2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea

Evaluation of Single and Multi-Strain Probiotics with Gentamicin Against E. coli O157:H7: Insights from In Vitro and In Vivo Studies

The emergence of antibiotic-resistant food-borne pathogens, especially Escherichia coli O157:H7, highlights the urgent need for innovative treatment strategies, particularly in light of rising resistances and the ongoing controversy surrounding antibiotic use in response to E. coli O157:H7 infections. To address this issue, we explored the potential of single- and multi-strain probiotics, both independently and in combination with gentamicin, through a series of in vitro and in vivo experiments. In vitro, gentamicin alone produced a mean inhibition zone of 12.9 ± 2.27 mm against E. coli O157:H7. The combination of gentamicin with single-strain probiotics (P1) increased the inhibition zone to 16.5 ± 2.24 mm (p < 0.05), while the combination with multi-strain probiotics (P2) resulted in the largest inhibition zone of 19 ± 2.8 mm (p < 0.05). In vivo, mice infected with E. coli O157:H7 and treated with P2, gentamicin (G), or their combination (G+P2), achieved 100% survival, no pathological symptoms, and full weight recovery within seven days. Conversely, mice treated with P1 or G+P1 exhibited lower survival rates (71.4% and 85%, respectively) and slower weight recovery. Hematological parameters improved across all groups, but kidney function analysis showed significantly higher serum creatinine levels in the P1, G, G+P1, and G+P2 groups compared to the P2 group (P1: 0.63 ± 0.15 mg/dL; G: 0.34 ± 0.09 mg/dL; G+P1: 0.53 ± 0.19 mg/dL; G+P2: 0.5 ± 0.23 mg/dL vs. P2: 0.24 ± 0.2 mg/dL). Histological analysis showed better intestinal and kidney tissue recovery in the P2 group, while the P1 and G+P1 groups exhibited abnormal ileal structures and severe cortical bleeding. These findings highlight the promise of multi-strain probiotics, alone or in conjunction with antibiotics, as a therapeutic strategy for E. coli O157:H7 infections. However, the nephrotoxicity associated with gentamicin co-administration remains a limitation, warranting further studies to optimize this approach.

Practical Recommendations in the Treatment of Acute and Chronic Life-Threatening Infectious Diseases in Patients with Acute Hepatic Porphyria

BACKGROUND

Acute hepatic porphyrias (AHPs) represent inherited metabolic disorders of the heme biosynthesis pathway, leading to neurological and systemic impairment. Despite the presence of well-recognized chronic symptoms and signs, acute neurological, both neuromuscular and central neurological complications pose a significant challenge in clinical practice, with a potential risk of greater severity and mortality during acute decompensation episodes of AHPs. Care related to the prescription of medications, considering the risk of porphyrinogenicity, is a major and recurring concern in the acute and chronic management of AHP patients. Infectious clinical complications are significant issues in both outpatient and hospital settings for patients with AHPs. It is crucial to identify therapeutic regimens with the best safety and efficacy profiles for treating such infectious complications in AHP patients. The scarcity of structured knowledge available in guidelines and recommendations often leads to the use of therapeutic options with higher potential risks in treating patients with AHPs.

OBJECTIVES

This review article aims to provide practical recommendations for managing the most significant infectious complications in clinical practice, with a focus on their impact on the clinical care of patients with AHPs.

A One Health approach for the genomic characterization of antibiotic-resistant Campylobacter isolates using Nanopore whole-genome sequencing

In response to the growing threat posed by the spread of antimicrobial resistance in zoonotic Campylobacter, a One Health approach was used to examine the genomic diversity, phylogenomic relationships, and the distribution of genetic determinants of resistance (GDR) in C. jejuni and C. coli isolates from humans, animals (ruminants, swine, and chickens), and avian food products collected during a regionally (Basque Country, Spain) and temporally (mostly 2021-2022) restricted sampling. Eighty-three C. jejuni and seventy-one C. coli isolates, most exhibiting resistance to ciprofloxacin and/or erythromycin, were whole-genome sequenced using Oxford Nanopore Technologies long-fragment sequencing (ONT). Multilocus sequence typing (MLST) analysis identified a high genomic diversity among isolates. Phylogenomic analysis showed that clustering based on the core genome was aligned with MLST profiles, regardless of the sample source. In contrast, accessory genome content sometimes discriminated isolates within the same STs and occasionally differentiated isolates from different sources. The majority of the identified GDRs were present in isolates from different sources, and a good correlation was observed between GDR distribution and phenotypic susceptibility profiles (based on minimum inhibitory concentrations interpreted according to the EUCAST epidemiological cutoff values). Genotypic resistance profiles were independent of genotypes, indicating no apparent association between resistance and phylogenetic origin. This study demonstrates that ONT sequencing is a powerful tool for molecular surveillance of bacterial pathogens in the One Health framework.

Characterization of Shigella flexneri serotype 6 strains from geographically diverse low- and middle-income countries

Shigella flexneri serotype 6 (Sf6) is one of the most common serotypes recovered from surveillance studies of moderate to severe diarrhea. Despite the clinical significance of Sf6, this serotype is understudied. In this work, we have performed both serotype-specific genomic and phenotypic comparisons of Sf6 isolates to one another and non-S. flexneri serotypes. Comparative genomic analyses identified significant nucleotide homology between Sf6 strains (n = 325), despite a broad range of collection timeframes and geographic locations. We identified Sf6 specific factors, including a potential novel Shigella virulence factor (type II secretion system). Additionally, we identified established Shigella virulence genes (ospG) and metabolic genes (rutABCDEFGR) that were absent in Sf6 strains while present in the majority of 728 non-Sf6 strains. Complete sequencing of 11 clinical Sf6 strains, demonstrated that the Sf6 virulence plasmid (pINV) is ~38 kb smaller than the average non-Sf6 pINV (~228 kb). Comparisons of S. flexneri species level antibiotic susceptibility highlighted that clinical Sf6 isolates from Africa in the Global Enteric Multicenter Study (GEMS) and Vaccine Impact on Diarrhea in Africa (VIDA) study demonstrated geographic, serotype-specific susceptibility pattern. Phenotypic analyses of Sf6 identified reduced intracellular invasion and cytokine induction from HT-29 cells, as well as reduced Ipa protein effector secretion, compared with S. flexneri serotype 2a strain 2457T. Together these data highlight conserved and unique serotype-specific genotypic and phenotypic features for Sf6. This level of conservation has not been noted for other S. flexneri serotypes and is promising for vaccine and diagnostic assays to provide global Sf6-specific coverage.IMPORTANCEShigellosis is an ongoing global public health crisis with >270 million annual episodes among all age groups; however, the greatest disease burden is among children in low- and middle-income countries (LMIC). The lack of a licensed Shigella vaccine and the observed rise in antimicrobial-resistant Shigella spp. highlights the urgency for effective preventative and interventional strategies. The inclusion of S. flexneri serotype 6 (Sf6) is a necessary component of a multivalent vaccine strategies based on its clinical and epidemiological importance. Given the genomic diversity of Sf6 compared with other S. flexneri serotypes and Sf6 unique O-antigen core structure, serotype-specific characterization of Sf6 is a critical step to inform Shigella-directed vaccine and alternative therapeutic designs. Herein, we identified conserved genomic content among a large collection of temporally and geographically diverse Sf6 clinical isolates and characterized genotypic and phenotypic properties that separate Sf6 from non-Sf6 S. flexneri serotypes.

Etiological, Clinical, and Epidemiological Characteristics of Acute Viral Gastroenteritis in an Adult Population in a Tertiary Level Hospital in Spain

INTRODUCTION

Acute gastroenteritis (AGE) represents a significant global health burden, with enteric viruses being a leading cause of gastroenteritis worldwide. Despite advances in diagnosis and treatment, there are limited data on adults seeking care due to AGE of viral etiology. This study aimed to describe the etiological, clinical, and epidemiological characteristics of viral AGE in adult patients presenting for medical consultation in a tertiary hospital over a 2-year period.

METHODS

A retrospective cross-sectional study was conducted, with 8886 stool samples from 8356 adult patients presenting acute diarrhea between January 2021 and December 2022. A molecular real-time RT-PCR panel was used to screen for common bacterial, parasitic, and viral pathogens. Clinical and demographic data were collected, and statistical analysis was performed to evaluate possible associations.

RESULTS

Enteric viruses constituted 10.3% (307 cases) of all AGE of known etiology, with norovirus being the predominant pathogen (196, 63.8%), followed by rotavirus (82, 26.7%) and adenovirus (29, 9.4%). The different viruses showed a distinct seasonal predominance. Coinfection with other microorganisms was common. Most cases exhibited a self-limiting course. Mortality and hospitalization rates were high in patients with higher comorbidity indices, mainly in individuals with immunosuppression.

CONCLUSIONS

Viruses are an important cause of acute gastroenteritis in adults presenting for medical consultation. The new multiplex molecular tests with high sensitivity and specificity allow early differential diagnosis in AGE. It is therefore necessary to identify which special populations particularly with higher comorbidity indices, would benefit from the implementation of these techniques, to guide decision-making related to appropriate treatments and avoid unnecessary interventions.

Variation in plasmid conjugation among nontyphoidal Salmonella enterica serovars

Conjugation is a complex phenomenon involving multiple plasmid, bacterial, and environmental factors. Here we describe an IncI1 plasmid encoding multidrug antibiotic resistance to aminoglycosides, sulfonamides, and third-generation cephalosporins. This plasmid is widespread geographically among animal, human, and environmental sectors. We present data on the transmissibility of this plasmid from Salmonella enterica ser. Kentucky into 40 strains of S. enterica (10 strains each from serovars Enteritidis, Heidelberg, Infantis, and Typhimurium). Thirty seven out of 40 strains were able to take up the plasmid. Rates of conjugation were variable between strains ranging from 10-8 to 10-4. Overall, serovars Enteritidis and Typhimurium demonstrated the highest rates of conjugation, followed by Heidelberg, and then Infantis. No relationships were observed between the recipient cell surface and rate of conjugation. Recipient cell numbers correlated positively with conjugation rate and strains with high conjugation rates had marginally but significantly higher growth parameters compared to strains that took up the plasmid at lower frequencies. Environmental conditions known to impact cell growth, such as temperature, nutrient availability, and the presence of antibiotics, had a modulating effect on conjugation. Collectively, these results will further understanding of plasmid transmission dynamics in Salmonella, which is a critical first step towards the development of mitigation strategies.

Campylobacter jejuni/coli Infection: Is It Still a Concern?

Campylobacteriosis is a leading cause of infectious diarrhea and foodborne illness worldwide. Campylobacter infection is primarily transmitted through the consumption of contaminated food, especially uncooked meat, or untreated water; contact with infected animals or contaminated environments; poultry is the primary reservoir and source of human transmission. The clinical spectrum of Campylobacter jejuni/coli infection can be classified into two distinct categories: gastrointestinal and extraintestinal manifestations. Late complications are reactive arthritis, Guillain-Barré syndrome, and Miller Fisher syndrome. In the pediatric population, the 0-4 age group has the highest incidence of campylobacteriosis. Regarding the use of specific antimicrobial therapy, international guidelines agree in recommending it for severe intestinal infections. Host factors, including malnutrition, immunodeficiency, and malignancy, can also influence the decision to treat. The Centers for Disease Control and Prevention (CDC) has identified antibiotic resistance in Campylobacter as a 'significant public health threat' due to increasing resistance to FQs or macrolides. Although numerous vaccines have been proposed in recent years to reduce the intestinal colonization of poultry, none have shown sufficient efficacy to provide a definitive solution.

Analysis of Efflux Pump Contributions and Plasmid-Mediated Genetic Determinants in Ciprofloxacin-Resistant Salmonella

This study aimed to explore the interactions among genetic determinants influencing ciprofloxacin resistance in Salmonella. Treatment with PAβN, an efflux pump inhibitor, resulted in a 4-32-fold reduction in the minimum inhibitory concentration (MIC) across all 18 ciprofloxacin-resistant Salmonella isolates. Notably, isolates without point mutations reverted from resistance to sensitivity. The efflux pump played a crucial role in resistance development, particularly in serovar Enteritidis, where PAβN treatment caused a more significant MIC reduction (16-32-fold) in five strains carrying the GyrA (Asp87Tyr) mutation, which initially exhibited high MICs (8 μg/mL). Several resistance genes were identified on transferable plasmids: oqxAB and aac(6')-Ib-cr were associated with IncF plasmids in S. Enteritidis, IncA/C plasmids in S. Typhimurium, and IncHI2 plasmids in S. Virchow. Additionally, qnrS1 and/or qepA were carried by IncA/C plasmids in S. Thompson. Whole-genome sequencing revealed the presence of an oqxAB module integrated into the chromosomal DNA of S. Derby. Although the MICs of ciprofloxacin in transconjugants and transformants remained low (1-4 μg/mL), they exceeded the clinical breakpoint for susceptibility. These findings highlight the synergistic impact of efflux pumps and plasmid-mediated resistance mechanisms, contributing to the increasing prevalence of ciprofloxacin resistance and posing a significant threat to food safety.

Gut-derived PPAR-γ signaling and risk of bacterial enteric infection: insight from thiazolidinedione users in a US population-based study

Background and Aims

The ongoing antimicrobial resistant crisis heralds the need for new therapeutics against enteric infection. In mouse models, colon epithelial peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling limits oxygen and nitrate luminal bioavailability, thereby preventing bacterial pathogen colonization. However, whether this mechanism operates similarly in humans remains uncertain.

Methods

To investigate, we used the cloud-based TriNetX Analytics Platform which aggregates health records from 117 million patients across 66 US healthcare organizations, to assess the risk of bacterial enteric infection among diabetic patients prescribed thiazolidinediones, a class of PPAR-γ agonists, to other anti-diabetes medications.

Results

Among 85,117 thiazolidinedione users, we observed a 22-49% lower risk of bacterial enteric infections compared to users of other anti-diabetes medications. This reduction in risk was consistent across high-risk individuals, regardless of sex or age. Similar results were replicated in high-risk patients when thiazolidinedione users were directly compared to those on DPP-4 inhibitors.

Conclusion

These findings support the potential protective role of PPAR-γ signaling against bacterial enteric infection and call for further clinical investigation.

Use of stool molecular panel in hospitalized patients with diarrhea. Experience in a tertiary care center

Infectious diarrhea is a common health issue that affects a large number of individuals each year. It causes significant morbidity and mortality, greatly impacting healthcare system costs. Rapid detection of the causative organism and timely treatment alters the management and outcome of the condition. Molecular panels in stool allow to analyze a wide range of pathogens quickly and easily. For this study, a cross-sectional cohort analysis with a retrospective analysis of adult patients hospitalized with diarrhea and negative conventional stool bacteriological studies was conducted. Data obtained from the use of molecular panels in stool and the role of endoscopy in the diagnostic pathway were analyzed. A positivity rate of 52% (n=41) out of a total of 79 samples was reported. The test contributed to a change in therapeutic approach in 58% (n=46) of the patients. Among the patients with a negative molecular panel, 39.5% underwent further evaluation with colonoscopy involving biopsies, resulting in a diagnostic yield of 87%. Based on these results, we can conclude that molecular techniques contribute to the diagnosis and change in therapeutic approach in hospitalized patients with diarrhea.

Campylobacter jejuni from no antibiotics ever (NAE) broilers: prevalence, antibiotic resistance, and virulence genes analysis

Campylobacter jejuni (C. jejuni) is a leading foodborne illness causing bacteria, and poultry is a major reservoir of this pathogen. With the recent increase in broiler production under the "no antibiotics ever" (NAE) system, this study aimed to assess the prevalence, antibiotic resistance, and virulence characteristics of C. jejuni isolated from NAE raised broilers. A total of 270 cloacal swabs were collected from the live-hang areas of 3 commercial processing plants over 9 wk. Each processing plant was visited 3 times at a 1-wk interval, and 30 samples were collected per visit. Among the total 270 cloacal swab samples, C. jejuni was isolated from 44 (16.3%) samples . Of these isolates, 65.9% possessed toxin-producing genes cdtA, cdtB, and cdtC, and invasion gene ciaB. The prevalence of antibioitc resistance genes aph (3')-IIIa, erm(B) were 59.1%, and 50%, respectively. Nine (20.45%) C. jejuni isolates were identified as multidrug resistant (MDR), and 18 (40.9%) isolates showed resistance to at least 1 tested antibiotic. The highest resistance was observed against tetracycline (29.5%), followed by nalidixic acid (25%), whereas 22.7% of isolates were resistant to 2 clinically important antibiotics, azithromycin and ciprofloxacin. These results suggest that there ishigh prevalence level of multi-drug resistant C. jejuni with toxin producing virulence genes in the NAE-raised broilers sampled in this study, indicating the potential for serious human illnesses if transmitted through the food chain.

Etiologies of Bloody Diarrhea in Children Presenting With Acute Gastroenteritis to US Emergency Departments

We used molecular testing to examine the causes of bloody diarrhea in a multicenter study of pediatric gastroenteritis. Pathogens typically associated with bloody diarrhea were detected in less than half of cases, and inappropriate antibiotic use was common, supporting the use of stool testing in patients with bloody diarrhea.

Assessing Community Pharmacists' Management of Acute Diarrhea in Saudi Arabia: A Simulated Patient Study

INTRODUCTION

Antimicrobial resistance poses a significant threat to global health, and community pharmacists are positioned to play a crucial role in mitigating this issue. The present study aimed to evaluate the extent of compliance among community pharmacists in Saudi Arabia with relevant regulations and clinical guidelines in the management of suspected infectious diarrhea.

METHOD

This cross-sectional study employed simulated patients presenting with diarrhea to assess the management practices within 200 community pharmacies in two major cities across Saudi Arabia. Trained pharmacy students presented pharmacists with three case scenarios involving adult patients with diarrhea. Statistical analysis included descriptive statistics and chi-square tests to examine the relationships between pharmacist characteristics and practice categories.

RESULTS

The findings of this study indicate that the performance of community pharmacists in managing diarrhea is suboptimal. Notably, less adequate practice emerged as the predominant outcome at 63% (n = 126). Only 14% (n = 28) of pharmacists demonstrated adequate practice, while 23% (n = 46) exhibited poor investigative practice. Metronidazole dispensing increased across scenarios, from 16.92% (n = 11) in Scenario 1 to 30.3% (n = 20) in Scenario 3. Most pharmacists inquired about the patient's age (72%; n = 144); however, only a limited number probed for symptoms of dehydration (5.5%, n = 11) and medication history (3%, n = 6). A significant association was found between geographical location and practice performance (p = 0.015).

CONCLUSIONS

This study reveals significant deficiencies in the management of infection-related diarrhea, underscoring the urgent need for enhanced training and regulatory measures within community pharmacy settings in Saudi Arabia to improve patient care and effectively address antimicrobial resistance (AMR).

In Silico Analysis of Probiotic Bacteria Changes Across COVID-19 Severity Stages

The gut microbiota plays a crucial role in modulating the immune response during COVID-19, with several studies reporting significant alterations in specific bacterial genera, including Akkermansia, Bacteroides, Bifidobacterium, Faecalibacterium, Lactobacillus, Oscillospira, and Ruminococcus. These genera are symbionts of the gut microbiota and contribute to host health. However, comparing results across studies is challenging due to differences in analysis methods and reference databases. We screened 16S rRNA raw datasets available in public databases on COVID-19, focusing on the V3-V4 region of the bacterial genome. In total, seven studies were included. All samples underwent the same bioinformatics pipeline, evaluating the differential abundance of these seven bacterial genera at each level of severity. The reanalysis identified significant changes in differential abundance. Bifidobacterium emerged as a potential biomarker of disease severity and a therapeutic target. Bacteroides presented a complex pattern, possibly related to disease-associated inflammation or opportunistic pathogen growth. Lactobacillus showed significant changes in abundance across the COVID-19 stages. On the other hand, Akkermansia and Faecalibacterium did not show significant differences, while Oscillospira and Ruminococcus produced statistically significant results but with limited relevance to COVID-19 severity. Our findings reveal new insights into the differential abundance of key bacterial genera in COVID-19, particularly Bifidobacterium and Bacteroides.

Rapid and simultaneous detection of common childhood diarrhea viruses by microfluidic-FEN1-assisted isothermal amplification with ultra-high specificity and sensitivity

Rapid and accurate diagnostic methods are crucial for managing viral gastroenteritis in children, a leading cause of global childhood morbidity and mortality. This study introduces a novel microfluidic-Flap endonuclease 1 (FEN1)-assisted isothermal amplification (MFIA) method for simultaneously detecting major viral pathogens associated with childhood diarrhea-rotavirus, norovirus, and adenovirus. Leveraging the specificity-enhancing properties of FEN1 with a universal dspacer-modified flap probe and the adaptability of microfluidic technology, MFIA demonstrated an exceptional detection limit (5 copies/μL) and specificity in the simultaneous detection of common diarrhea pathogens in clinical samples. Our approach addresses the limitations of current diagnostic techniques by offering a rapid (turn around time <1 h), cost-effective, easy design steps (universal flap design), and excellent detection performance method suitable for multiple applications. The validation of MFIA against the gold-standard PCR method using 150 actual clinical samples showed no statistical difference in the detection performance of the two methods, positioning it as a potential detection tool in pediatric diagnostic virology and public health surveillance. In conclusion, the MFIA method promises to transform pediatric infectious disease diagnostics and contribute significantly to global health efforts combating viral gastroenteritis.

Enteric Pathogen Detection Using Multiplex PCR Assay in Kidney Transplant Recipients with Diarrhea-Retrospective Before-After Study

INTRODUCTION

Diarrhea is a frequent complication after kidney transplantation, however the etiology is often not identified. Multiplex PCR assays may increase the detection of diarrheal pathogens among kidney transplant recipients (KTRs), leading to improved management.

METHODS

This was a retrospective before-after study, conducted in a high-volume transplant center. In September 2017, multiplex PCR assay was introduced. We reviewed all hospitalized KTRs with diarrhea during 1/2015-8/2017 (pre-GI PCR, n = 111) and 9/2017-12/2021 (GI PCR, n = 159) and followed them for 3 years. We performed univariate and multivariate analysis for predictors of pathogen identification, introducing the study period as an independent variable.

RESULTS

Among 270 hospitalized KTRs with diarrhea, 64 (24%) had an identified diarrheal pathogen. The proportion of KTRs with an identified pathogen increased from 20% (13/64) in the pre-GI PCR to 80% (51/64) post GI PCR (p < 0.01). Of 51 KTRs with an identified pathogen in the post GI PCR, 44 (86%) were diagnosed using GI PCR. GI PCR was more likely used in younger KTRs with more recent transplantation and higher creatinine level at admission. The most common non-C. difficile diarrheal pathogens in the post-GI PCR cohort were enteropathogenic Escherichia coli (n = 23, 58%), norovirus (n = 11, 28%), and Campylobacter (n = 11, 28%). Implementing GI PCR significantly increased the detection and identification of GI pathogens (odds ratio [OR] = 21, CI 95% 10-44; p < 0.001).

CONCLUSIONS

Infectious etiologies of diarrhea were identified in a higher proportion of KTRs after the implementation of GI PCR. This emphasizes the importance of integrating this diagnostic tool into diarrhea workup in KTRs.

Assessing the difference in contamination of retail meat with multidrug-resistant bacteria using for-consumer package label claims that indicate on-farm antibiotic use practices- United States, 2016-2019

BACKGROUND

Antibiotic use in food-producing animals can select for antibiotic resistance in bacteria that can be transmitted to people through contamination of food products during meat processing. Contamination resulting in foodborne illness contributes to adverse health outcomes. Some livestock producers have implemented antibiotic use reduction strategies marketed to consumers on regulated retail meat packaging labels ("label claims").

OBJECTIVE

We investigated whether retail meat label claims were associated with isolation of multidrug-resistant organisms (MDROs, resistant to ≥3 classes of antibiotics) from U.S. meat samples.

METHODS

We utilized retail meat data from the U.S. Food and Drug Administration National Antimicrobial Resistance Monitoring System (NARMS) collected during 2016-2019 for bacterial contamination of chicken breast, ground turkey, ground beef, and pork chops. We used modified Poisson regression models to compare the prevalence of MDRO contamination among meat samples with any antibiotic restriction label claims versus those without such claims (i.e., conventionally produced).

RESULTS

In NARMS, 62,338 meat samples were evaluated for bacterial growth from 2016-2019. Of these, 24,446 (39%) samples had label claims that indicated antibiotic use was restricted during animal production. MDROs were isolated from 2252 (4%) meat samples, of which 71% (n = 1591) were conventionally produced, and 29% (n = 661) had antibiotic restriction label claims. Compared with conventional samples, meat with antibiotic restriction label claims had a statistically lower prevalence of MDROs (adjusted prevalence ratio: 0.66; 95% CI: 0.61, 0.73). This relationship was consistent for the outcome of any bacterial growth.

IMPACT

This repeated cross-sectional analysis of a nationally representative retail meat surveillance database in the United States supports that retail meats labeled with antibiotic restriction claims were less likely to be contaminated with MDROs compared with retail meat without such claims during 2016-2019. These findings indicate the potential for the public to become exposed to bacterial pathogens via retail meat and emphasizes a possibility that consumers could reduce their exposure to environmental reservoirs of foodborne pathogens that are resistant to antibiotics.

Genomic epidemiology of ceftriaxone-resistant non-typhoidal Salmonella enterica strain in China

Non-typhoidal Salmonella (NTS) is one of the top causes of diarrhea worldwide. Ceftriaxone is commonly recommended as the initial treatment option for Salmonella infections due to its antibacterial effectiveness. The objective of this study was to investigate the molecular epidemiological characteristics of NTS and to compare the phenotypic and genotypic profiles of antimicrobial resistance in multidrug-resistant Salmonella strains by sequencing 329 NTS strains collected from a county-level hospital between 2018 and 2021. Multi-locus sequence typing (MLST), antimicrobial resistance genes and plasmid types were identified by BacWGSTdb 2.0 webserver. Phylogenetic analysis of all NTS strains was carried out using Snippy and Gubbins software. The transferability of ceftriaxone resistant plasmids was confirmed through plasmid conjugation assays, and verified by S1-PFGE-Southern blot assays. The predominant serotypes among all NTS strains were Typhimurium (161/329), Enteritidis (49/329) and London (45/329). The most common sequence type observed was ST34 (86/329), followed by ST19 (72/329) and ST11 (47/329). The antimicrobial resistance of Salmonella to a wide range of antimicrobials showed an overall increase. Out of these 37 (11.24%) ceftriaxone-resistant strains, with the majority of them (33/37) being blaCTX-M. The predominant plasmid types identified were IncHI2 (14/21) and IncI1 (6/21), ranging in size from 70 kb to 360 kb. The conjugation efficiency was calculated with the high conjugation efficiency of 1.1 × 10- 5 to 9.3 × 10- 2. The strains varied widely, ranging from 3 to 45,024 single nucleotide polymorphisms (SNPs). There are close linkages observed among the predominant lineage, with an average of 78 SNPs between each pair of ST34 strains. The findings contribute to our understanding of the transmission and resistance mechanisms of multidrug-resistant Salmonella, thereby facilitating the development of effective control strategies.

Sapovirus: an emerging pathogen in kidney transplant recipients?

PURPOSE

Diarrhea is an important cause of morbidity and mortality in immunocompromised patients. After including sapovirus to the viral gastroenteritis screening of our institution's laboratory, we noticed an increase in sapovirus infections among kidney transplant recipients. Therefore, we assumed former gastrointestinal tract infections with unidentified pathogens could have been caused by sapovirus. To better understand the characteristics of a sapovirus infection in a high-risk group we initiated this study.

METHODS

Over a period of 6 months, all transplant recipients with diarrhea and later identified viral/unknown pathogens were included. Kidney function, levels of immunosuppressants and  c-reactive protein, acid-base balance, onset of symptoms and time of hospitalization were analyzed.

RESULTS

Among 13 hospitalized kidney transplant recipients sapovirus was detected in four patients, while in the remaining nine, three were diagnosed with norovirus, one with cytomegalovirus, one with inflammatory bowel disease and in four patients no pathogen was identified. Even though statistically not significant, creatinine levels at admission tended to be higher in sapovirus patients (median: sapovirus: 3.3 mg/dl (1.3; 5.0), non-sapovirus: 2.5 mg/dl (1.1; 4.9), p = 0.710). Also, Tacrolimus levels showed the same trend (sapovirus: 13.6 ng/ml (12.9; 13.6), non-sapovirus: 7.1 ng/ml (2.6; 22.6), p = 0.279). On discharge creatinine levels improved equally in both groups (sapovirus: 1.7 mg/dl (1.4; 3.2), non-sapovirus: 2 mg/dl (1.0; 3.6), p = 0.825).

CONCLUSION

In high-risk patients, early symptomatic treatment remains crucial to protect the transplant`s function. In our cohort all patients recovered well. Larger cohorts and longer follow-up times are needed to detect the long-term consequences and a potential need for further research regarding specific treatment.

TRIAL REGISTRATION

The study has been registered on DRKS (trialsearch.who.int), Reg. Nr. DRKS00033311 (December 28th 2023).

Fermented Polyherbal Formulation Restored Ricinoleic Acid-Induced Diarrhea in Sprague Dawley Rats and Exhibited In Vitro Antibacterial Effect on Multiple Antibiotic-Resistant Gastrointestinal Pathogens

The involvement of multiple antibiotic-resistant gastrointestinal pathogens in diarrhea aggravates the disease condition uncontrollably. The current study aimed to find and develop a suitable formulation utilizing multiple natural components from known plant sources to augment the current therapeutic outcomes. The hydroethanolic extraction method was applied through boiling and fermentation on ancient observation-based efficacious plant parts for developing the antidiarrheal polyherbal formulation AP-01. An animal study model of diarrhea was used to evaluate the safety and efficacy of the formulation. The formulation was tested in vitro on four different multiple antibiotic-resistant gastrointestinal pathogens collected from the national repository. The formulation depicted no cytotoxicity on normal gut cells and was efficacious at 10 ml/kg single dose in relieving symptoms of diarrhea by 79.71%, compared with the standard drug showing a reduction of symptoms by 83.01%. AP-01 exhibited delayed gastric motility. The symptoms of diarrhea ceased to occur within 320.66 ± 5.05 minutes with AP-01, whereas the standard drug took 308 ± 6.63 minutes. AP-01 was found successful at a viable dosage regimen of 75 μl/ml v/v to 100 μl/ml v/v in inhibiting the growth of different pathogens from the Enterobacteriaceae family possessing resistance against several classes of antibiotics in culture media. Chemical analysis revealed different alkaloids, flavonoids, and polyphenols that probably work in unison through multiple modes of action to arrest diarrhea and inhibit pathogens simultaneously. These promising results shown by AP-01 should evoke an effort to dive deep into research and development for better therapeutic formulations for infectious diarrhea by harvesting nature's arsenal.

Acute Diarrhea in a Tertiary Emergency Department: From Readmission Determinants to Antibiotic Prescription

Acute diarrhea represents a major public health issue, and the management of adult patients admitted to the emergency department (ED) for this problem is still challenging. In a retrospective analysis on more than 20,000 patients visiting a tertiary ED for acute diarrhea and then being discharged home, we found that age > 65 years, onset of symptoms > 24 h since ED admission, refusal of hospitalization, and a history of chronic renal and liver diseases were independently associated with ED readmission for abdominal symptoms within 7 days. In the younger group, the presence of comorbidities significantly impacted on ED readmission, while fever and alteration of serum creatinine were the main determinants in the older group. Antibiotics were prescribed in about 25% of patients, although diarrhea etiology (viral or bacterial) was usually not available. According to international guidelines, fluoroquinolones were the most prescribed class, showing an inverse correlation to ED readmission. However, β-lactams and probiotics were also commonly prescribed; the latter were independently correlated to ED readmission in the elderly group. A comprehensive, guideline-based approach, including a detailed clinical history and laboratory and comorbidity assessment, should be encouraged to support physicians in the management of different age subgroups of adults admitted to the ED for acute diarrhea.

Multistate outbreaks of salmonellosis linked to contact with backyard poultry-United States, 2015-2022

AIMS

Contact with backyard poultry (i.e., privately-owned, non-commercial poultry) was first associated with a multistate outbreak of salmonellosis in 1955. In recent years, backyard poultry-associated salmonellosis outbreaks have caused more illnesses in the United States than salmonellosis outbreaks linked to any other type of animal. Here, we describe the epidemiology of outbreaks from 2015-2022 to inform prevention efforts.

METHODS AND RESULTS

During 2015-2022, there were 88 multistate backyard poultry-associated salmonellosis outbreaks and 7866 outbreak-associated illnesses caused by 21 different Salmonella serotypes. Salmonella Enteritidis accounted for the most outbreaks (n = 21) and illnesses (n = 2400) of any serotype. Twenty-four percent (1840/7727) of patients with available information were <5 years of age. In total, 30% (1710/5644) of patients were hospitalized, and nine deaths were attributed to Salmonella infection. Throughout this period, patients reported behaviours that have a higher risk of Salmonella transmission, including kissing or snuggling poultry or allowing poultry inside their home.

CONCLUSIONS

Despite ongoing efforts to reduce the burden of salmonellosis associated with backyard poultry, outbreak-associated illnesses have nearly tripled and hospitalizations more than quadrupled compared with those in 1990-2014. Because this public health problem is largely preventable, government officials, human and veterinary healthcare providers, hatcheries, and retailers might improve the prevention of illnesses by widely disseminating health and safety recommendations to the public and by continuing to develop and implement prevention measures to reduce zoonotic transmission of Salmonella by backyard poultry.

Gastrointestinal Ultrasound in Infectious Diseases: A Comprehensive Review

Infectious diseases affecting the gastrointestinal tract often present diagnostic challenges due to the variability in clinical manifestations and overlapping symptoms. Ultrasound imaging has emerged as a valuable tool in the assessment of gastrointestinal pathologies, offering non-invasive and real-time visualization of anatomical structures. This review aims to explore the role of ultrasound in the diagnosis and management of infectious diseases involving the gastrointestinal tract. We discuss the imaging features of various infectious etiologies, such as bacterial, viral, and parasitic infections, highlighting characteristic findings on ultrasound scans. Additionally, we provide insights into the utility of ultrasound for the assessment of treatment response. Through a comprehensive analysis of existing literature and clinical case studies, this review underscores the significance of ultrasound imaging as a frontline modality in the diagnosis and management of infectious diseases affecting the gastrointestinal tract.

Rapid detection of ceftriaxone-resistant Salmonella by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry combined with the ratio of optical density

BACKGROUND

The increased resistance rate of Salmonella to third-generation cephalosporins represented by ceftriaxone (CRO) may result in the failure of the empirical use of third-generation cephalosporins for the treatment of Salmonella infection in children. The present study was conducted to evaluate a novel method for the rapid detection of CRO-resistant Salmonella (CRS).

METHODS

We introduced the concept of the ratio of optical density (ROD) with and without CRO and combined it with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) to establish a new protocol for the rapid detection of CRS.

RESULTS

The optimal incubation time and CRO concentration determined by the model strain test were 2 h and 8 µg/ml, respectively. We then conducted confirmatory tests on 120 clinical strains. According to the receiver operating characteristic curve analysis, the ROD cutoff value for distinguishing CRS and non-CRS strains was 0.818 [area under the curve: 1.000; 95% confidence interval: 0.970-1.000; sensitivity: 100.00%; specificity: 100%; P < 10- 3].

CONCLUSIONS

In conclusion, the protocol for the combined ROD and MALDI-TOF MS represents a rapid, accurate, and economical method for the detection of CRS.

[Syndromic approach in migrant patients: Fever, diarrhea, anemia, eosinophilia and chronic cough]

Migrant patients share the same diseases as natives, but biological or environmental differences may lead to distinct prevalence and manifestations of certain syndromes. Some common conditions in Primary Care stand out, such as fever, diarrhea, anemia, eosinophilia, and chronic cough, where it is important to have a special consideration. Fever may indicate a serious imported illness, and malaria should always be ruled out. Diarrhea is generally of infectious origin, and in most cases, management is outpatient. Anemia may indicate malnutrition or malabsorption, while eosinophilia may indicate a parasitic infection. Lastly, chronic cough may be a sign of tuberculosis, especially in immigrants from endemic areas. Family medicine holds a privileged position for the comprehensive, culturally sensitive, and person-centered approach to these conditions.

Cohen Syndrome With Complex Medical Complications: A Case Report

Cohen syndrome (CS) is a rare autosomal recessive disorder marked by developmental delays, distinct facial features, and a variety of systemic manifestations. We present a case of a 28-year-old male previously misdiagnosed with Prader-Willi syndrome who exhibited recurrent generalized weakness, fever, fatigue, and significant hemoglobin drops requiring multiple blood transfusions due to thalassemia major. The patient displayed characteristic CS features, including developmental delays, distinct facial characteristics, morbid obesity, and heterochromia iridis. Severe gastrointestinal bleeding led to a diagnosis of ulcerative colitis (UC) via colonoscopy. Management included blood transfusions, hydrocortisone, mesalamine, and azathioprine, resulting in stabilized UC and improved overall health. CS presents with a spectrum of clinical features that overlap with other syndromic conditions, necessitating careful differential diagnosis. Early diagnosis and supportive care significantly improve quality of life and help manage complications effectively.

Canadian Association of Radiologists Gastrointestinal Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Gastrointestinal Expert Panel consists of radiologists, a gastroenterologist, a general surgeon, a family physician, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 20 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 58 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 85 recommendation statements specific to the adult population across the 20 scenarios. This guideline presents the methods of development and the referral recommendations for dysphagia/dyspepsia, acute nonlocalized abdominal pain, chronic abdominal pain, inflammatory bowel disease, acute gastrointestinal bleeding, chronic gastrointestinal bleeding/anemia, abnormal liver biopsy, pancreatitis, anorectal diseases, diarrhea, fecal incontinence, and foreign body ingestion.

Comparison of parasitological methods for the identification of soil-transmitted helminths, including Strongyloides stercoralis, in a regional reference laboratory in northwestern Argentina: An observational study

Soil-transmitted helminths (STH) are a significant public health problem in impoverished communities of tropical and subtropical areas. Improved diagnostic methods are crucial for Neglected Tropical Diseases programs, particularly for S. stercoralis, as traditional methods are inadequate. Thus, it is important to identify the most accurate and efficient methods for the diagnosis of STH. We performed a retrospective study analyzing laboratory data at the Instituto de Investigaciones de Enfermedades Tropicales from 2010 to 2019. The study included data from outpatients referred for stool analysis and public health interventions from urban and rural communities in northern Salta province, Argentina. Samples were included in this analysis if processed through sedimentation/concentration, Baermann, Harada-Mori and McMaster's, with a subgroup that also included Agar plate culture method (APC). Sensitivity was calculated against a composite reference standard. Of the 5625 samples collected, 944 qualified for this analysis, with a prevalence of 11.14% for A. lumbricoides, 8.16% for hookworm, 1.38% for T. trichiura, and 6.36% for S. stercoralis. The sedimentation/concentration method was the most sensitive for A. lumbricoides (96%), compared to the McMaster method, with a sensitivity of 62%. Similarly, for hookworms, sedimentation/concentration was more sensitive than McMaster's, Harada-Mori, and Baermann with sensitivities of 87%, 70%, 43%, and 13%, respectively. Most of these infections were of light intensity. For S. stercoralis, Baermann and sedimentation/concentration methods were the most sensitive, with 70% and 62% respectively, while Harada-Mori was the least sensitive. In a subset of 389 samples also analyzed by the APC, Baermann was more sensitive than APC for detecting S. stercoralis, and both methods were superior to Harada-Mori. Parasitological methods, mostly when used combined, offer adequate opportunities for the diagnosis of STH in clinical and public health laboratories. The incorporation of S. stercoralis into the control strategies of the World Health Organization requires rethinking the current diagnostic approach used for surveys. With sedimentation/concentration and Baermann appearing as the most sensitive methods for this species. Further studies, including implementation assessments, should help in identifying the most adequate and feasible all-STH diagnostic approach.

Melting curve analysis reveals false-positive norovirus detection in a molecular syndromic panel

BACKGROUND

Molecular syndromic panels can improve rapidity of results and ease clinical laboratory workflow, although caution has been raised for potential false-positive results. Upon implementation of a new panel for infectious diarrhea (BioFire® FilmArray® Gastrointestinal [GI] Panel, bioMérieux) in our clinical laboratory, a higher than expected number of stool samples with norovirus were detected.

OBJECTIVES

The goal of this study was to investigate positive percent agreement and the false-positive rate of norovirus detected by the multiplex BioFire GI panel compared to a singleplex commercial assay.

STUDY DESIGN

From October 2023 to January 2024, all prospective stool samples with a positive norovirus result by BioFire had melting curves reviewed manually using the BioFire FilmArray Torch System. Stool samples further underwent testing by a supplementary real-time RT-PCR assay (Xpert® Norovirus, Cepheid) for comparative analysis.

RESULTS

Of the 50 stool samples with norovirus detected by BioFire, 18 (36 %) tested negative by Xpert (deemed "false-positives"). Furthermore, melting curve analysis revealed nearly all of these samples had atypical melting curve morphologies for the "Noro-1" target on BioFire (16/18, 89 %), which was statistically significant (Odds Ratio 173.2, 95 % CI [22.2, 5326.9], p < 0.0001). Stool samples with multiple pathogens detected by BioFire including norovirus were not more likely to produce false-positive norovirus results (Odds Ratio 1, 95 % CI [0.3, 3.3], p = 1).

CONCLUSIONS

Although not described in the manufacturer's Instructions for Use, we propose routine manual review of melting curves for the BioFire GI panel prior to reporting, to mitigate potential false-positive norovirus results.

Antimicrobial susceptibility and virulence gene analysis of Shigella species causing dysentery in Iranian children: Implications for fluroquinolone resistance

Shigella species significantly impact global health due to their role in diarrheal diseases. A 2019-2022 cross-sectional study on 432 stool samples from pediatric patients in Mashhad, Iran, identified Shigella spp. and tested their susceptibility to 12 antimicrobials by the disk diffusion method. The presence of virulence factors, namely ipaH, virA, stx1, and stx2, as well as plasmid-mediated quinolone resistance (PMQR) genes, including qnrA, qnrB, qnrC, qnrD, and qnrS, were ascertained through the utilization of polymerase chain reaction techniques. Sequencing of 15 isolates detected mutations within quinolone resistance-determining regions (QRDRs) at the gyrA and parC genes, indicating fluoroquinolone (FQ) resistance. 19.2 % (83/432) of stool samples contained Shigella, primarily S. sonnei (77.1 %), followed by S. flexneri (21.6 %) and S. boydii (1.2 %). Most isolates were from children under five (55.4 %). All strains had the ipaH gene, lacked stx1 and stx2, and 86.7 % had virA. High resistance was noted for ampicillin and tetracycline (84.3 % each), trimethoprim-sulfamethoxazole (81.9 %), and azithromycin (60.2 %). 87.1 % of isolates were multidrug-resistant (MDR). The most common PMQR genes were qnrA and qnrS (41 % each). The qnrD gene, prevalent in 36.1 % of cases, is reported in Iran for the first time. The most common PMQR profile was qnrADS (15.7 %). Resistance to nalidixic acid and ciprofloxacin was 45.8 % and 12 %, respectively. The Shigella isolates exhibited mutations in the gyrA (at codons 83, 87, and 211) and parC (at codons 80, 84, 93, 126, 128, 129, and 132) genes. The D87Y mutation in the gyrA gene was the most common in Shigella isolates, occurring in 73 % of cases. The F93S and L132T mutations in the parC gene were unique to this study. Empirical FQ therapy in patients infected with MDR Shigella, possessing PMQR determinants and/or mutations in the QRDRs of gyrA and parC, may escalate the risks of secondary diseases, extended treatment duration, therapeutic failure, and resistance spread. Consequently, the necessity for continuous surveillance and genetic testing to detect FQ-resistant Shigella strains is of paramount importance.

Practical approach to thrombocytopenia in patients with sepsis: a narrative review

Thrombocytopenia frequently occurs in patients with sepsis. Disseminated intravascular coagulation (DIC) may be a possible cause of thrombocytopenia owing to its high prevalence and association with poor outcomes; however, it is important to keep the presence of other diseases in mind in sepsis practice. Thrombotic microangiopathy (TMA), which is characterized by thrombotic thrombocytopenic purpura, Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (HUS), and complement-mediated HUS, is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ damage. TMA has become widely recognized in recent years because of the development of specific treatments. Previous studies have reported a remarkably lower prevalence of TMA than DIC; however, its epidemiology is not well defined, and there may be cases in which TMA is not correctly diagnosed, resulting in poor outcomes. Therefore, it is important to differentiate DIC from TMA. Nevertheless, differentiating between DIC and TMA remains a challenge as indicated by previous reports that most patients with TMA can be diagnosed as DIC using the universal coagulation scoring system. Several algorithms to differentiate sepsis-related DIC from TMA have been suggested, contributing to improving the care of septic patients with thrombocytopenia; however, it may be difficult to apply these algorithms to patients with coexisting DIC and TMA, which has recently been reported. This review describes the disease characteristics, including epidemiology, pathophysiology, and treatment, of DIC, TMA, and other diseases with thrombocytopenia and proposes a novel practical approach flow, which is characterized by the initiation of the diagnosis of TMA in parallel with the diagnosis of DIC. This practical flow also refers to the longitudinal diagnosis and treatment flow with TMA in mind and real clinical timeframes. In conclusion, we aim to widely disseminate the results of this review that emphasize the importance of incorporating consideration of TMA in the management of septic DIC. We anticipate that this practical new approach for the diagnostic and treatment flow will lead to the appropriate diagnosis and treatment of complex cases, improve patient outcomes, and generate new epidemiological evidence regarding TMA.

Emerging Strategies against Non-Typhoidal Salmonella: From Pathogenesis to Treatment

Even with the intensive efforts by public health programs to control and prevent it, non-typhoidal Salmonella (NTS) infection remains an important public health challenge. It is responsible for approximately 150 million illnesses and 60,000 deaths worldwide annually. NTS infection poses significant risks with high rates of morbidity and mortality, leading to potential short- and long-term complications. There is growing concern among health authorities about the increasing incidence of antimicrobial resistance, with multidrug resistance totaling 22.6% in Europe, highlighting an urgent need for new therapeutic approaches. Our review aims to provide a comprehensive overview of NTS infection. We outline the molecular mechanisms involved in the pathogenesis of NTS infection, as well as the events leading to invasive NTS infection and the subsequent complications associated with it. Given the widespread implications of antimicrobial resistance, our review also presents the global landscape of resistance, including multidrug resistance, and delve into the underlying mechanisms driving this resistance. The rising rates of antibiotic resistance frequently lead to treatment failures, emphasizing the importance of investigating alternative therapeutic options. Therefore, in this review we also explore potential alternative therapies that could offer promising approaches to treating NTS infections.

Multiplex Gastrointestinal Panel Testing in Hospitalized Patients With Acute Diarrhea in Thailand

Background

Multiplex gastrointestinal (GI) panel testing is widely used for outpatient diagnosis of diarrhea. However, the clinical practicality of multiplex testing in hospitalized diarrheal subjects has not yet been thoroughly elucidated.

Methods

We enrolled hospitalized subjects with acute diarrhea. The subjects' stool samples were collected in triplicate; 1 sample was tested using traditional diagnoses, and the other 2 were tested using Allplex (AP) and FilmArray (FA) GI panel testing. Clinical data were reviewed and analyzed.

Results

Of the 199 subjects, 92 (46.5%) were male, and the mean age was 66.3 years. The median (interquartile range) onset of diarrhea was 6 (2--14) days after hospitalization. One hundred fifty-one patients (75.9%) had sepsis, and 166 (83.4%) had received prior or were receiving current antimicrobial therapy. Positive stool cultures were obtained from 4/89 (4.5%), and Clostridioides difficile toxin gene tests were positive in 14/188 (7.4%) patients. AP and FA multiplex tests were positive for GI pathogens in 49/199 (24.6%) and 40/199 (20.1%), respectively. The target most frequently detected by AP was Aeromonas spp. Both assays commonly detected enteropathogenic E. coli (EPEC), C. difficile toxin gene, and Salmonella spp.; neither assay detected pathogens in 75.4% and 79.9%. Fever (odds ratio [OR], 2.05; 95% CI, 1.08-3.88; P = .028), watery diarrhea (OR, 2.69; 95% CI, 1.25-5.80; P = .011), and antimicrobial therapy (OR, 2.60; 95% CI, 1.18-5.71; P = .018) were independent factors associated with the negative multiplex test result.

Conclusions

Multiplex GI panel testing effectively detects enteric pathogens associated with diarrhea in hospitalized subjects. The etiology remains undiagnosed in >75% of cases. Factors contributing to negative test results should be considered before implementing the tests.

Gastrointestinal Panel Performance for the Diagnosis of Acute Gastroenteritis in Pediatric Patients

BACKGROUND

Various methods are used to identify the causative organisms of acute gastroenteritis (AGE) in children. The gastrointestinal (GI) panel has the potential to detect up to 22 pathogens rapidly through the multiplex real-time PCR test. We studied the impact of the GI panel on clinical management in the pediatric population.

METHODS

A retrospective study was conducted to collect data on GI panel results and clinical details of inpatient children presenting with AGE at King Hamad University Hospital, Kingdom of Bahrain, over the course of one year.

RESULTS

One hundred nine samples were collected. The GI panel was positive in 96 samples (88.1%), with the majority detected in the toddler age group. Forty-one (42.7%) samples were positive for at least one organism. Salmonella was the most frequently encountered bacteria as a single isolate, 10/55 (18.2%), while enteropathogenic Escherichia coli was the most common co-infected organism, 16/41 (39%). Norovirus was the most common virus among the viruses. Bacterial detection peaked from July to October, while viral detection plateaued throughout the year. The GI panel and stool culture were positive for the same organism in 17 samples, versus one sample with a different organism. Sixty-two (56.9%) samples had a positive GI panel but negative stool cultures and stool analysis, and half of those detected viruses. The GI panel was positive in 86.2% of severely ill patients; the majority were bacteria. Bacterial detection was associated with a higher CRP compared to viruses.

CONCLUSION

The GI panel is an informative tool for detecting the causative pathogen of AGE in children. However, it can detect multiple organisms, indicating a possible carrier status, which points toward future studies.

Giardiasis Presenting as a Brunner Gland Hyperplasia

Giardiasis is the most common intestinal parasitic disease worldwide. Clinical presentation ranges from asymptomatic to abdominal pain, diarrhea, and iron deficiency anemia. Treatment modalities include tinidazole, metronidazole, and paromomycin. We present a case of an adult man with anemia and suspected gastrointestinal bleeding who was found to have a duodenal nodule consistent with Brunner gland hyperplasia, and biopsy also showed Giardia. Limited case reports of Giardia diagnosed by duodenal biopsy are found in the literature. To the best of our knowledge, this is the first report of giardiasis presenting as Brunner gland hyperplasia.

Outbreak of multidrug-resistant Salmonella infections in people linked to pig ear pet treats, United States, 2015-2019: results of a multistate investigation

Background

International distribution of contaminated foods can be a source of Salmonella infections in people and can contribute to the spread of antimicrobial-resistant bacteria across countries. We report an investigation led by the United States Centers for Disease Control and Prevention, the Food and Drug Administration (FDA), and state governmental officials into a multistate outbreak of salmonellosis linked to pig ear pet treats.

Methods

Pig ear treats and companion dogs were tested for Salmonella by state officials and the FDA. Products were traced back to the country of origin when possible. Cases were defined as outbreak illnesses in people associated with one of seven Salmonella serotypes genetically related to samples from pig ear pet treats, with isolation dates from June 2015 to September 2019. Whole genome sequencing (WGS) of isolates was used to predict antimicrobial resistance.

Findings

The outbreak included 154 human cases in 34 states. Of these, 107 of 122 (88%) patients reported dog contact, and 65 of 97 (67%) reported contact with pig ear pet treats. Salmonella was isolated from 137 pig ear treats, including some imported from Argentina, Brazil, and Colombia, and from four dogs. WGS predicted 77% (105/137) of human and 43% (58/135) of pig ear treat isolates were resistant to ≥3 antimicrobial classes.

Interpretation

This was the first documented United States multistate outbreak of Salmonella infections linked to pig ear pet treats. This multidrug-resistant outbreak highlights the interconnectedness of human health and companion animal ownership and the need for zoonotic pathogen surveillance to prevent human illness resulting from internationally transported pet food products.

Funding

Animal Feed Regulatory Program Standards award. Animal and product testing conducted by FDA Vet-LIRN was funded by Vet-LIRN infrastructure grants (PAR-22-063).

Multidrug resistance in Salmonella isolates of swine origin: mobile genetic elements and plasmids associated with cephalosporin resistance with potential transmission to humans

The emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context requiring continuous surveillance. Resistance to ciprofloxacin and cephalosporins is of particular concern. Since pigs are a relevant source of foodborne Salmonella for human beings, we studied transmissible AMR genes and MGE in a collection of 83 strains showing 9 different serovars and 15 patterns of multidrug resistant (MDR) previously isolated from pigs raised in the conventional breeding system of Northern Spain. All isolates were susceptible to ciprofloxacin and three isolates carried blaCMY-2 or blaCTX-M-9 genes responsible for cefotaxime resistance. Filter mating experiments showed that the two plasmids carrying blaCTX-M-9 were conjugative while that carrying blaCMY-2 was self-transmissible by transformation. Whole-genome sequencing and comparative analyses were performed on the isolates and plasmids. The IncC plasmid pSB109, carrying blaCMY-2, was similar to one found in S. Reading from cattle, indicating potential horizontal transfer between serovars and animal sources. The IncHI2 plasmids pSH102 in S. Heidelberg and pSTM45 in S. Typhimurium ST34, carrying blaCTX-M-9, shared similar backbones and two novel "complex class 1 integrons" containing different AMR and heavy metal genes. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.IMPORTANCEThe emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context. Since pigs are a relevant source of foodborne Salmonella for humans, in this study, we investigate different aspects of AMR in a collection of 83 Salmonella showing nine different serovars and 15 patterns of multidrug resistant (MDR) isolated from pigs raised in the conventional breeding system. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.

Extended-Spectrum Beta-Lactamase Shigella sonnei Cluster Among Men Who Have Sex with Men in Chicago, Illinois-July-October 2022

Drug-resistant shigellosis is increasing, particularly among men who have sex with men (MSM). During July-October 2022, an extended-spectrum beta-lactamase producing Shigella sonnei cluster of 9 patients was identified in Chicago, of whom 8 were MSM and 6 were festival attendees. The cluster also included 4 domestic travelers to Chicago. Sexual health care for MSM should include shigellosis diagnosis and prevention.

How New Regulation of Laboratory-Developed Antimicrobial Susceptibility Tests Will Affect Infectious Diseases Clinical Practice

Antimicrobial resistance (AMR) affects 2.8 million Americans annually. AMR is identified through antimicrobial susceptibility testing (AST), but current and proposed regulatory policies from the United States Food and Drug Administration (FDA) jeopardize the future availability of AST for many microorganisms. Devices that perform AST must be cleared by the FDA using their susceptibility test interpretive criteria, also known as breakpoints. The FDA list of breakpoints is relatively short. Today, laboratories supplement FDA breakpoints using breakpoints published by the Clinical and Laboratory Standards Institute, using legacy devices and laboratory-developed tests (LDTs). FDA proposes to regulate LDTs, and with no FDA breakpoints for many drug-bug combinations, the risk is loss of AST for key clinical indications and stifling innovation in technology development. Effective solutions require collaboration between manufacturers, infectious diseases clinicians, pharmacists, laboratories, and the FDA.

Shiga Toxin-Producing Escherichia coli O157:H7 Illness Outbreak Associated with Untreated, Pressurized, Municipal Irrigation Water - Utah, 2023

During July-September 2023, an outbreak of Shiga toxin-producing Escherichia coli O157:H7 illness among children in city A, Utah, caused 13 confirmed illnesses; seven patients were hospitalized, including two with hemolytic uremic syndrome. Local, state, and federal public health partners investigating the outbreak linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW) exposure in city A; 12 of 13 ill children reported playing in or drinking UPMIW. Clinical isolates were genetically highly related to one another and to environmental isolates from multiple locations within city A's UPMIW system. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of UPMIW. Public health and city A officials issued multiple press releases regarding the outbreak reminding residents that UPMIW is not intended for drinking or recreation. Public education and UPMIW management and operations interventions, including assessing and mitigating potential contamination sources, covering UPMIW sources and reservoirs, indicating UPMIW lines and spigots with a designated color, and providing conspicuous signage to communicate risk and intended use might help prevent future UPMIW-associated illnesses.

Fecal leukocyte frequency in children with acute viral gastroenteritis: a single-center experience

OBJECTIVE

Our objective was to determine the frequency of rotavirus, adenovirus, and rota-adenovirus co-infections and investigate the fecal leukocyte rate associated with these infections in patients with gastroenteritis.

METHODS

This is a retrospective study. We identified patients who were admitted to the pediatric emergency department with acute gastroenteritis and had their stool samples tested for rotavirus and/or adenovirus antigens. Among them, we determined the individuals who underwent stool microscopy tests on the same day and recorded their results.

RESULTS

A total of 1,577 patients who underwent testing for rotavirus and/or adenovirus antigens in their stool samples were identified. Among these patients, 583 individuals had concurrent fecal microscopy results. The prevalence of solely rotavirus antigen positivity was 16.4%, solely adenovirus antigen positivity was 2.9%, and rota-adenovirus co-infections were detected in 1.8% of the children. The fecal leukocyte rates in children infected with rotavirus, adenovirus, and rota-adenovirus co-infections were 4.8, 13.3, and 88.9%, respectively.

CONCLUSION

The presence of fecal leukocytes was detected at a high rate in cases of viral gastroenteritis, especially in rota-adenovirus co-infections. Therefore, clinicians should not consider only bacterial pathogens in the presence of fecal leukocytes.

Etiologies of bloody diarrhea in children presenting with acute gastroenteritis to US emergency departments

Among 111 children presenting with bloody diarrhea in a multicenter study of molecular testing in US emergency departments, we found viral pathogens in 18%, bacteria in 48%, protozoa in 2%, and no pathogens detected in 38%.

Meningitis and Bacteremia by Unusual Serotype of Salmonella enterica Strain: A Whole Genome Analysis

Background

Although meningitis caused by Salmonella species is relatively rare and accounts for <1% of the confirmed cases in neonates, it is associated with case complications and fatality rates up to 50-70% when compared to other forms of Gram-negative bacilli meningitis.

Objectives

We conducted an investigation into the first reported case of neonatal meningitis caused by nontyphoidal S. enterica in Jazan, a region in the southwestern part of Saudi Arabia.

Methods

CSF and blood culture were collected from a female neonate patient to confirm the presence of bacterial meningitis. WGS was conducted to find out the comprehensive genomic characterization of S. enterica isolate.

Results

A 3-week-old infant was admitted to a local hospital with fever, poor feeding, and hypoactivity. She was diagnosed with Salmonella meningitis and bacteremia caused by S. enterica, which was sensitive to all antimicrobials tested. WGS revealed the specific strain to be S. enterica serotype Johannesburg JZ01, belonging to ST515 and cgMLST 304742.

Conclusions

We presented a genomic report of rare case of NTS meningitis in an infant who is living in a rural town in Jazan region, Saudi Arabia. Further research is required to understand the impact of host genetic factors on invasive nontyphoidal Salmonella infection.

Clinical Impact of Multiplex Molecular Diagnostic Testing in Children With Acute Gastroenteritis Presenting to an Emergency Department: A Multicenter Prospective Study

BACKGROUND

Multiplex molecular diagnostic panels have greatly enhanced detection of gastrointestinal pathogens. However, data on the impact of these tests on clinical and patient-centered outcomes are limited.

METHODS

We conducted a prospective, multicenter, stepped-wedge trial to determine the impact of multiplex molecular testing at 5 academic children's hospitals on children presenting to the emergency department with acute gastroenteritis. Caregivers were interviewed on enrollment and 7-10 days after enrollment to determine symptoms, risk factors, subsequent medical visits, and impact on family members. During the pre-intervention period, diagnostic testing was performed at the clinician's discretion . During the intervention period, multiplex molecular testing was performed on all children, with results available to clinicians. The primary outcome was return visits to a healthcare provider within 10 days of enrollment.

RESULTS

Potential pathogens were identified by clinician-ordered tests in 19 of 571 (3.3%) in the pre-intervention period compared with 434 of 586 (74%) in the intervention period; clinically relevant pathogens were detected in 2.1% and 15%, respectively. In the multivariate model, the intervention was associated with a 21% reduction in the odds of any return visit (odds ratio, 0.79; 95% confidence interval, .70-.90) after adjusting for potential confounders. Appropriate treatment was prescribed in 11.3% compared with 19.6% during the intervention period (P = .22).

CONCLUSIONS

Routine molecular multiplex testing for all children who presented to the ED with acute gastroenteritis detected more clinically relevant pathogens and led to a 21% decrease in return visits. Additional research is needed to define patients most likely to benefit from testing. Clinical Trials Registration. NCT02248285.

Managing infectious diarrhea among young children in community pharmacies in Saudi Arabia and the implications for AMR

Introduction

Diarrhea remains a major global health issue for children under five, contributing substantially to morbidity and mortality. Community pharmacists play a pivotal role in the management of these children; however, their competence in managing childhood diarrhea in Saudi Arabia is under-researched. This is important to ensure optimal patient care.

Method

Simulated patients (SPs) presenting with three pediatric diarrhea scenarios were used to evaluate pharmacists' practice in terms of their counselling, history taking, over-the-counter (OTC) prescribing, medication instructions, diet/fluid advice, and/or information provision. Pharmacists' practice was categorized into adequate, less adequate, and poor.

Results

182 community pharmacists, primarily male and non-Saudi, participated in the study, of which 60% were in chain pharmacies. Only 5% showed adequate practice in currently managing pediatric diarrhea. Of the 182 simulated patient visits, 62% received medication in all three scenarios and 20% were referred to physicians, with 16% of pharmacists failing to provide any form of intervention. The main medications recommended were kaolin (34%), pectin (34%) and metronidazole (11%). While most pharmacists (86%) asked about the patient's identity and age, 15% provided incorrect management information, 16% failed to provide guidance on the prescribed medicines, and 18% dispensed antimicrobials without a valid prescription.

Conclusion

A high level of inadequate management of pediatric diarrhea in Saudi Arabia was observed. This highlights the need for extensive training to improve community pharmacists' practice in service delivery including providing counselling and advice on the appropriate management of childhood diarrhea. The latter is particularly important to reduce antimicrobial resistance.

Bacterial Flora and Treatment Strategies in Women With Escherichia coli Urinary Tract Infections

Introduction This study explores the intricate relationship between bacterial flora and the occurrence of Escherichia coli (E. coli) infections in gynecological patients. It aims to provide insights into the various treatment strategies used to effectively manage bacterial pathogens, especially E. coli infections. By conducting a comprehensive analysis of the bacterial flora in gynecological patients, the study highlights the notable presence of E. coli, prompting further investigation into the factors that contribute to its colonization. The objective of the study is to comprehensively investigate and detect urinary tract infections (UTIs) specifically caused by E. coli among gynecological patients. The study aims to delve into bacterial flora prevalence, antibiotic resistance patterns, and potential virulence factors. Through this analysis, the study intends to identify effective strategies for rapid detection and diagnosis of UTIs caused by E. coli by utilizing advanced microbiological and molecular techniques. Furthermore, the study aims to formulate and propose a strategic treatment approach with a particular emphasis on selecting appropriate antibiotics to reduce the risk of severe infections and associated complications. Materials and methods The methodology employed in this study included the isolation and characterization of bacterial strains from clinical samples obtained from gynecological patients. A total of 52 urine specimens were collected from patients with complaints of infection in the urinary tract and infertility. These samples underwent both preliminary and confirmatory microbiological analysis, such as gram staining, biochemical confirmation test, and antibiotic susceptibility, and further proceeded with the multiplex polymerase chain reaction (PCR) technique. The results of PCR and antibiotic susceptibility revealed the specific gene involvement and resistant characteristics of E. coli. Results The findings revealed a total of 32 specimens positive for E. coli, of which 10 patients had infertility complaints and 22 patients had UTIs. The preliminary test, gram staining, showed the gram-negative bacilli E. coli, and the nutrient agar plate revealed smooth circular translucent colonies; MacConkey agar showed pink-colored lactose-fermented colonies; and the blood and chocolate agar plates showed grayish white moist gamma-hemolytic colonies. The biochemical confirmation of E. coli resulted in positive for indole and methyl red tests and negative for Voges-Proskauer and citrate utilization tests. The multiplex PCR analysis confirmed the E. coli strains with the presence of two target genes, stx2d and stx2e. Conclusion To summarize, this study offers valuable insights into the bacterial flora of gynecological patients impacted by E. coli infections, which provides a foundation for the development of precise and efficient treatment strategies. The results emphasize the importance of personalized treatment approaches that consider both the microbiological characteristics of the infection and the evolving landscape of antibiotic resistance. The implication of this research extends to enhancing clinical outcomes and alleviating the burden of E. coli infections in gynecological settings.