1016/j.chom.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/06/2023] [Accepted: 01/10/2024] [Indexed: 02/04/2024]
Abstract
Intracellular Salmonella experiencing oxidative stress downregulates aerobic respiration. To maintain cellular energetics during periods of oxidative stress, intracellular Salmonella must utilize terminal electron acceptors of lower energetic value than molecular oxygen. We show here that intracellular Salmonella undergoes anaerobic respiration during adaptation to the respiratory burst of the phagocyte NADPH oxidase in macrophages and in mice. Reactive oxygen species generated by phagocytes oxidize methionine, generating methionine sulfoxide. Anaerobic Salmonella uses the molybdenum cofactor-containing DmsABC enzymatic complex to reduce methionine sulfoxide. The enzymatic activity of the methionine sulfoxide reductase DmsABC helps Salmonella maintain an alkaline cytoplasm that supports the synthesis of the antioxidant hydrogen sulfide via cysteine desulfuration while providing a source of methionine and fostering redox balancing by associated dehydrogenases. Our investigations demonstrate that nontyphoidal Salmonella responding to oxidative stress exploits the anaerobic metabolism associated with dmsABC gene products, a pathway that has accrued inactivating mutations in human-adapted typhoidal serovars.
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Affiliation(s)
- Ju-Sim Kim
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Lin Liu
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Sashi Kant
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - David J Orlicky
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Siva Uppalapati
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Alyssa Margolis
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Bennett J Davenport
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Thomas E Morrison
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | | | - Michael McClelland
- University of California Irvine School of Medicine, Department of Microbiology and Molecular Genetics, Irvine, CA, USA
| | - Jessica Jones-Carson
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Andres Vazquez-Torres
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, USA.
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Hajra D, Nair AV, Chakravortty D. Decoding the invasive nature of a tropical pathogen of concern: The invasive non-Typhoidal Salmonella strains causing host-restricted extraintestinal infections worldwide. Microbiol Res 2023; 277:127488. [PMID: 37716125 DOI: 10.1016/j.micres.2023.127488] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/18/2023]
Abstract
Invasive-Non-Typhoidal Salmonella (iNTS) are the major cause of health concern in the low-income, under-developed nations in Africa and Asia that lack proper sanitation facilities. Around 5% of the NTS cases give rise to invasive, extraintestinal diseases leading to focal infections like osteomyelitis, meningitis, osteoarthritis, endocarditis and neonatal sepsis. iNTS serovars like S. Typhimurium, S. Enteritidis, S. Dublin, S. Choleraesuis show a greater propensity to become invasive than others which hints at the genetic basis of their emergence. The major risk factors attributing to the invasive diseases include immune-compromised individuals having co-infection with malaria or HIV, or suffering from malnutrition. The rampant use of antibiotics leading to the emergence of multi-drug resistant strains poses a great challenge in disease management. An extensive understanding of the iNTS pathogenesis and its epidemiology will open up avenues for the development of new vaccination and therapeutic strategies to restrict the spread of this neglected disease.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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Yu JL, Jiang LL, Dong R, Liu SY. Intracranial infection and sepsis in infants caused by Salmonella derby: A case report. World J Clin Cases 2023; 11:6961-6966. [PMID: 37901018 PMCID: PMC10600864 DOI: 10.12998/wjcc.v11.i28.6961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/20/2023] [Accepted: 09/06/2023] [Indexed: 09/25/2023] Open
Abstract
BACKGROUND Salmonella derby (S. derby) is a Gram-negative diplococcus that is common in the digestive tract. Infected patients generally experience symptoms such as fever and diarrhea. Mild cases are mostly self-healing gastroenteritis, and severe cases can cause fatal typhoid fever. Clinical cases are more common in children. The most common form of S. derby infection is self-healing gastroenteritis, in which, fever lasts for about 2 d and diarrhea for < 7 d. S. derby can often cause bacterial conjunctivitis, pneumonia, endocarditis, peritonitis and urethritis. However, intracranial infections in infants caused by S. derby are rare in clinical practice and have not been reported before in China. CASE SUMMARY A 4-mo-old female infant had recurrent fever for 2 wk, with a maximum body temperature of around 39.4°C. Treatment for infectious fever in a local hospital was ineffective, and she was admitted to our hospital. Before admission, there was one sudden convulsion, characterized by unclear consciousness, limb twitching, gaze in both eyes, and slight cyanosis on the face. Cerebrospinal fluid (CSF) culture was positive for Gram-negative bacilli, which conformed to S. derby. After treatment with meropenem and ceftriaxone antibiotics, the patient was discharged home in a clinically stable state after 4 wk of treatment. CONCLUSION We reported a rare case of S. derby cultured in CSF. S. derby enters the CSF through the blood-brain barrier, causing purulent meningitis. If not treated timeously, it can lead to serious, life-threatening infection.
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Affiliation(s)
- Jing-Lu Yu
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, Zhejiang Province, China
| | - Li-Li Jiang
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, Zhejiang Province, China
| | - Rong Dong
- Department of Neonatology, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, Zhejiang Province, China
| | - Si-Yu Liu
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, Zhejiang Province, China
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Clinical profiles and antimicrobial resistance patterns of invasive Salmonella infections in children in China. Eur J Clin Microbiol Infect Dis 2022; 41:1215-1225. [PMID: 36040531 PMCID: PMC9489584 DOI: 10.1007/s10096-022-04476-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 07/18/2022] [Indexed: 11/06/2022]
Abstract
Invasive Salmonella infections result in a significant burden of disease including morbidity, mortality, and financial cost in many countries. Besides typhoid fever, the clinical impact of non-typhoid Salmonella infections is increasingly recognized with the improvement of laboratory detection capacity and techniques. A retrospective multicenter study was conducted to analyze the clinical profiles and antimicrobial resistance patterns of invasive Salmonella infections in hospitalized children in China during 2016–2018. A total of 130 children with invasive Salmonella infections were included with the median age of 12 months (range: 1–144 months). Seventy-nine percent of cases occurred between May and October. Pneumonia was the most common comorbidity in 33 (25.4%) patients. Meningitis and septic arthritis caused by nontyphoidal Salmonella (NTS) infections occurred in 12 (9.2%) patients and 5 (3.8%) patients. Patients < 12 months (OR: 16.04) and with septic shock (OR: 23.4), vomit (OR: 13.33), convulsion (OR: 15.86), C-reactive protein (CRP) ≥ 40 g/L (OR: 5.56), and a higher level of procalcitonin (PCT) (OR: 1.05) on admission were statistically associated to an increased risk of developing meningitis. Compared to 114 patients with NTS infections, 16 patients with typhoid fever presented with higher levels of CRP and PCT (P < 0.05). The rates of resistance to ampicillin, sulfamethoxazole/trimethoprim, ciprofloxacin, and ceftriaxone among Salmonella Typhi and NTS isolates were 50% vs 57.3%, 9.1% vs 24.8%, 0% vs 11.2%, and 0% vs 9.9%, respectively. NTS has been the major cause of invasive Salmonella infections in Chinese children and can result in severe diseases. Antimicrobial resistance among NTS was more common.
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MacLennan CA. The Background, Role and Approach for Development of a Controlled Human Infection Model for Nontyphoidal Salmonella. Curr Top Microbiol Immunol 2021. [PMID: 34958419 DOI: 10.1007/82_2021_246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nontyphoidal Salmonella (NTS) is responsible for a major global burden of disease and economic loss, particularly in low- and middle-income countries. It is designated a priority pathogen by the WHO for vaccine development and, with new impetus from vaccine developers, the establishment of an NTS controlled human infection model (CHIM) is timely and valuable. The broadly dichotomous clinical presentations of diarrhoea and invasive disease, commonly bacteraemia, present significant challenges to the development of an NTS CHIM. Nevertheless, if successful, such a CHIM will be invaluable for understanding the pathogenesis of NTS disease, identifying correlates of protection and advancing candidate vaccines towards licensure. This article describes the background case for a CHIM for NTS, the role of such a CHIM and outlines a potential approach to its development.
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Affiliation(s)
- Calman A MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, UK.
- Bill & Melinda Gates Foundation, 62 Buckingham Gate, London, SW16AJ, UK.
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Ke Y, Lu W, Liu W, Zhu P, Chen Q, Zhu Z. Non-typhoidal Salmonella infections among children in a tertiary hospital in Ningbo, Zhejiang, China, 2012-2019. PLoS Negl Trop Dis 2020; 14:e0008732. [PMID: 33017418 PMCID: PMC7561262 DOI: 10.1371/journal.pntd.0008732] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 10/15/2020] [Accepted: 08/18/2020] [Indexed: 11/23/2022] Open
Abstract
Background Non-typhoidal Salmonella (NTS), a common cause of diarrheal enterocolitis, may also cause severe invasive diseases. Limited information on NTS infections in children is available in China. Methods We performed a retrospective study of children admitted to the Ningbo Women and Children’s Hospital with culture-confirmed NTS infections between January 2012 and December 2019. Clinical and microbiological information were collected. We compared demographic, clinical and antibiotic resistance variables of invasive NTS (iNTS) infections and non-invasive NTS (non-iNTS) infections, and explored associations between hospitalizations for pediatric NTS infections and temperature and rainfall. Results A total of 166 pediatric hospitalizations due to NTS infection were identified during the 8-year study period. Most of the 166 children were <5 years old (93.4%). The primary serotype was Salmonella Typhimurium (62.6%). Of 166 children with NTS infections, 11 had invasive infection. Compared to 155 children with non-iNTS infections, we found that iNTS infections were more likely to occur in infants ≤6 months or children with an underlying medical condition of leukemia at admission, but iNTS infections less often presented with a symptom of diarrhea (P <0.05 in all cases). The resistance rates of non-iNTS isolates to ceftazidime, ceftriaxone, cefepime, and aztreonam were significantly higher than those of iNTS isolates (P <0.05 in all cases). In addition, compared with iNTS isolates, non-iNTS isolates were significantly associated with resistance to ≥4 CLSI (Clinical and Laboratory Standard Institute) classes (P = 0.041, OR: 0.089, 95% CI: 0.009–0.901) and ≥2 first-line treatment agents (P = 0.040, OR: 0.159, 95% CI: 0.028–0.916). On the other hand, we found that seasonal NTS hospitalizations were positively associated with average seasonal temperature (r = 0.961, P = 0.039) and average monthly rainfall (r = 0.921, P <0.001). Conclusion Non-iNTS accounts for the majority of infections in this study; infants ≤6 months and children with underlying medical conditions of leukemia are more likely to have invasive infection. The rates of antibiotic resistance in the iNTS isolates are generally lower than those in the non-iNTS isolates. On the other hand, high temperatures and heavy rainfall are positively associated with NTS hospitalizations among children in Ningbo. Non-typhoidal Salmonella (NTS) infection is a foodborne disease with a global heavy burden. NTS usually causes diarrheal enterocolitis in humans and may also cause severe invasive NTS (iNTS) infections. Antimicrobial agents are not recommended for non-severe NTS diarrhea, but they are recommended for people at risk of severe or invasive infection. However, the recognition of iNTS infection among children is difficult before culture. We studied children who had NTS infections in a tertiary pediatric hospital in Ningbo and found that iNTS infections were more likely to occur in infants ≤6 months or children with an underlying medical condition of leukemia at admission, while diarrhea was more common in children with non-iNTS infections. The high rates of antibiotic resistance among children with NTS in Ningbo calls for continuous NTS surveillance. On the other hand, high temperatures and heavy rainfall were positively associated with NTS hospitalizations among children. These findings may help us to improve measures for the prevention, diagnosis and treatment of NTS infections among children.
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Affiliation(s)
- Yefang Ke
- Department of Clinical Laboratory, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang, China
| | - Wenbo Lu
- Department of Clinical Laboratory, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang, China
| | - Wenyuan Liu
- Department of Clinical Laboratory, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang, China
| | - Pan Zhu
- Neonatal Intensive Care Unit, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang, China
| | - Qunying Chen
- Department of Clinical Laboratory, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang, China
| | - Zhe Zhu
- Department of Blood Transfusion, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, Zhejiang, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, Zhejiang, China
- * E-mail:
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Still WL, Tapia MD, Tennant SM, Sylla M, Touré A, Badji H, Keita AM, Sow SO, Levine MM, Kotloff KL. Surveillance for Invasive Salmonella Disease in Bamako, Mali, From 2002 to 2018. Clin Infect Dis 2020; 71:S130-S140. [PMID: 32725229 PMCID: PMC7388721 DOI: 10.1093/cid/ciaa482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Salmonella enterica bloodstream infections are an important cause of childhood morbidity and mortality, including in Mali. We report 17 years of surveillance for nontyphoidal and typhoidal S. enterica infections among inpatients and outpatients at l'Hôpital Gabriel Touré, the main source of pediatric tertiary care in Bamako, Mali. METHODS Between June 2002 and December 2018, a blood culture was collected from 54 748 children aged ≤15 years with fever and/or suspected invasive bacterial infection who provided consent (38 152 inpatients, 16 596 outpatients). Bacterial pathogens were identified using standard microbiological techniques and serovars of S. enterica were determined by PCR and/or agglutination with antisera. RESULTS Nontyphoidal Salmonella (NTS) was identified in 671 enrolled inpatients (1.8% of all enrolled inpatients, 13.8% of enrolled inpatients with a positive culture). S. Enteritidis, the most common NTS serovar, accounted for 38.5% of all NTS isolates (n = 258), followed by S. Typhimurium (31.7%, n = 213). The median (SD) age of children with a culture positive for NTS was 1.8 (3) years. Overall case fatality was 20.9%. An additional 138 inpatients (0.4%) had a positive culture for typhoidal Salmonella. NTS was identified in 11 outpatients (0.07%), while typhoidal Salmonella was found in 49 outpatients (0.3%). The annual incidence of invasive NTS disease decreased over the study period, but case fatality remained high. CONCLUSIONS Although incidence decreased, NTS remained a major cause of invasive bacterial infection and mortality among hospitalized children in Bamako, while typhoidal Salmonella was uncommon. Because 87% of NTS belonged to only 4 serovars, a multivalent vaccine may be an effective strategy to reduce the burden and mortality of invasive NTS.
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Affiliation(s)
- William L Still
- Department of Epidemiology and Public Health, University of Maryland Graduate School, Baltimore, Maryland, USA
| | - Milagritos D Tapia
- Department of Pediatrics and Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sharon M Tennant
- Department of Pediatrics and Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mamadou Sylla
- Centre Pour le Développement des Vaccins–Mali, Bamako, Mali
| | - Aliou Touré
- Centre Pour le Développement des Vaccins–Mali, Bamako, Mali
| | - Henry Badji
- Centre Pour le Développement des Vaccins–Mali, Bamako, Mali
| | | | - Samba O Sow
- Centre Pour le Développement des Vaccins–Mali, Bamako, Mali
| | - Myron M Levine
- Centre Pour le Développement des Vaccins–Mali, Bamako, Mali
| | - Karen L Kotloff
- Department of Pediatrics and Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Correspondence: K. L. Kotloff, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 West Baltimore Street, Room 480, Baltimore, MD 21201–1509 ()
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Park S, Jung B, Kim E, Hong ST, Yoon H, Hahn TW. Salmonella Typhimurium Lacking YjeK as a Candidate Live Attenuated Vaccine Against Invasive Salmonella Infection. Front Immunol 2020; 11:1277. [PMID: 32655567 PMCID: PMC7324483 DOI: 10.3389/fimmu.2020.01277] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 05/20/2020] [Indexed: 12/23/2022] Open
Abstract
Non-typhoidal Salmonella (NTS) causes gastrointestinal infection, which is commonly self-limiting in healthy humans but may lead to invasive infection at extraintestinal sites, leading to bacteremia and focal systemic infections in the immunocompromised. However, a prophylactic vaccine against invasive NTS has not yet been developed. In this work, we explored the potential of a ΔyjeK mutant strain as a live attenuated vaccine against invasive NTS infection. YjeK in combination with YjeA is required for the post-translational modification of elongation factor P (EF-P), which is critical for bacterial protein synthesis. Therefore, malfunction of YjeK and YjeA-mediated EF-P activation might extensively influence protein expression during Salmonella infection. Salmonella lacking YjeK showed substantial alterations in bacterial motility, antibiotics resistance, and virulence. Interestingly, deletion of the yjeK gene increased the expression levels of Salmonella pathogenicity island (SPI)-1 genes but decreased the transcription levels of SPI-2 genes, thereby influencing bacterial invasion and survival abilities in contact with host cells. In a mouse model, the ΔyjeK mutant strain alleviated the levels of splenomegaly and bacterial burdens in the spleen and liver in comparison with the wild-type strain. However, mice immunized with the ΔyjeK mutant displayed increased Th1- and Th2-mediated immune responses at 28 days post-infection, promoting cytokines and antibodies production. Notably, the Th2-associated antibody response was highly induced by administration of the ΔyjeK mutant strain. Consequently, vaccination with the ΔyjeK mutant strain protected 100% of the mice against challenge with lethal invasive Salmonella and significantly relieved bacterial burdens in the organs. Collectively, these results suggest that the ΔyjeK mutant strain can be exploited as a promising live attenuated NTS vaccine.
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Affiliation(s)
- Soyeon Park
- Department of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon, South Korea
| | - Bogyo Jung
- Department of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon, South Korea
| | - Eunsuk Kim
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Seong-Tshool Hong
- Department of Biomedical Sciences and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, South Korea
| | - Hyunjin Yoon
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Tae-Wook Hahn
- Department of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon, South Korea
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Tack B, Phoba MF, Barbé B, Kalonji LM, Hardy L, Van Puyvelde S, Ingelbeen B, Falay D, Ngonda D, van der Sande MAB, Deborggraeve S, Jacobs J, Lunguya O. Non-typhoidal Salmonella bloodstream infections in Kisantu, DR Congo: Emergence of O5-negative Salmonella Typhimurium and extensive drug resistance. PLoS Negl Trop Dis 2020; 14:e0008121. [PMID: 32240161 PMCID: PMC7156106 DOI: 10.1371/journal.pntd.0008121] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 04/14/2020] [Accepted: 02/07/2020] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Non-typhoidal Salmonella (NTS) are a major cause of bloodstream infection (BSI) in sub-Saharan Africa. This study aimed to assess its longitudinal evolution as cause of BSI, its serotype distribution and its antibiotic resistance pattern in Kisantu, DR Congo. METHODS As part of a national surveillance network, blood cultures were sampled in patients with suspected BSI admitted to Kisantu referral hospital from 2015-2017. Blood cultures were worked-up according to international standards. Results were compared to similar data from 2007 onwards. RESULTS In 2015-2017, NTS (n = 896) represented the primary cause of BSI. NTS were isolated from 7.6% of 11,764 suspected and 65.4% of 1371 confirmed BSI. In children <5 years, NTS accounted for 9.6% of suspected BSI. These data were in line with data from previous surveillance periods, except for the proportion of confirmed BSI, which was lower in previous surveillance periods. Salmonella Typhimurium accounted for 63.1% of NTS BSI and Salmonella Enteritidis for 36.4%. Of all Salmonella Typhimurium, 36.9% did not express the O5-antigen (i.e. variant Copenhagen). O5-negative Salmonella Typhimurium were rare before 2013, but increased gradually from then onwards. Multidrug resistance was observed in 87.4% of 864 NTS isolates, decreased ciprofloxacin susceptibility in 7.3%, ceftriaxone resistance in 15.7% and azithromycin resistance in 14.9%. A total of 14.2% of NTS isolates, that were all Salmonella Typhimurium, were multidrug resistant and ceftriaxone and azithromycin co-resistant. These Salmonella isolates were called extensively drug resistant. Compared to previous surveillance periods, proportions of NTS isolates with resistance to ceftriaxone and azithromycin and decreased ciprofloxacin susceptibility increased. CONCLUSION As in previous surveillance periods, NTS ranked first as the cause of BSI in children. The emergence of O5-negative Salmonella Typhimurium needs to be considered in the light of vaccine development. The high proportions of antibiotic resistance are worrisome.
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Affiliation(s)
- Bieke Tack
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KU Leuven, Belgium
- * E-mail:
| | - Marie-France Phoba
- Department of Microbiology, National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo
- Department of Microbiology, University Teaching Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Barbara Barbé
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lisette M. Kalonji
- Department of Microbiology, National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo
- Department of Microbiology, University Teaching Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Liselotte Hardy
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sandra Van Puyvelde
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, Universiteit Antwerpen, Antwerp, Belgium
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Brecht Ingelbeen
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Dadi Falay
- Department of Pediatrics, University Hospital of Kisangani, Kisangani, Democratic Republic of the Congo
| | - Dauly Ngonda
- Department of Pediatrics, University Hospital of Kisangani, Kisangani, Democratic Republic of the Congo
| | - Marianne A. B. van der Sande
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Global Health Centre, Julius Center for Health Sciences and Primary Care, University Medical Centrum Utrecht, Utrecht University, Utrecht, Netherlands
| | - Stijn Deborggraeve
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KU Leuven, Belgium
| | - Octavie Lunguya
- Department of Microbiology, National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo
- Department of Microbiology, University Teaching Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
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11
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Kern WV, Rieg S. Burden of bacterial bloodstream infection-a brief update on epidemiology and significance of multidrug-resistant pathogens. Clin Microbiol Infect 2019; 26:151-157. [PMID: 31712069 DOI: 10.1016/j.cmi.2019.10.031] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Bloodstream infections comprise a wide variety of pathogens and clinical syndromes with considerable overlap with similar syndromes of non-bacteraemic infections and diverse risk factors, therapeutic implications and outcomes. Yet, this heterogeneous 'entity' has the advantage to be pathogen-defined compared with the broad and even more heterogeneous entity 'sepsis', and so has become helpful for clinicians and epidemiologists for research and surveillance purposes. The increasing availability of population-based and large multicentre well-defined cohort studies should allow us to assess with much confidence and in detail its burden, the significance of antimicrobial resistance, and areas of uncertainty regarding further epidemiological evolution and optimized treatment regimens. AIM To review key aspects of bloodstream infection epidemiology and burden, and summarize recent news and questions concerning critical developments. SOURCES Peer-reviewed articles based on the search terms 'bloodstream infection' and 'bacteremia' combined with the terms 'epidemiology' and 'burden'. The emphasis was on new information from studies in adult patients and on the added burden due to pathogen resistance to first- and second-line antimicrobial agents. CONTENT Topics covered include recent developments in the epidemiology of bloodstream infection due to key pathogens and published information about the relevance of resistance for patient outcomes. IMPLICATIONS Despite the availability of population-based studies and an increasing number of large well-defined multicentre cohort studies, more surveillance and systematic data on bloodstream infection epidemiology at regional level and in resource-limited settings may be needed to better design new methods for prevention and define the need for and further develop optimized therapeutic strategies.
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Affiliation(s)
- W V Kern
- Division of Infectious Diseases, Department of Medicine II, Albert-Ludwigs-University Faculty of Medicine and Medical Centre, Freiburg, Germany; ESCMID Study Group on Bloodstream Infection, Endocarditis and Sepsis, Basel, Switzerland.
| | - S Rieg
- Division of Infectious Diseases, Department of Medicine II, Albert-Ludwigs-University Faculty of Medicine and Medical Centre, Freiburg, Germany
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12
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Ondari EM, Klemm EJ, Msefula CL, El Ghany MA, Heath JN, Pickard DJ, Barquist L, Dougan G, Kingsley RA, MacLennan CA. Rapid transcriptional responses to serum exposure are associated with sensitivity and resistance to antibody-mediated complement killing in invasive Salmonella Typhimurium ST313. Wellcome Open Res 2019; 4:74. [PMID: 31231691 PMCID: PMC6560496 DOI: 10.12688/wellcomeopenres.15059.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2019] [Indexed: 11/20/2022] Open
Abstract
Background:
Salmonella Typhimurium ST313 exhibits signatures of adaptation to invasive human infection, including higher resistance to humoral immune responses than gastrointestinal isolates. Full resistance to antibody-mediated complement killing (serum resistance) among nontyphoidal
Salmonellae is uncommon, but selection of highly resistant strains could compromise vaccine-induced antibody immunity. Here, we address the hypothesis that serum resistance is due to a distinct genotype or transcriptome response in
S. Typhimurium ST313. Methods: Six
S. Typhimurium ST313 bloodstream isolates, three of which were antibody resistant, were studied. Genomic content (single nucleotide polymorphisms and larger chromosomal modifications) of the strains was determined by Illumina and PACBIO sequencing, and functionally characterized using RNA-seq, transposon directed insertion site sequencing (TraDIS), targeted gene deletion and transfer of selected point mutations in an attempt to identify features associated with serum resistance.
Results: Sequence polymorphisms in genes from strains with atypical serum susceptibility when transferred from strains that were highly resistant or susceptible to a strain that exhibited intermediate susceptibility did not significantly alter serum killing phenotype. No large chromosomal modifications typified serum resistance or susceptibility. Genes required for resistance to serum identified by TraDIS and RNA-seq included those involved in exopolysaccharide synthesis, iron scavenging and metabolism. Most of the down-regulated genes were associated with membrane proteins. Resistant and susceptible strains had distinct transcriptional responses to serum, particularly related to genes responsible for polysaccharide biosynthesis. There was higher upregulation of
wca locus genes, involved in the biosynthesis of colanic acid exopolysaccharide, in susceptible strains and increased expression of
fepE, a regulator of very long-chain lipopolysaccharide in resistant strains. Conclusion: Clinical isolates of
S. Typhimurium ST313 exhibit distinct antibody susceptibility phenotypes that may be associated with changes in gene expression on exposure to serum.
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Affiliation(s)
- Edna M Ondari
- Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Novartis Vaccines Institute for Global Health, Siena, Italy.,Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Chisomo L Msefula
- Wellcome Trust Sanger Institute, Hinxton, UK.,Malawi-Liverpool-Wellcome Trust Clinical Research Institute, Blantyre, Malawi.,Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Moataz Abd El Ghany
- Wellcome Trust Sanger Institute, Hinxton, UK.,The Westmead Institute for Medical Research and Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, Australia.,King Abdullah University of Science and Technology , Thuwal, Saudi Arabia
| | - Jennifer N Heath
- Institute of Immunology and Immuotherapy, University of Birmingham, Birmingham, UK
| | | | - Lars Barquist
- Wellcome Trust Sanger Institute, Hinxton, UK.,Helmholtz Institute for RNA-based Infection Research , Würzburg, Germany.,Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Hinxton, UK.,Department of Medicine, University of Cambridge Addenbrooke's Hospital Cambridge, Cambridge, UK
| | | | - Calman A MacLennan
- Institute of Immunology and Immuotherapy, University of Birmingham, Birmingham, UK.,Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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13
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Mohan A, Munusamy C, Tan YC, Muthuvelu S, Hashim R, Chien SL, Wong MK, Khairuddin NA, Podin Y, Lau PST, Ng DCE, Ooi MH. Invasive Salmonella infections among children in Bintulu, Sarawak, Malaysian Borneo: a 6-year retrospective review. BMC Infect Dis 2019; 19:330. [PMID: 30999894 PMCID: PMC6471830 DOI: 10.1186/s12879-019-3963-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 04/08/2019] [Indexed: 11/17/2022] Open
Abstract
Background Invasive Salmonella infections result in significant morbidity and mortality in developing countries. In Asia, typhoid and paratyphoid fever are reported to be the major invasive Salmonella infections, while invasive non-typhoidal Salmonella (iNTS) infections are believed to be uncommon. Data from Sarawak, in Malaysian Borneo, are limited. Methods A retrospective study identifying all children aged < 15 years with invasive Salmonella infections from 2011 to 2016 was conducted in Bintulu Hospital in Sarawak. Population incidences, clinical and bacterial characteristics were examined. Results Forty-four patients were identified during the 6-year study period: 43 had iNTS infection and 1 had typhoid fever. The average annual iNTS incidence was 32.4 per 100,000 children aged < 5 years. None of the children had malaria or HIV infection, and only 7% were severely malnourished. Salmonella Enteritidis and Salmonella Java were the commonest NTS serovars identified. Pneumonia was the most common manifestation of iNTS disease, present in 20 (47%) children. Other manifestations included gastroenteritis, fever without a source, septic arthritis and meningitis. Salmonella Enteritidis was identified in 76% of those with pneumonia, significantly more frequently than in children with other manifestations. Over 25% of children with iNTS developed severe disease and nearly 10% suffered long term morbidity or mortality. While 78% of Salmonella Java isolates were multi-drug resistant, nearly all other isolates were susceptible to most antimicrobials, including ampicillin. Conclusions Bintulu Division in Sarawak observed a very high incidence of childhood iNTS infections. Enteric fever was uncommon. The epidemiology of invasive Salmonella infections in Malaysian Borneo differs considerably from that of neighbouring countries in Asia.
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Affiliation(s)
- Anand Mohan
- Department of Paediatrics, Bintulu Hospital, Bintulu, Sarawak, Malaysia. .,Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia.
| | - Chandran Munusamy
- Department of Paediatrics, Bintulu Hospital, Bintulu, Sarawak, Malaysia
| | - Yee-Chin Tan
- Department of Paediatrics, Bintulu Hospital, Bintulu, Sarawak, Malaysia
| | - Sobana Muthuvelu
- Department of Paediatrics, Bintulu Hospital, Bintulu, Sarawak, Malaysia
| | - Rohaidah Hashim
- Bacteriology Unit, Infectious Disease Research Centre, Institute for Medical Research, Kuala Lumpur, Malaysia
| | - Su-Lin Chien
- Department of Pathology, Bintulu Hospital, Bintulu, Sarawak, Malaysia
| | - Ming-Kui Wong
- Department of Pathology, Bintulu Hospital, Bintulu, Sarawak, Malaysia
| | | | - Yuwana Podin
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia
| | | | - David Chun-Ern Ng
- Department of Paediatrics, Bintulu Hospital, Bintulu, Sarawak, Malaysia.,Department of Paediatrics, Hospital Tuanku Ja'afar, Seremban, Negeri Sembilan, Malaysia
| | - Mong-How Ooi
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia.,Department of Paediatrics, Sarawak General Hospital, Kuching, Sarawak, Malaysia
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14
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Abstract
Nontyphoidal salmonellae (NTS) are a major cause of invasive (iNTS) disease in sub-Saharan Africa, manifesting as bacteremia and meningitis. Available epidemiological data indicate that iNTS disease is endemic in much of the region. Antimicrobial resistance is common and case fatality rates are high. There are well-characterized clinical associations with iNTS disease, including young age, HIV infection, malaria, malnutrition, anemia, and sickle cell disease. However, the clinical presentation of iNTS disease is often with fever alone, so clinical diagnosis is impossible without blood culture confirmation. No vaccine is currently available, making this a priority area for global health research. Over the past ten years, it has emerged that iNTS disease in Africa is caused by distinct pathovars of Salmonella Typhimurium, belonging to sequence type ST313, and Salmonella Enteritidis. These are characterized by genome degradation and appear to be adapting to an invasive lifestyle. Investigation of rare patients with primary immunodeficiencies has suggested a key role for interferon gamma-mediated immunity in host defense against NTS. This concept has been supported by recent population-based host genetic studies in African children. In contrast, immunoepidemiological studies from Africa indicate an important role for antibody for protective immunity, supporting the development of antibody-inducing vaccines against iNTS disease. With candidate O-antigen-based vaccines due to enter clinical trials in the near future, research efforts should focus on understanding the relative contributions of antibody and cell-mediated immunity to protection against iNTS disease in humans.
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Affiliation(s)
| | - Calman A MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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15
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Comparative immunogenicity and efficacy of equivalent outer membrane vesicle and glycoconjugate vaccines against nontyphoidal Salmonella. Proc Natl Acad Sci U S A 2018; 115:10428-10433. [PMID: 30262653 PMCID: PMC6187145 DOI: 10.1073/pnas.1807655115] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nontyphoidal Salmonellae cause a devastating burden of invasive disease in sub-Saharan Africa with high levels of antimicrobial resistance. Vaccination has potential for a major global health impact, but no licensed vaccine is available. The lack of commercial incentive makes simple, affordable technologies the preferred route for vaccine development. Here we compare equivalent Generalized Modules for Membrane Antigens (GMMA) outer membrane vesicles and O-antigen-CRM197 glycoconjugates to deliver lipopolysaccharide O-antigen in bivalent Salmonella Typhimurium and Enteritidis vaccines. Salmonella strains were chosen and tolR deleted to induce GMMA production. O-antigens were extracted from wild-type bacteria and conjugated to CRM197 Purified GMMA and glycoconjugates were characterized and tested in mice for immunogenicity and ability to reduce Salmonella infection. GMMA and glycoconjugate O-antigen had similar structural characteristics, O-acetylation, and glucosylation levels. Immunization with GMMA induced higher anti-O-antigen IgG than glycoconjugate administered without Alhydrogel adjuvant. With Alhydrogel, antibody levels were similar. GMMA induced a diverse antibody isotype profile with greater serum bactericidal activity than glycoconjugate, which induced almost exclusively IgG1. Immunization reduced bacterial colonization of mice subsequently infected with SalmonellaS Typhimurium numbers were lower in tissues of mice vaccinated with GMMA compared with glycoconjugate. S. Enteritidis burden in the tissues was similar in mice immunized with either vaccine. With favorable immunogenicity, low cost, and ability to induce functional antibodies and reduce bacterial burden, GMMA offer a promising strategy for the development of a nontyphoidal Salmonella vaccine compared with established glycoconjugates. GMMA technology is potentially attractive for development of vaccines against other bacteria of global health significance.
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