This scoping review evaluates the role of vector-associated dissemination in contaminating the Philippine food supply chain with antimicrobial-resistant (AMR) Salmonella, an emerging infectious disease threat, using a One Health perspective to map the mechanisms through which insects and rodents bridge environmental reservoirs to human food systems. This scoping review was conducted and reported in accordance with the PRISMA-ScR guidelines. From 1969 records identified through systematic database searches, 52 studies met the inclusion criteria. These comprised 21 primary Philippine studies, 28 non-Philippine studies (including ASEAN-based historical baseline reports), and 3 policy/gray literature studies, prioritized to reflect tropical ecological and agricultural settings. Results suggest that intensive swine and poultry farming may contribute to the emergence of multidrug resistance (MDR) linked to genes such as blaTEM and qnr. Evidence suggests that Salmonella persists in environmental matrices, such as manure and irrigation water, and that synanthropic vectors, including Rattus rattus and various fly species, potentially serve as biological and mechanical bridges in transmission. Clinical data reveal an alarming trend toward invasive non-typhoidal salmonellosis (iNTS) showing reduced susceptibility to cephalosporins and fluoroquinolones. Despite these findings, major evidence gaps remain, particularly regarding the prevalence of vector-borne Salmonella in pre-harvest produce. Consequently, mitigation requires a One Health framework that integrates non-antibiotic interventions, pest management to disrupt transmission pathways, and rapid diagnostic tools, such as loop-mediated isothermal amplification (LAMP), to enhance market surveillance.
Antimicrobial resistance (AMR) represents a critical global public health threat, complicating the treatment of common infections and imposing substantial economic burdens. The widespread misuse and overuse of antimicrobial agents in human medicine, animal agriculture, and environmental settings have accelerated the emergence and spread of resistant bacteria, compromising decades of progress in infectious disease control and food safety [
1,
2]. The evolution of
Salmonella spp. exemplifies this crisis as a primary driver of foodborne illness that is increasingly associated with multidrug resistance (MDR), particularly in low- and middle-income countries (LMICs) such as the Philippines. The Philippine food supply chain, comprising small-scale farms, informal markets, and densely populated urban–rural interfaces, offers numerous opportunities for the introduction and amplification of pathogens such as
Salmonella. Local research has documented extensive contamination in retail products sold in wet markets and slaughterhouses, where a high proportion of isolates exhibit MDR profiles and harbor critical resistance determinants, including extended-spectrum β-lactamases (ESBLs) [
3,
4].
Addressing this escalating prevalence within Philippine food systems requires a One Health framework to map the dynamics within the interconnected human, animal, and environmental sectors. Resistance emerges from the combined effects of selective pressures across animal husbandry, clinical settings, and environmental reservoirs, thereby allowing
Salmonella to persist and circulate. Multiple studies have already documented the presence of these pathogens carrying clinically relevant resistance markers in swine and poultry, including
bla and
qnr genes and p
ESI plasmids, across slaughterhouses and retail markets [
5,
6].
Synanthropic vectors, including flies and rodents, may act as biological and mechanical bridges, transporting pathogens from manure and contaminated surfaces to animal feed, carcasses, and food-handling sites [
7]. While genomic surveillance of human clinical isolates in the Philippines reveals a high prevalence of fluoroquinolone resistance [
8,
9], the specific contribution of vector-mediated dissemination remains underexplored. By extending pathogen reach beyond direct or animal-environmental contact, these vectors underscore the need to integrate insect and rodent management into food safety and AMR mitigation strategies, setting the stage for a One Health Approach to map the complex ecological carriers of
Salmonella dissemination in the Philippine food system.
Considering these interlinked dynamics, this review synthesizes evidence on vector-associated contamination of the Philippine food supply chain by AMR-Salmonella. Specifically, this review aims to address four key research questions: (1) What are the mechanisms and impacts of vector-mediated AMR-Salmonella contamination? (2) What is the prevalence and persistence of Salmonella within animal-environmental reservoirs? (3) Which vector species and food system nodes are most susceptible to Salmonella dissemination? (4) What strategies and policies currently exist to control vector-mediated AMR Salmonella transmission? Overall, this review synthesizes existing evidence and proposes a One Health framework to mitigate vector-mediated transmission of AMR-Salmonella across animal, environmental, and human health systems.
This entry is adapted from the peer-reviewed paper 10.3390/encyclopedia6070141
