Anthony Marius Smith

• PhD
• Researcher at National Institute for Communicable Diseases

The role of genomics in public health surveillance has been accentuated by its crucial contributions during the COVID-19 pandemic, demonstrating its potential in addressing global disease outbreaks. While Africa has made strides in expanding multi-pathogen genomic surveillance, the integration into foodborne disease (FBD) surveillance remains nasce...

Objectives Vibrio cholerae remains a significant public health threat in Africa, with antimicrobial resistance (AMR) complicating treatment. This study leverages whole-genome sequencing (WGS) of V. cholerae isolates from Côte d’Ivoire, Ghana, Zambia and South Africa to assess genomic diversity, AMR profiles, and virulence, demonstrating the utility...

Purpose: Antimicrobial resistance (AMR) is important in the pathogenesis and spread of Clostridioides difficile infection (CDI). However, very little is known about the association of AMR and C. difficile in South Africa. The present study aimed to investigate the phenotypic and genotypic antimicrobial profiles of clinical C. difficile isolates. Me...

Health authorities were notified of a suspected outbreak of foodborne disease in a hospital in South Africa, where staff and patients reported acute onset of abdominal cramps, diarrhoea, fever and rigours after eating a chicken pasta meal. The aim of this report is to discuss the use of whole genome sequencing (WGS) analysis of bacterial isolates t...

Diarrhoeagenic Escherichia coli (DEC) persistently challenges public health in Africa, contributing substantially to the diarrhoeal disease burden. This systematic review and meta-analysis illuminate the distribution and antimicrobial resistance (AMR) patterns of DEC pathotypes across the continent. The review selectively focused on pathotype-speci...

Health authorities were notified of a suspected outbreak of foodborne disease in a hospital in South Africa, where staff and patients reported acute onset of abdominal cramps, diarrhoea, fever, and rigors after eating a chicken pasta meal. The aim of this report is to discuss the use of whole-genome sequencing (WGS) analysis of bacterial isolates t...

Background Typhoid fever results from systemic infection with Salmonella enterica serovar Typhi (Typhi) and causes 10 million illnesses annually. Disease control relies on prevention (water, sanitation, and hygiene interventions or vaccination) and effective antimicrobial treatment. Antimicrobial resistant (AMR) Typhi lineages have emerged and beco...

Our 24-month study used metagenomics to investigate antimicrobial resistance (AMR) abundance in raw sewage from wastewater treatment works (WWTWs) in two municipalities in Gauteng Province, South Africa. At the AMR class level, data showed similar trends at all WWTWs, showing that aminoglycoside, beta-lactam, sulfonamide and tetracycline resistance...

Introduction Pseudomonas aeruginosa AUST‐03 (ST242) has been reported to cause epidemics in people with CF (pwCF) from Australia and has been associated with multidrug resistance and increased morbidity and mortality. Here, we report an epidemic P. aeruginosa (AUST‐03) strain in South African pwCF detected at a public hospital and characterize the...

Escherichia coli is an indicator micro-organism in One Health antibiotic resistance surveillance programs. The purpose of the study was to describe and compare E. coli isolates obtained from pigs and human contacts from a commercial farm in South Africa using conventional methods and whole-genome sequencing (WGS). Porcine E. coli isolates were prop...

Escherichia coli is an indicator microorganism in One Health antibiotic resistance surveillance programmes. The purpose of the study was to describe and compare E. coli isolates obtained from pigs and human contacts from a commercial farm in South Africa using conventional methods and whole genome sequencing (WGS). Porcine E. coli isolates were pro...

Introduction Health authorities were notified of a suspected outbreak of foodborne disease in a hospital in South Africa. Staff and patients reported acute onset of abdominal cramps, diarrhoea, fever and rigors after eating a chicken pasta meal. Aim To report on the use whole-genome sequencing (WGS) analysis of bacterial isolates to support an epid...

Salmonella enterica serovar Infantis presents an ever-increasing threat to public health because of its spread throughout many countries and association with high levels of antimicrobial resistance (AMR). We analyzed whole-genome sequences of 5,284 Salmonella Infantis strains from 74 countries, isolated during 1989-2020 from a wide variety of human...

Background In South Africa, the annual incidence of enteric fever averaged 0.1 per 100 000 persons between 2003 and 2018. During 2021 an increase in the number of enteric fever cases was observed. An outbreak investigation was conducted to determine the magnitude and source of the outbreak. Methods We performed a cross-sectional descriptive study....

Shigellosis, a leading cause of diarrhoeal mortality and morbidity globally, predominantly affects children under five years of age living in low- and middle-income countries. While whole genome sequence analysis (WGSA) has been effectively used to further our understanding of shigellosis epidemiology, antimicrobial resistance, and transmission, it...

Background We describe the genotypic characteristics and antimicrobial resistance (AMR) determinants of Salmonella enterica serovar Isangi (Salmonella Isangi) clinical isolates in South Africa from 2020 through 2021. Methods During the years 2020 to 2021, the Centre for Enteric Diseases of the National Institute for Communicable Diseases, a nation...

Objectives Antimicrobial-resistant Neisseria gonorrhoeae (NG) is a concern. Little is known about antimicrobial susceptibility profiles and associated genetic resistance mechanisms of NG in Madagascar. We report susceptibility data of NG isolates obtained by the medical laboratory (CBC) of the Institut Pasteur de Madagascar, Antananarivo, Madagasca...

Introduction: Pseudomonas aeruginosa AUST-03 (ST242) has been reported to cause epidemics in cystic fibrosis (CF) patients from Tasmania and Australia and has been associated with multidrug resistance and increased morbidity and mortality. Here, we report epidemic P. aeruginosa (AUST-03) strains in South African CF patients at a public academic hos...

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a major cause of bloodstream infection among hospitalized patients in low- and middle-income countries (LMICs). CRAB infections can be difficult to treat and are devastating in neonates (~30% mortality). CRAB outbreaks are hypothesized to arise from reservoirs in the hos...

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...

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...

Salmonell a Infantis presents an ever-increasing threat to public health due to its spread throughout many countries and association with high levels of antimicrobial resistance (AMR). Whole genome sequences of 5,284 S . Infantis strains from 74 countries, isolated between 1989 and 2020 from a wide variety of sources including humans, animals, and...

Carbapenem-resistant Acinetobacter baumannii (CRAb) has emerged as a major and often fatal cause of bloodstream infections among hospitalized patients in low- and middle-income countries (LMICs). CRAb outbreaks are hypothesized to arise from reservoirs in the hospital environment, but outbreak investigations in LMICs are seldom able to incorporate...

Since February 2022, Malawi has experienced a cholera outbreak of >54,000 cases. We investigated 6 cases in South Africa and found that isolates linked to the outbreak were Vibrio cholerae O1 serotype Ogawa from seventh pandemic El Tor sublineage AFR15, indicating a new introduction of cholera into Africa from south Asia.

The global response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic demonstrated the value of timely and open sharing of genomic data with standardized metadata to facilitate monitoring of the emergence and spread of new variants. Here, we make the case for the value of Salmonella Typhi (S. Typhi) genomic data and demon...

The National Institute for Communicable Diseases in South Africa participates in national laboratory-based surveillance for human isolates of Salmonella species. Laboratory analysis includes whole-genome sequencing (WGS) of isolates. We report on WGS-based surveillance of Salmonella enterica serovar Typhi (Salmonella Typhi) in South Africa from 202...

Background: We describe the genotypic characteristics and antimicrobial resistance (AMR) determinants of Salmonella enterica serovar Isangi (Salmonella Isangi) clinical isolates in South Africa from 2020 through 2021. Methods: During the years 2020 to 2021, the Centre for Enteric Diseases of the National Institute for Communicable Diseases, a natio...

Shigellosis, a leading cause of diarrhoeal mortality and morbidity globally, predominantly affects children under five years of age living in low- and middle-income countries. While whole genome sequence analysis (WGSA) has been effectively used to further our understanding of shigellosis epidemiology, antimicrobial resistance, and transmission, it...

Salmonella Enteritidis is the most reported non-typhoidal Salmonella serovar and is implicated in both gastroenteritis and invasive non-typhoidal disease. Whole-genome sequence comparison of Salmonella Enteritidis isolates from across the world identified four definitive clades: Outlier, Global Epidemic, East African and West African. Three of thes...

The antimicrobial resistance of Neisseria gonorrhoea to all classes of current available antibiotics is a global concern. National surveillance programmes monitoring the susceptibility profiles of Neisseria gonorrhoeae hardly exist in resource constraint settings. Therefore, little is known about the antimicrobial susceptibility profile and associa...

Objectives: We investigated whether patients with cryptococcal meningitis (CM) or fungaemia detected through South Africa's laboratory cryptococcal antigen (CrAg) screening programme had better outcomes than those presenting directly to hospital. Methods: We compared 14-day in-hospital case-fatality ratios (CFR) of HIV-seropositive individuals w...

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 twenty-one years since the publication of the first Typhi genome, represents the largest Typhi genome seque...

Salmonella enterica serovar Enteritidis is one of the most commonly reported serovars of nontyphoidal Salmonella causing human disease and is responsible for both gastroenteritis and invasive nontyphoidal Salmonella (iNTS) disease worldwide. Whole-genome sequence (WGS) comparison of Salmonella Enteritidis isolates from across the world has identifi...

Salmonella Enteritidis is one of the most commonly reported serovars of non-typhoidal Salmonella causing human disease and is responsible for both gastroenteritis and invasive non-typhoidal Salmonella (iNTS) disease worldwide. Whole-genome sequence (WGS) comparison of Salmonella Enteritidis isolates from across the world have identified three disti...

Salmonella Infantis is presenting an increasing risk to public health. Of particular concern are the reports of pESI, a multidrug resistance (MDR) encoding megaplasmid, in isolates from multiple countries, but little is known about its presence or diversity in South Africa. Whole genome sequences of 387 S . Infantis isolates from South Africa (2004...

In South Africa, there is a shortage of epidemiologic data on Shiga toxin-producing Escherichia coli (STEC) in the beef production chain. This study was conducted to characterize STEC isolates originating from three studies conducted in a cattle feedlot, beef abattoirs and retail outlets in Gauteng province, South Africa. Polymerase chain reaction...

Objectives : This study investigated antimicrobial susceptibility and genomic profiling of S. enterica isolated from bloodstream infections at a tertiary referral hospital in Lusaka, Zambia, 2018-2019. Method : This was a prospective hospital-based study involving routine blood culture samples submitted to the microbiology laboratory at the Univer...

PulseNet International (PNI) is a global network of 88 countries who work together through their regional and national public health laboratories to track foodborne disease around the world. The vision of PNI is to implement globally standardized surveillance using whole genome sequencing (WGS) for real-time identification and subtyping of foodborn...

We have developed an efficient and inexpensive pipeline for streamlining large-scale collection and genome sequencing of bacterial isolates. Evaluation of this method involved a worldwide research collaboration focused on the model organism Salmonella enterica , the 10KSG consortium. Following the optimization of a logistics pipeline that involved...

Background In sub-Saharan Africa, acute respiratory infections (ARI), acute gastrointestinal infections (GI) and acute febrile disease of unknown cause (AFDUC) have a large disease burden, especially among children, while respective aetiologies often remain unresolved. The need for robust infectious disease surveillance to detect emerging pathogens...

We describe the molecular epidemiology of cholera in South Africa during 2018–2020. Vibrio cholerae O1 sequence type (ST) 75 recently emerged and became more prevalent than the V. cholerae O1 biotype El Tor pandemic clone. ST75 isolates were found across large spatial and temporal distances, suggesting local ST75 spread.

Background: Typhoid fever remains a public health concern in South Africa, where the risk of transmission is high because of poor access to safe water and sanitation. This study describes the investigation of typhoid fever outbreak in Limpopo province. Methodology: Following notification of laboratory-confirmed cases, a descriptive study was con...

Salmonella enterica serotype Enteritidis ( Salmonella Enteritidis) is a major cause of foodborne disease outbreaks worldwide. In 2018, two concurrent outbreaks of Salmonella Enteritidis gastroenteritis in one district of South Africa were investigated. We describe the use of whole-genome sequencing (WGS) analysis of bacterial isolates to assist wit...

Background: An outbreak of listeriosis was identified in South Africa in 2017. The source was unknown. Methods: We conducted epidemiologic, trace-back, and environmental investigations and used whole-genome sequencing to type Listeria monocytogenes isolates. A case was defined as laboratory-confirmed L. monocytogenes infection during the period fro...

Introduction: In 2009 and 2010, more than 6,000 cholera cases were recorded during these outbreaks with more than 80% of cases recorded in Lusaka province. After a five-year break, in 2016 an outbreak occurred in Lusaka, causing more than 1,000 cases of cholera. This study will strengthen the epidemiological information on the changing characteris...

Background: In light of rampant childhood diarrhoea, this study investigated bacterial pathogens from human and non-human sources in an urban informal settlement. Meat from informal abattoirs (n = 85), river water (n = 64), and diarrheic stool (n = 66) were collected between September 2015 and May 2016. A duplex real-time PCR, gel-based PCR, and C...

Introduction: Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens that may cause diarrhoeal outbreaks and occasionally are associated with haemolytic-uraemic syndrome (HUS). We report on STEC O26:H11 associated with a cluster of four HUS cases in South Africa in 2017. Methodology: All case-patients were female and aged 5 years...

Background: Typhoid fever remains a major public health problem in Zimbabwe with recurrent outbreaks reported since 2009. To provide guidance on appropriate treatment choice in order to minimise the morbidity and mortality of typhoid fever and prevent large scale outbreaks, we investigated the antimicrobial susceptibility patterns, prevalence of S...

In South Africa, a progressive increase in listeriosis cases was noted from mid-June 2017, heralding what was to become the world's largest listeriosis outbreak. A total of 1060 cases were reported for the period January 1, 2017 to July 17, 2018. We describe laboratory activities, experiences, and results of whole-genome sequencing (WGS) analysis o...

Background: In sub-Saharan Africa, molecular epidemiological investigation of outbreaks caused by antimicrobial-resistant enteric bacterial pathogens have mostly been described for Salmonella species, Vibrio cholerae, Shigella species and Escherichia coli. For these organisms, I reviewed all publications describing the use of molecular subtyping me...

Introduction: Guillain-Barré Syndrome (GBS) is an autoimmune disease characterized by acute or subacute symmetrical ascending motor weakness, areflexia, and mild-to-moderate sensory abnormalities. Campylobacter jejuni is reported to be the most common bacterium associated with GBS cases. Despite the eradication of polio, the number of reported GBS...

Typhoid fever is notifiable in South Africa but clinical notification is notoriously poor. South Africa has an estimated annual incidence rate of 0.1 cases per 100,000 population of culture-confirmed typhoid fever, decreased from 17 cases per 100,000 population in the 1980s. This work was undertaken to identify the reasons for this decrease and ide...

We report whole-genome sequences for 10 Listeria monocytogenes sequence type 6 isolates associated with a large listeriosis outbreak in South Africa, which occurred over the period of 2017 to 2018. The possibility of listeriosis spreading beyond South Africa’s borders as a result of exported contaminated food products prompted us to make the genome...

Background Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) has become a significant pathogen in South Africa, and the need for improved molecular surveillance of this pathogen has become important. Over the years, multi-locus variable-number tandem-repeats analysis (MLVA) has become a valuable molecular subtyping technique for Salm...

Background Workers in clinical microbiology laboratories are exposed to a variety of pathogenic microorganisms. Salmonella species is among the most commonly reported bacterial causes of laboratory-acquired infections. We report on three cases of laboratory-acquired Salmonella enterica serotype Typhi (Salmonella Typhi) infection which occurred over...

Shiga toxin-producing Escherichia coli (STEC) strains are primarily food-borne pathogens that may cause diarrheal outbreaks and are associated with severe complications, specifically hemolytic-uremic syndrome (HUS). We report here ge-nome sequence data for STEC O26:H11, which is associated with a cluster of cases of HUS, a rarely described syndrome...

Purpose: Molecular epidemiological investigations of the highly clonal Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) are important in outbreak detection and in tracking disease transmission. In this study, we developed and evaluated a multiple-locus variable-number tandem-repeats (VNTR) analysis (MLVA) assay for characterization...

PulseNet International is a global network dedicated to laboratory-based surveillance for food-borne diseases. The network comprises the national and regional laboratory networks of Africa, Asia Pacific, Canada, Europe, Latin America and the Caribbean, the Middle East, and the United States. The PulseNet International vision is the standardised use...

Objective: Shigella sonnei is a globally-important diarrhoeal pathogen tracked through the surveillance network PulseNet Latin America and Caribbean (PNLA&C), which participates in PulseNet International. PNLA&C laboratories use common molecular techniques to track pathogens causing foodborne illness. We aimed to demonstrate the possibility and ad...

Introduction: Shiga toxin-producing Escherichia coli (STEC) is an emerging infectious pathogen which could lead to haemolytic uremic syndrome. Even though previous studies have compared the performance of CHROMagarTMSTEC to real-time polymerase chain reaction (PCR) in Europe, no study has been done to assess its performance on African isolates. Obj...

The population of Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever, exhibits limited DNA sequence variation, which complicates efforts to rationally discriminate individual isolates. Here we utilize data from whole-genome sequences (WGS) of nearly 2,000 isolates sourced from over 60 countries to generate a robust g...

Background Typhoid fever remains an important disease in Africa, associated with outbreaks and the emerging multidrug resistant Salmonella enterica serotype Typhi (Salmonella Typhi) haplotype, H58. This study describes the incidence of, and factors associated with mortality due to, typhoid fever in South Africa, where HIV prevalence is high. Metho...

Background: The burden of typhoid in sub-Saharan African (SSA) countries has been difficult to estimate, in part, due to suboptimal laboratory diagnostics. However, surveillance blood cultures at two sites in Nigeria have identified typhoid associated with Salmonella enterica serovar Typhi (S. Typhi) as an important cause of bacteremia in children...

An epidemiological paradox surrounds Salmonella enterica serovar Enteritidis. In high-income settings, it has been responsible for an epidemic of poultry-associated, self-limiting enterocolitis, whereas in sub-Saharan Africa it is a major cause of invasive nontyphoidal Salmonella disease, associated with high case fatality. By whole-genome sequence...

Listeria monocytogenes is a Gram-positive bacterium with a ubiquitous presence in the environment. There is growing concern about the increasing prevalence of L. monocytogenes associated with food-borne outbreaks. Here we report genome sequences for a cluster of human isolates of L. monocytogenes identified in South Africa in 2015.

We used standardized methodologies to characterize Vibrio cholerae O1 isolates from Guinea, Democratic Republic of the Congo (DRC), Togo, Côte d'Ivoire and Mozambique. We investigated 257 human isolates collected in 2010 to 2013. DRC isolates serotyped O1 Inaba, while isolates from other countries serotyped O1 Ogawa. All isolates were biotype El To...