Thrombotic Risk Assessment in Patients with Lymphoid Neoplasm seen at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State

BACKGROUND

Venous thromboembolism (VTE) is a cause of increased morbidity and mortality in cancer patients. VTE is the second leading cause of death in cancer patients. Risk assessment models have been developed to identify patients at risk of VTE for thromboprophylaxis. Risk scores of patients in our environment have not been adequately investigated.

OBJECTIVE

The study evaluates the association of thrombotic risk assessment scores (using the modified Khorana risk assessment tool) and soluble P-selectin levels with thrombotic events in patients with lymphoid cancer.

METHODS

This is a comparative cross-sectional study conducted at Nnamdi Azikiwe University Teaching Hospital (NAUTH, Nnewi, Anambra State). Forty-five patients with lymphoid malignancy and 45 apparently healthy subjects participated in the study. The modified Khorana risk assessment score was used to assess cancer-associated thrombotic risk. Blood sample was collected for soluble P-selectin estimation. Data were analyzed with SPSS version 23.

RESULTS

The age of subjects with lymphoid neoplasm and controls were 49.1±15.8 years, and 49.6±11.1 years respectively (p = 0.548). Subjects with lymphoid neoplasm consist of 26 (57.8%) males and 19 (42.2%) females while the controls consist of 25 (55.6%) males and 20 (44.4%) females. Non-Hodgkin's lymphoma was the most frequent of lymphoid neoplasm (18, 40.0%), followed by multiple myeloma (10, 22%), CLL (9, 20%), ALL (6, 13.0%) and Hodgkin's lymphoma (2, 4.0%). Thirty-five (77.8%) subjects with lymphoid neoplasm had intermediate risk scores and 10 (22.2%) had high-risk scores. Nineteen (42.2%) of the controls had intermediate risk and 26 (57.8%) low risk. The differences in proportion were statistically significant (p < 0.001). The median (IQR) levels of soluble P-selectin were significantly higher in patients with lymphoid neoplasm (12.2 vs. 7.0ng/mL, p <0.001). Three (6.6%) patients with lymphoid malignancies had deep vein thrombosis confirmed by a Doppler ultrasound scan.

CONCLUSION

Lymphoid malignancy is associated with relatively higher thrombotic risk scores, sP-selectin levels, and venous thromboembolic events.

CONTEXTE

La thromboembolie veineuse (TEV) est une cause de morbidité et de mortalité accrues chez les patients atteints de cancer. La TEV est la deuxième cause de décès chez les patients atteints de cancer. Des modèles d’évaluation des risques ont été mis au point pour identifier les patients présentant un risque de TEV en vue d’une thromboprophylaxie. Les scores de risque des patients dans notre environnement n’ont pas été étudiés de manière adéquate.

OBJECTIF

L’étude évalue l’association des scores d’évaluation du risque thrombotique (en utilisant l’outil modifié d’évaluation du risque de Khorana) et des niveaux de P-sélectine soluble avec les événements thrombotiques chez les patients atteints d’un cancer lymphoïde.

MÉTHODES

Il s’agit d’une étude transversale comparative menée au Nnamdi Azikiwe University Teaching Hospital (NAUTH, Nnewi, État d’Anambra). Quarante-cinq patients atteints d’un cancer lymphoïde et 45 sujets apparemment sains ont participé à l’étude. Le score modifié d’évaluation du risque de Khorana a été utilisé pour évaluer le risque thrombotique associé au cancer. Un échantillon de sang a été prélevé pour l’estimation de la P-sélectine soluble. Les données ont été analysées avec SPSS version 23.

RÉSULTATS

L’âge des sujets atteints de néoplasme lymphoïde et des témoins était respectivement de 49,1±15,8 ans et 49,6±11,1 ans (p = 0,548). Les sujets atteints de néoplasme lymphoïde sont 26 (57,8 %) hommes et 19 (42,2 %) femmes, tandis que les témoins sont 25 (55,6 %) hommes et 20 (44,4 %) femmes. Le lymphome non hodgkinien était le néoplasme lymphoïde le plus fréquent (18, 40 %), suivi du myélome multiple (10, 22 %), de la LLC (9, 20 %), de la LAL (6, 13 %) et du lymphome hodgkinien (2, 4 %). Trente-cinq (77,8 %) sujets atteints de néoplasmes lymphoïdes présentaient un score de risque intermédiaire et 10 (22,2 %) un score de risque élevé. Dix-neuf (42,2 %) des témoins présentaient un risque intermédiaire et 26 (57,8 %) un risque faible. Les différences de proportion étaient statistiquement significatives (p < 0,001). Les niveaux médians (IQR) de P-sélectine soluble étaient significativement plus élevés chez les patients atteints de néoplasme lymphoïde (12,2 vs. 7,0 ng/mL, p <0,001). Trois (6,6 %) patients atteints de tumeurs lymphoïdes ont présenté une thrombose veineuse profonde confirmée par une échographie Doppler.

CONCLUSION

Les tumeurs malignes lymphoïdes sont associées à des scores de risque thrombotique, des taux de sP-sélectine et des événements thromboemboliques veineux relativement plus élevés.

Mots-clés

Malignité lymphoïde, Thrombose, P-sélectine soluble, Scores d’évaluation du risqué.

Influenza Vaccination in Health Centers During the Coronavirus Disease 2019 Pandemic-United States, 7-27 November 2020

BACKGROUND

Influenza vaccination is the most effective way to prevent influenza and influenza-associated complications including those leading to hospitalization. Resources otherwise used for influenza could support caring for patients with coronavirus disease 2019 (COVID-19). The Health Resources and Services Administration (HRSA) Health Center Program serves 30 million people annually by providing comprehensive primary healthcare, including influenza vaccination, to demographically diverse and historically underserved communities. Because racial and ethnic minority groups have been disproportionately affected by COVID-19, the objective of this analysis was to assess disparities in influenza vaccination at HRSA-funded health centers during the COVID-19 pandemic.

METHODS

The Centers for Disease Control and Prevention and HRSA analyzed cross-sectional data on influenza vaccinations from a weekly, voluntary health center COVID-19 survey after addition of an influenza-related question covering 7-11 November 2020.

RESULTS

During the 3-week period, 1126 of 1385 health centers (81%) responded to the survey. Most of the 811 738 influenza vaccinations took place in urban areas and in the Western US region. There were disproportionately more health center influenza vaccinations among racial and ethnic minorities in comparison with county demographics, except among non-Hispanic blacks and American Indian/Alaska Natives.

CONCLUSIONS

HRSA-funded health centers were able to quickly vaccinate large numbers of mostly racial or ethnic minority populations, disproportionately more than county demographics. However, additional efforts might be needed to reach specific racial populations and persons in rural areas. Success in influenza vaccination efforts can support success in severe acute respiratory syndrome coronavirus 2 vaccination efforts.

Testing early warning and response systems through a full-scale exercise in Vietnam

Background

Simulation exercises can functionally validate World Health Organization (WHO) International Health Regulations (IHR 2005) core capacities. In 2018, the Vietnam Ministry of Health (MOH) conducted a full-scale exercise (FSX) in response to cases of severe viral pneumonia with subsequent laboratory confirmation for Middle East Respiratory Syndrome Coronavirus (MERS-CoV) to evaluate the country’s early warning and response capabilities for high-risk events.

Methods

An exercise planning team designed a complex fictitious scenario beginning with one case of severe viral pneumonia presenting at the hospital level and developed all the materials required for the exercise. Actors, controllers and evaluators were trained. In August 2018, a 3-day exercise was conducted in Quang Ninh province and Hanoi city, with participation of public health partners at the community, district, province, regional and national levels. Immediate debriefings and an after-action review were conducted after all exercise activities. Participants assessed overall exercise design, conduction and usefulness.

Results

FSX findings demonstrated that the event-based surveillance component of the MOH surveillance system worked optimally at different administrative levels. Detection and reporting of signals at the community and health facility levels were appropriate. Triage, verification and risk assessment were successfully implemented to identify a high-risk event and trigger timely response. The FSX identified infection control, coordination with internal and external response partners and process documentation as response challenges. Participants positively evaluated the exercise training and design.

Conclusions

This exercise documents the value of exercising surveillance capabilities as part of a real-time operational scenario before facing a true emergency. The timing of this exercise and choice of disease scenario was particularly fortuitous given the subsequent appearance of COVID-19. As a result of this exercise and subsequent improvements made by the MOH, the country may have been better able to deal with the emergence of SARS-CoV-2 and contain it.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10402-x.

Community-Based Surveillance in Côte d'Ivoire

Community-based surveillance can be an important component of early warning systems. In 2016, the Côte d'Ivoire Ministry of Health launched a community-based surveillance project in 3 districts along the Guinea border. Community health workers were trained in detection and immediate reporting of diseases and events using a text-messaging platform. In December 2017, surveillance data from before and after implementation of community-based surveillance were analyzed in intervention and control districts. A total of 3,734 signals of priority diseases and 4,918 unusual health events were reported, of which 420 were investigated as suspect diseases and none were investigated as unusual health events. Of the 420 suspected cases reported, 23 (6%) were laboratory confirmed for a specific pathogen. Following implementation of community-based surveillance, 5-fold and 8-fold increases in reporting of suspected measles and yellow fever clusters, respectively, were documented. Reporting incidence rates in intervention districts for suspected measles, yellow fever, and acute flaccid paralysis were significantly higher after implementation, with a difference of 29.2, 19.0, and 2.5 cases per 100,000 person-years, respectively. All rate differences were significantly higher in intervention districts (p < 0.05); no significant increase in reporting was noted in control districts. These findings suggest that community-based surveillance strengthened detection and reporting capacity for several suspect priority diseases and events. However, the surveillance program was very sensitive, resulting in numerous false-positives. Learning from the community-based surveillance implementation experience, the ministry of health is revising signal definitions to reduce sensitivity and increase specificity, reviewing training materials, considering scaling up sustainable reporting platforms, and standardizing community health worker roles.

Community-based surveillance advances the Global Health Security Agenda in Ghana

Ghana Health Service (GHS) has strengthened community-based surveillance (CBS) to facilitate early detection and rapid reporting of health events of all origins. Since June 2017, GHS has employed an event-based surveillance approach at the community level in a phased manner. CBS coverage has broadened from 2 to 30 districts across Ghana. Through this effort, capacity was built across all administrative levels in these districts to detect, report, triage, and verify signals, and to perform risk assessment and investigate events. Data were collected and analyzed during an evaluation of initial 2-district implementation in March 2018 and during expanded 30-district implementation in March 2019. Between September 2018 and March 2019, 317 health events were detected through CBS. These events included vaccine-preventable disease cases, acute hemorrhagic conjunctivitis outbreaks, clusters of unexpected animal deaths, and foodborne illness clusters. Eighty-nine percent of the 317 events were reported to district-level public health staff within 24 hours of detection at the community level, and 87% of all detected events were responded to within 48 hours of detection. CBS detected 26% of all suspected vaccine-preventable disease cases that were reported from implementing districts through routine disease surveillance. GHS strengthened CBS in Ghana to function as an early warning system for health events of all origins, advancing the Global Health Security Agenda.

Developing monitoring and evaluation tools for event-based surveillance: experience from Vietnam

BACKGROUND

In 2016-2017, Vietnam's Ministry of Health (MoH) implemented an event-based surveillance (EBS) pilot project in six provinces as part of Global Health Security Agenda (GHSA) efforts. This manuscript describes development and design of tools for monitoring and evaluation (M&E) of EBS in Vietnam.

METHODS

A strategic EBS framework was developed based on the EBS implementation pilot project's goals and objectives. The main process and outcome components were identified and included input, activities, outputs, and outcome indicators. M&E tools were developed to collect quantitative and qualitative data. The tools included a supervisory checklist, a desk review tool, a key informant interview guide, a focus group discussion guide, a timeliness form, and an online acceptability survey. An evaluation team conducted field visits for assessment of EBS 5-9 months after implementation.

RESULTS

The quantitative data collected provided evidence on the number and type of events that were being reported, the timeliness of the system, and the event-to-signal ratio. The qualitative and subjective data collected helped to increase understanding of the system's field utility and acceptance by field staff, reasons for non-compliance with established guidelines, and other factors influencing implementation.

CONCLUSIONS

The use of M&E tools for the EBS pilot project in Vietnam provided data on signals and events reported, timeliness of reporting and response, perceptions and opinions of implementers, and fidelity of EBS implementation. These data were valuable for Vietnam's MoH to understand the function of the EBS program, and the success and challenges of implementing this project in Vietnam.

Strengthening timely detection and reporting of unusual respiratory events from health facilities in Yaoundé, Cameroon

BACKGROUND

The International Health Regulations state that early detection and immediate reporting of unusual health events is important for early warning and response systems.

OBJECTIVE

To describe a pilot surveillance program established in health facilities in Yaoundé, Cameroon in 2017 which aimed to enable detection and reporting of public health events.

METHODS

Cameroon's Ministry of Health, in partnership with the US Centers for Disease Control and Prevention, Cameroon Pasteur Center, and National Public Health Laboratory, implemented event-based surveillance (EBS) in nine Yaoundé health facilities. Four signals were defined that could indicate possible public health events, and a reporting, triage, and verification system was established among partner organizations. A pre-defined laboratory algorithm was defined, and a series of workshops trained health facilities, laboratory, and public health staff for surveillance implementation.

RESULTS

From May 2017 to January 2018, 30 signals were detected, corresponding to 15 unusual respiratory events. All health facilities reported a signal at least once, and more than three-quarters of health facilities reported ≥2 times. Among specimens tested, the pathogens detected included Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus, Pneumocystis jiroveci, influenza A (H1N1) virus, rhinovirus, and adenovirus.

CONCLUSIONS

The events detected in this pilot were caused by routine respiratory bacteria and viruses, and no novel influenza viruses or other emerging respiratory threats were identified. The surveillance system, however, strengthened relationships and communication linkages between health facilities and public health authorities. Astute clinicians can play a critical role in early detection and EBS is one approach that may enable reporting of emerging outbreaks and public health events.

Event-Based Surveillance at Community and Healthcare Facilities, Vietnam, 2016-2017

Surveillance and outbreak reporting systems in Vietnam required improvements to function effectively as early warning and response systems. Accordingly, the Ministry of Health of Vietnam, in collaboration with the US Centers for Disease Control and Prevention, launched a pilot project in 2016 focusing on community and hospital event–based surveillance. The pilot was implemented in 4 of Vietnam’s 63 provinces. The pilot demonstrated that event-based surveillance resulted in early detection and reporting of outbreaks, improved collaboration between the healthcare facilities and preventive sectors of the ministry, and increased community participation in surveillance and reporting.

Factors Influencing Community Event-based Surveillance: Lessons Learned from Pilot Implementation in Vietnam

Community event-based surveillance aims to enhance the early detection of emerging public health threats and thus build health security. The Ministry of Health of Vietnam launched a community event-based surveillance pilot program in 6 provinces to improve the early warning functions of the existing surveillance system. An evaluation of the pilot program took place in 2017 and 2018. Data from this evaluation were analyzed to determine which factors were associated with increased detection and reporting. Results show that a number of small, local events were detected and reported through community event-based surveillance, supporting the notion that it would also facilitate the rapid detection and reporting of potentially larger events or outbreaks. The study showed the value of supportive supervision and monitoring to sustain community health worker reporting and the importance of conducting evaluations for community event-based surveillance programs to identify barriers to effective implementation.

Abstract P5-09-09: CHEK2: the third susceptibility BReast CAncer (BC) gene?

INTRODUTION:

Considered a medium penetrance gene, CHEK2 codes for a kinase that is a key component of the DNA damage-signaling pathway. CHEK2 pathogenic variants were previously associated with breast and colorectal families and also with Li-Fraumeni phenotypes. Next generation sequencing (NGS) allowed for systematic inclusion of CHEK2 into gene panels. In here, we characterize the growing subgroup of CHECK2 BC families identified through our multidisciplinary program.

METHODS: Identification and review of CHEK2 families identified between 01/2000-06/2018 (until 2014 only the c.1100delC was tested (MLPA, MRC Holland); since 2014 NGS methods used were either,Trusight Cancer sequencing panel (Illumina, San Diego, CA, USA) or BRCA MASTR Dx (Multiplicom, Niel, Belgium). Carriers were included in a prospective follow up program.

RESULTS: 3646 index pts consented on gene testing. Most hereditary families (HF) were BRCA1/2 (374) (92%) but among non-BRCA HF bigger subgroups were 16 CHEK2, 10 Tp53 and 5 PALB2 HF. All CHEK2 index pts were diagnosed with only 3 different pathogenic variants: c.1100delC (9) c.319+2T&gt;A (6) and c.593-1G&gt;T (1 case of the only male BC pt in all CHEK2 pedigrees).

Index pts: mostly (93,8%) to females, with a mean age at first cancer diagnosis of 39 years (yrs) (30-52), 62,5% between 30-39yrs. With the exception of a Non Hodgking's Lymphoma index case, all index pts had BC(93,8%), 68,8% of which were ductal carcinomas and 12,5% of intraductal, all strongly positive for the estrogen receptor. With a mean follow up of 8,26yrs (3-15), secondary cancer cases occurred in 37,5% of index pts (mostly, 12,5%, BC at a mean of 53yrs (41-59).

Family phenotypes: data form 98 relatives (53,5% females) revealed diagnoses of BC (31,6%), prostate (8,1%), colorectal (7,1%) cancers. Only 22,2% of family cancers were diagnosed before 50yrs.

VUS: Among several complex variants of unknown significance, c.1036C&gt;T;p.Arg346Cys co-segregates in a predominantly male family with 3 prostate, 1 male and 1 female BC.

DISCUSSION AND CONCLUSIONS:

In the Portuguese population, emerging recurrent pathogenic variants in the CHEK2 gene, make it the most important non-BRCA BC gene so far. Carriers are included in prospective follow up but non-CHEK2 relatives are a challenge to genetic testing, as well as pedigree review, that questions its classification as a medium penetrance gene (or suggest the role of modifier factors).

Citation Format: Gomes VL, Machado P, Fragoso S, Santos S, Coelho I, Parreira J, Rodrigues P, Rodrigues F, Clara A, Bento S, Luís A, Opinião A, Vaz F. CHEK2: the third susceptibility BReast CAncer (BC) gene? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-09.

[High-dose magnesium sulfate in the treatment of aconite poisoning]

This article reports the case of a 62-year-old male patient who ingested the roots of Monkshood (Aconitum napellus) and white hellebore (Veratrum album) dissolved in alcohol with a suicidal intention and suffered cardiotoxic and neurotoxic symptoms. After contacting the Poison Information Centre ventricular arrhythmia was treated with high-dose magnesium sulphate as the only antiarrhythmic agent and subsequently a stable sinus rhythm could be established after approximately 3 h. Aconitum napellus is considered the most poisonous plant in Europe and it is found in gardens, the Alps and the Highlands. Poisoning is mainly caused by the alkaloid aconite that leads to persistent opening and activation of voltage-dependent sodium channels resulting in severe cardiac and neurological toxicity. As no specific antidote is known so far, poisoning is associated with a high mortality. The therapy with high-dose magnesium sulphate is based on in vitro and animal experiments as well as limited clinical case reports.

Influenza-associated Hospitalizations and Deaths, Costa Rica, 2009-2012

Data needed to guide influenza vaccine policies are lacking in tropical countries. We multiplied the number of severe acute respiratory infections by the proportion testing positive for influenza. There were ≈6,699 influenza hospitalizations and 803 deaths in Costa Rica during 2009-2012, supporting continuation of a national influenza vaccine program.

Distribution of genes encoding the trypsin-dependent lantibiotic ruminococcin A among bacteria isolated from human fecal microbiota

Fourteen bacterial strains capable of producing a trypsin-dependent antimicrobial substance active against Clostridium perfringens were isolated from human fecal samples of various origins (from healthy adults and children, as well as from adults with chronic pouchitis). Identification of these strains showed that they belonged to Ruminococcus gnavus, Clostridium nexile, and Ruminococcus hansenii species or to new operational taxonomic units, all from the Clostridium coccoides phylogenetic group. In hybridization experiments with a probe specific for the structural gene encoding the trypsin-dependent lantibiotic ruminococcin A (RumA) produced by R. gnavus, seven strains gave a positive response. All of them harbored three highly conserved copies of rumA-like genes. The deduced peptide sequence was identical to or showed one amino acid difference from the hypothetical precursor of RumA. Our results indicate that the rumA-like genes have been disseminated among R. gnavus and phylogenetically related strains that can make up a significant part of the human fecal microbiota.

Costs and benefits of high mutation rates: adaptive evolution of bacteria in the mouse gut

We have shown that bacterial mutation rates change during the experimental colonization of the mouse gut. A high mutation rate was initially beneficial because it allowed faster adaptation, but this benefit disappeared once adaptation was achieved. Mutator bacteria accumulated mutations that, although neutral in the mouse gut, are often deleterious in secondary environments. Consistently, the competitiveness of mutator bacteria is reduced during transmission to and re-colonization of similar hosts. The short-term advantages and long-term disadvantages of mutator bacteria could account for their frequency in nature.

Screening for carotid and renal artery stenoses in patients with aortoiliac disease

Patients with severe stenoses of the carotid and renal arteries define a population at high risk but most of them are asymptomatic. Here arises the question of who must be tested and what would be the actual utility of a screening program in the general or selected populations. The aim of this study was to assess the efficacy of a duplex-based screening for carotid and renal arteries stenoses, in a subset of patients with aortoiliac arterial disease, in terms of: (1) prevalence of occlusive disease of the carotid and renal arteries detected and surgical procedures generated; (2) analysis of clinical variables that could be useful to increase the suspicion index for the disease; and (3) predictive values of duplex scanning adjusted for the observed prevalence. One hundred sixty eight consecutive patients selected for elective aortoiliac surgery were included. Carotid duplex scanning, renal duplex scanning and/or aortorenal angiography, and recording of clinical predictive variables were obtained in all the patients. The statistical analysis included prevalence rates, multivariate analysis, and predictive values of carotid and renal duplex scanning adjusted for the observed prevalence. Greater than 50% asymptomatic stenosis in at least one of the internal carotid arteries (CAS > 50%) was detected in 47 (28%) patients [95% confidence interval (CI): 21.2%-34.8%]; 67 (39.9%) patients showed greater than 60% stenosis in one or both renal arteries (RAS > 60%) (95% CI: 32.5%-47.3%). Based on current surgical indications, carotid endarterectomy was performed in 24 (14.3%) patients and a bypass to the renal artery in 30 (17.8%) patients. Logistic regression analysis accepted the following variables, in this order: carotid bruit, age, and ankle/brachial index for predicting carotid artery stenosis; and hypertension and CAS for predicting renal artery stenosis. Based on previous validation studies of duplex scanning accuracy, estimated positive predictive values for significant stenosis of the carotid and renal arteries showed a range of 80.5%-89.1% and 82.3%-89.7%, respectively. Routine screening of the carotid and renal arteries may be justified in those patients with aortoiliac aneurysmal and occlusive disease, provided there is a high prevalence of clinically significant lesions and sufficient predictive values of duplex scanning are obtained.

The image of the psychiatrist in motion pictures

The psychiatrists who appear in commercial films can roughly be divided into 3 stereotyped categories: 1. The funny and foolish character who lacks all common sense. He often is more deranged than his patients, but in a harmless way. 2. The intelligent, attractive, modest, warm, etc. psychiatrist who devotes his time and life to the well-being of his patients. He is too perfect to be true and is usually a rather boring character. 3. The thoroughly evil psychiatrist, who abuses his power for his personal ambition or enrichment. He endangers the health and life of his patients with his outrageous treatments and experiments. He is a classical horror movie character. Some of the implications that these prejudiced representations in popular culture have on the doctor-patient relationship will be discussed.

[Epidemiological study of psychiatric and psychosocial emergencies at the University Hospital of the Free University in Brussels (AZ-VUB)]

This epidemiological study in a psychiatric emergency ward demonstrates the existence of a population in Psychosocial Crisis. An operational definition of Psychosocial Crisis is proposed on the basis of psychopathological and psychosocial scales. Suicide attempts are extremely frequent in this population. It appears to be very difficult to bring a prospective study in an emergency ward to a successful conclusion.

Inhibitory effect of dietary soybean meal on the establishment of a Clostridium strain in the gastrointestinal tract of mice

The presence of soybean meal in the diet of gnotobiotic mice was shown to prevent the establishment of a clostridial strain in the gastrointestinal tract. Soybean meal did not inhibit the growth of Clostridium in vitro, suggesting that the host plays a role in the observed inhibition of bacterial growth. The inhibitory factor in the soybean meal contains at least two components.

Remanent effect of some dietary regimens on the establishment of two Clostridium strains in the digestive tract of gnotobiotic mice

Axenic mice and rats fed different diets were associated only with two strains of Clostridium. The first one identified as Clostridium perenne was isolated from the fecal dominant flora of an adult rat. The second one belonging to the group I of Clostridium was isolated from the dominant flora of the feces from a piglet. Both strains were capable of becoming established in the digestive tract of animals fed dietary regimens called "permissive", while they did not become established in animals fed "nonpermissive" diets. However, when these bacterial strains had become established in animals fed a permissive diet, they persisted in the dominant flora even if the permissive diet was replaced by the nonpermissive one. This phenomenon was called remanent effect of the diet. It disappeared after 103 days for C. perenne, but not for the other Clostridium strain. This effect was not due to a selection of a genetic variant from the original strain or to a durable change in some characteristics of the host-animal associated with the bacterial strain.