Bacillus clausii therapy to reduce side-effects of anti-helicobacter pylori treatment: randomized, double-blind, placebo controlled trial
Aliment Pharmacol Ther 2004; 20: 1181–1188.
Bacillus clausii therapy to reduce side-effects of anti-Helicobacterpylori treatment: randomized, double-blind, placebo controlled trial
E . C . N I S T A * , M . C A N D E L L I * , F . C R E M O N I N I * , I . A . C A Z Z A T O * , M . A . Z O C C O * , F . F R A N C E S C H I * ,G . C A M M A R O T A * , G . G A S B A R R I N I * & A G A S B A R R I N I Departments of *Internal Medicine and Medical Pathology, Catholic University, Rome, Italy
Accepted for publication 27 September 2004
treatment. (ii) The same 7 days triple therapy and
placebo t.d.s. for 14 days starting from the first day of
Background: Helicobacter pylori eradication fails in
treatment. Side-effects were assessed using a validated
about 10% of patients, particularly because of the
questionnaire and were recorded for 4 weeks from the
occurrence of resistance to antibiotics and side-effects.
During anti-H. pylori therapy, probiotics have been
Results: The incidences of nausea, diarrhoea and
successfully used to reduce the incidence of side-
epigastric pain in patients treated with B. clausii were
significantly lower than in placebo group, in both PP
Aim: To evaluate the effect of Bacillus clausii, a probiotic,
and ITT analysis. Equally, intensity of nausea and
on incidence (primary variable) and severity of antibi-
diarrhoea in patients treated with B. clausii was
otic-associated side-effects during anti-H. pylori therapy.
significantly lower than in placebo group. There were
Methods: One hundred and twenty H. pylori-positive
no differences in adherence to treatment and H. pylori
patients were randomly screened to receive: (i) a
standard 7 days triple therapy with rabeprazole 20 mg
Conclusion: In symptom-free, H. pylori-positive subjects
b.d., clarithromycin 500 mg b.d. and amoxicillin 1 g
B. clausii bacteriotherapy reduces the incidence of the
b.d. and B. clausii t.d.s. (each preparation containing
most common side-effects related to anti-H. pylori
2 · 109 spores) for 14 days starting from the first day of
antibiotic therapy compared with placebo.
ation and failure to eradicate H. pylori. Poor compliance
to treatment is one of the determinants of failure to
Therapeutic schemes to eradicate Helicobacter pylori
eradicate H. pylori. Despite the number of dropouts is
infection are based on the association of antibiotics and
relatively small in clinical trials, this may not be the case
a proton pump inhibitor.1–8 Treatment outcome depends
on the class of antibiotic administered, dosages used,
Probiotics are defined as microbial cell preparations or
therapy duration, bacterial resistance and patients’
components of microbial cells that can beneficially impact
compliance. Gastrointestinal side-effects during antibi-
human health.9 The use of probiotics has recently been
otic therapy include diarrhoea, nausea, taste distortion,
proposed to increase patients’ tolerability by limiting side-
stomatitis and bloating. These side-effects reduce treat-
effects of anti-H. pylori eradicating therapies.10–12
ment tolerability and may cause treatment discontinu-
The probiotic strains previously used in H. pylori
eradication trials include Lactobacillus GG, Saccharomy-
Correspondence to: Prof. A. Gasbarrini, Department of Internal Medicine,
ces boulardii, or combinations of different strains. In
Catholic University, Rome, Italy. E-mail: [email protected]
these studies, the addition of probiotics improved the
tolerability of eradication regimens, with limited effect
– Sixty patients (male/female 33/27, mean age 46.2 ±
12.83) were randomly assigned to receive a triple
Bacillus clausii is a probiotic widely used in Italy since the
therapy based on clarithromycin 500 mg b.d.,
1960s for viral diarrhoea in children and for antibiotic
amoxicillin 1 g b.d., rabeprazole 20 mg b.d. for
related side-effects.13 B. clausii spores can survive the
7 days plus a probiotic preparation, one vial t.d.s.
gastric pH, activate and reach the intestinal tract where
(each vial containing 2 · 109 spores of B. clausii,
they germinate to vegetative forms.14, 15 Experimental
Enterogermina, Sanofi–Synthelabo OTC, Milan, Italy)
data suggest that both B. clausii spores and cells can
for 14 days, during eradication therapy and 1 week
adhere to the bowel wall and colonize the mucosa.16
Our aim was to assess, in a double-blind, randomized,
– Sixty patients (male/female 25/35, mean age 43.1 ±
placebo-controlled trial the effect of oral bacteriotherapy
13.36) were randomly assigned to a placebo pre-
with B. clausii on gastrointestinal side-effects occurring
paration, one placebo vial t.d.s., during the 7-day
eradication therapy and for 1 week thereafter. Theplacebo preparation, looked identical in colour, size,shape, weight and taste to the probiotic preparation.
The study was a single centre, double-blind, prospective,
Each patient was required to complete a validated daily
randomized, placebo controlled study performed at the
diary for 4 weeks, starting from the first day of the
Gastroenterology and Internal Medicine Day Hospital of
eradicating treatment.11 The diary contains a question-
Gemelli Hospital of Rome, Italy. One hundred and twenty
naire (slightly modified from DeBoer et al.) 17 evaluating
consecutive H. pylori-positive patients free from gastro-
onset, intensity and frequency of gastrointestinal side-
intestinal symptoms (spouses or relatives of patients with
effects: taste distortion, loss of appetite, nausea, vomit-
H. pylori associated gastrointestinal diseases who asked to
ing, epigastric pain, bloating, diarrhoea, constipation
be tested and treated for H. pylori infection) were enrolled
and skin rash. The intensity of symptoms was rated
using a scale, in which 0, 1, 2 and 3, respectively
Patients were considered eligible to enter the study if
corresponded to absent, mild, moderate and severe
they were between 18 and 65 years old, free of
symptoms. An overall judgment of tolerability was
gastrointestinal symptoms in the previous 3 months
assessed by the patient at the end of both the first and
and affected by gastric H. pylori infection as confirmed
second weeks of treatment. Treatment tolerability was
by a 13C-urea breath test. Exclusion criteria were: recent
scored with a scale in which 1, 2, 3, 4 and 5
(within the previous 3 months) use of anti-microbial
respectively corresponded to 1, no side-effect observed;
agents, bismuth compounds, proton pump inhibitors
2, mild side-effect(s), non-interfering with daily activit-
and H2 receptor antagonists, laxatives, anti-diarrhoeals,
ies; 3, moderate side-effect(s), slightly interfering with
other probiotic preparations, alcohol or illicit drug
daily activities; 4, severe side-effect(s), interfering with
abuse. Patients with acute or chronic gastrointestinal
daily activities but not leading to treatment interruption
diseases, or with major concomitant diseases including
and 5, severe side-effect(s), producing treatment inter-
psychiatric disorders and pregnant or lactating women
ruption. Adherence to treatment was evaluated by
were also excluded from the study. Patients under
counting the vials returned by the subject [patients who
chronic drug treatment were considered suitable if they
returned <80% of empty vials were not included in the
had been receiving such treatments for >3 months. All
‘per protocol population’ (PP) analysis].
patients signed a written informed consent.
Helicobacter pylori eradication was evaluated by means
Using a permuted blocks randomization (1:1), 120
of a 13C-urea breath 6 weeks after the end of the
patients were assigned to one of the following parallel
treatment. A delta 13C over baseline value higher than
3.5 was considered positive for active H. pylori infection.
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
B . C L A U S I I B A C T E R I O T H E R AP Y A N D S I D E - E F F E C T S O F H . P Y L O R I T H E R A P Y
Table 1. Demographic data of the patients included in the safetypopulation (n ¼ 114)
For statistical analysis the following population wereconsidered:
patients who have taken at least one dose of study
– ‘Intention-to-treat population’ (ITT), defined as all
randomized patients who have taken at least one
in age and baseline symptom scores (all patients were
dose of study treatment and have returned the first
symptom free at enrolments) between the placebo
diary, reporting at least one symptom assessment
and the B. clausii groups. On the contrary, a higher
during the 7-day eradication therapy. Missing data
prevalence of male gender was observed in B. clausii
because of premature discontinuation of treatment
group and female gender in placebo group.
were considered treatment failures for the analysisof symptom incidence and were replaced using
Trial flow. Six patients (three in the B. clausii group,
the mean of the available daily scores of the
three in the placebo group) did not start the assigned
patient for the analysis of symptoms intensity and
treatment. Eight patients (three in the B. clausii group,
five in the placebo group) did not return the first diary.
– ‘Per protocol population’, defined as all randomized
Further six patients (four in the B. clausii group, two in
patients who completed the study without protocol
the placebo group) were not included in the per-
protocol analysis because they did not return the
Descriptive analysis of demographic, anamnestic and
second diary or because of withdrawal or poor
clinical data by treatment was performed. Dichotomous
compliance (i.e. <80% of the vials were recovered)
variables were analysed by v2 test and relative risk (RR)
and its 95% confidence interval (CI) were calculated.
The H. pylori eradication rate was similar between
The differences between the two groups in symptoms
B. clausii and placebo groups. In particular, ITT analysis
intensity, summarized in the overall mean over time,
has shown H. pylori was eradicated in 39 of 54 patients
were assessed using analysis of variance, after rank
(72.2%) in the B. clausii group and in 37 of 52 patients
transformation of the summary measure, considering
(71.15%) in the placebo group. In PP population,
treatment and diary mean factors and treatment by
H. pylori was eradicated in 39 of 50 patients (78%) in
time interaction. For the overall judgements of tolerab-
the B. clausii group and in 37 of 50 patients (74%) in
ility, the distribution of patients with side-effects in the
two treatment groups was evaluated by Kruskal–Wallistest. Tests were two sided and P-value <0.05 was
Effect of Bacillus clausii on the incidence and intensity of
considered statistically significant.
side-effects. Both ITT and PP analysis showed a signifi-cant difference between the two treatments in theincidence of nausea, diarrhoea and epigastric pain. In
the ITT analysis, RR of occurrence of nausea were halved
Based on a previous study,9 a total sample size of 120
in patients treated with B. clausii compared with placebo
was calculated as adequate to detect, with an 80%
after one (RR ¼ 0.5; 95% CI 0.31–0.88) and 2 weeks
power and a two sided 5% significance level, a difference
(RR ¼ 0.45; 95% CI 0.21–0.96) of bacteriotherapy. A
between the two groups ‡20% in occurrence of nausea,
greater reduction in the risk of diarrhoea was observed in
the B. clausii group compared with the placebo groupafter one (RR ¼ 0.30; 95% CI 0.12–0.76) and 2 weeks(RR ¼ 0.38; 95% CI 0.08–1.9). For epigastric pain, after
1 week, the relative risk was 0.68, 95% CI 0.48–0.97
Baseline characteristics. Participant characteristics are
(Table 2). The incidence of vomiting, constipation and
showed in Table 1. There were no significant differences
skin rash were also lower in the B. clausii group
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
Randomized n = 120 Safety population n = 114 ITT population n = 106 PP population n = 100
compared with the placebo group, although the differ-
The individual patients’ overall assessment of tolerab-
ences were not statistically significant.
ility in ITT population was better in the group treated
The mean intensities and frequencies of nausea and
with B. clausii than in the placebo group. The difference
diarrhoea were also significantly lower in the B. clausii
was statistically significant after 2 weeks of treatment
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
B . C L A U S I I B A C T E R I O T H E R AP Y A N D S I D E - E F F E C T S O F H . P Y L O R I T H E R A P Y
Table 2. Incidence of symptoms during treatment. Data are presented as percentages and relative risks with 95% confidence intervals
RR, relative risks; CI, confidence intervals; PP, per protocol population; ITT, intention-to-treat population. * P < 0.05, **P < 0.01.
probiotic treatments during anti-H. pylori regimens
(PPI, clarithromycin and tinidazole) were able to reduce
In the present study, we report that patients using
the incidence diarrhoea, nausea and taste distortion. In
B. clausii during H. pylori eradication therapy experienced
the current study, amoxicillin was used instead of
a lower incidence of side-effects than subjects whose
tinidazole for the first time based on the Maastricht
regimen was supplemented with placebo. The symptoms
2–2000 Consensus guidelines.6 The different antibiotic
with a lower incidence in the group of patients treated
administered could explain the low incidence of taste
with B. clausii compared with those supplemented with
distortion experienced by patients in our study as taste
placebo were diarrhoea, nausea and epigastric pain.
distortion is one of the commonest side-effects related to
The differences were more marked in the first week of
use of tinidazole and other nitroimidazoles.
treatment when antibiotics were given and when the
Antibiotic related side-effects are common and usually
incidence of side-effects was higher in both groups. The
affect the gastrointestinal system. The bowel milieu is
incidence of nausea, diarrhoea and epigastric pain was
characterized by a high bacterial concentration, up to
affected by B. clausii treatment, in particular with regard
1012–1014 CFU/mL in the colon; such bacteria coexist
to the intensity and frequency of diarrhoea as it was
in equilibrium with colonic mucosal cells. Antibacterial
significantly lower in the probiotic treated group than
drugs can alter this equilibrium causing potentially
the placebo group. In previous studies,9, 11 oral
pathogen species to prevail over the normal resident
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
Table 3. Summary measure of symptoms intensity and frequency
PP, per protocol population; ITT, intention-to-treat population.
Table 4. Overall judgment on tolerability by time and treatment
microflora. Modifications in the composition of the
(intention-to-treat population population)
intestinal bacteria may be induced by any antibiotic, butthe broad spectrum antibiotics (such as tetracyclines,
aminoglycosides, macrolides and penicillins) are con-
sidered the most frequent drugs responsible for these
gastrointestinal side-effects. Moreover, macrolide anti-
biotics, such as clarithromycin, have been related to
increased contractility of gastrointestinal smooth mus-
cle, which may lead to increased motility and acceler-
Probiotics can also modify gut microflora. The probi-
otic species most commonly used include spore formers,
lactic acid bacteria and yeasts. Probiotics have been
shown to be useful and effective in a number ofgastrointestinal diseases such as antibiotic-associated
Kruskal–Wallis test: P ¼ 0.07 during the first week, P < 0.05 during
diarrhoea19 and inflammatory bowel diseases.20 The
the second week. * For two patients data are not available.
explanations for the effects of probiotics in human
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
B . C L A U S I I B A C T E R I O T H E R AP Y A N D S I D E - E F F E C T S O F H . P Y L O R I T H E R A P Y
disease include the synthesis of anti-microbial sub-
We anticipate that in dyspeptic patients the supplemen-
stances, the competition with pathogenic microorgan-
tation with B. clausii will reduce the burden of side-
isms for nutrients and microbial adhesion sites, the
effects to an extent that is more clinically relevant,
modification of toxins or toxin receptors, the incomplete
however, it must be acknowledged that these data were
lactose digestion and immune system modulation.21
not collected to prove this hypothesis. Thus an addi-
The use of B. clausii as a probiotic species has been
tional clinical study would be needed to prove this point.
based on more over than 40 years of clinical usage in
It should also be noted that we did not observe any
Italy with excellent tolerability and no report of side-
difference between two groups in the H. pylori eradica-
effects. Moreover it has several unique properties such
tion rate. This result is in agreement with previous
as the resistance to commonly used antibiotics, 22 the
studies with living probiotic species, 9, 11 and suggest
absence in normal resident intestinal flora and the
that B. clausii in the form and concentration we
sporogenic activity.13, 23–25 Bacillus clausii spores can
administered does not possess antibacterial activity
survive in the acid gastric environment, activate and
against H. pylori. Of relevance, in both arms we attained
reach the intestinal tract where they germinate to
eradication rates lower than in previous studies using
vegetative forms.14, 15 Yet, the actual mechanism of
the same antibiotic regimen.26 These results were
action of B. clausii spores in the restoration of intestinal
unexpected and might be partly attributable to the
flora has not been fully clarified. Experimental data
rising antibiotic resistance in our geographical area.
suggest that both B. clausii spores and cells can adhere
Resistance to clarithromycinin in Italy has been reported
to the bowel wall, allowing mucosal colonization.16 A
to be around 10%.27 Similar to previous experience 9, 11
previous study showed a positive action of the probiotic
overall compliance of patients was not affected by
in case of rotavirus diarrhoea and in children with
B. clausii. However, the sample size was chosen to
antibiotic-related gastrointestinal side-effects.13
evaluate difference in incidence of side-effects and not in
This study however has some limitations. First, the
eradication rate and overall compliance. Moreover,
occurrence of side-effects in anti-H. pylori therapy is
patients enrolled in this study asked to be eradicated.
mostly attributed to the use of antibiotics in moderate to
Thus, they might have been particularly motivated to
high doses and in combination. Although some specific
complete the treatment independently on the incidence
side-effects such as diarrhoea could be related to the
of side-effects. Although eradication rate and overall
disruption of gut microflora by antibiotics, the link with
compliance are not affected by B. clausii supplementa-
bowel microecology for other common side-effects such
tion, it is still be an advantage to reduce side-effects. On a
as nausea and epigastric pain is unproven. Until the
case-by-case basis, the clinician should determine whe-
mechanistic bases of the actions of probiotics are fully
ther it is worth supplementing the patient with B. clausii
understood, caution should be used in attributing
to prevent mild to moderate side-effects, without affect-
symptomatic benefits to probiotic oral therapy. Sec-
ing compliance. Cost consideration and the preference of
ondly, we did not perform stool assessment for bacterial
the individual patient should also be taken into account.
recovery. However, faecal recovery studies have previ-
In conclusion, this study shows that B. clausii treat-
ously confirmed presence of B. clausii in the stools after
ment during and after a standard seven day anti-
oral administration of commercially available prepara-
H. pylori regimen is associated with lower incidence of
tions and B. clausii has been shown to be resistant to the
self-reported side-effects and with a better tolerability to
antibiotics used in the present study. Thirdly, the results
multiple antibiotic treatment when compared with
from our study can be generalized only to subjects who
undergo antibiotic therapy without having gastrointes-tinal symptoms. In fact, we enrolled symptom-free
subjects who wished to eradicate their H. pyloriinfection, in order to assess newly occurring therapy-
1 Basset C, Holton J, Ricci C, et al. Review article: diagnosis and
related side-effects. The inclusion of symptom-free
treatment of Helicobacter: a 2002 updated review. AlimenPharmacol Ther 2003; 17: 89–97.
subjects allowed for clearer interpretation of the effect
2 Di Caro S, Assunta Zocco M, Cremonini F, et al. Levofloxacin
of supplementation with the probiotic on side-effects
based regimens for the eradication of Helicobacter pylori. Eur J
occurrence, but limited the effect size on symptom
Gastroenterol Hepatol 2002; 14: 1309–12.
intensity because the baseline scores were close to zero.
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
3 Gene E, Calvet X, Azagra R, Gisbert JP. Triple vs. quadruple
15 Urdaci MC, Bressollier P, Pinchuk I, Bacillus clausii probiotic
therapy for treating Helicobacter pylori infection: a meta-
strains: antimicrobial and immunomodulatory activities. J
analysis. Alimen Pharmacol Ther 2003; 17: 1137–43.
Clin Gastroenterol 2004; 38: S86–90.
4 Katelaris PH, Forbes GM, Talley NJ, Crotty B. A randomized
16 Angioi A, Zanetti S, Sanna A. Adhesiveness of Bacillus subtilis
comparison of quadruple and triple therapies for Helicobacter
strains to epithelial cells cultured in vitro. Microbial Ecology in
pylori eradication: the quadrate study. Gastroenterology
Health and Disease 1995; 8: 71–77.
17 de Boer WA, Thys JC, Borody TJ, Graham DY, O’Morain C,
5 Laine L, Hunt R, El-Zimaity H, Nguyen B, Osato M, Spenard J.
Tytgat GN. Proposal for use of a standard side effect scoring
Bismuth-based quadruple therapy using a single capsule of
system in studies exploring Helicobacter pylori treatment regi-
bismuth biskalcitrate, metronidazole, and tetracycline given
mens. Eur J Gastroenterol Hepatol 1996; 8: 641–3.
18 Peters DH, Clissold SP. Clarithromycin. A review of its anti-
clarithromycin for eradication of Helicobacter pylori in duode-
microbial activity, pharmacokinetic properties and therapeu-
nal ulcer patients: a prospective, randomized, multicenter,
tic potential. Drugs 1992; 44: 117–64.
North American trial. Am J Gastroenterol 2003; 98: 562–7.
19 Cremonini F, DiCaro S, Nista EC, et al. Meta-analysis: the effect
6 Malfertheiner P, Megraud F, O’Morain C, et al. Current con-
of probiotic administration on antibiotic-associated diarrhoea.
cepts in the management of Helicobacter pylori infection – the
Alimen Pharmacol Ther 2002; 16: 1461–7.
Maastricht 2–2000 Consensus Report. Alimen Pharmacol
20 Gionchetti P, Amadini C, Rizzello F, et al. Probiotics–role in
inflammatory bowel disease. Digestive & Liver Disease 2002;
7 Mascitelli L, Pezzetta F. Quadruple treatments for Helicobacter
pylori (comment). Lancet 2003; 361: 86.
21 Isolauri E. Probiotics in human disease. Am J Clin Nutr 2001;
8 Zullo A, Vaira D, Vakil N, et al. High eradication rates of
Helicobacter pylori with a new sequential treatment (erratum
22 Bozdogan B, Galopin S, Gerbaud G, Courvalin P, Leclercq R.
appears in Aliment Pharmacol Ther 2003 May 1;17:1205).
Chromosomal aadD2 encodes an aminoglycoside nucleot-
Alimen Pharmacol Ther 2003; 17: 719–26.
idyltransferase in Bacillus clausii. Antimicrob Agents Chemo-
9 Armuzzi A, Cremonini F, Bartolozzi F, et al. The effect of oral
administration of Lactobacillus GG on antibiotic-associated
23 Senesi S, Celandroni F, Tavanti A, Ghelardi E. Molecular
gastrointestinal side-effects during Helicobacter pylori eradica-
characterization and identification of Bacillus clausii Strains
tion therapy. Alimen Pharmacol Ther 2001; 15: 163–9.
marketed for use in oral bacteriotherapy. Applied & Environ-
10 Cremonini F, Canducci F, Di Caro S, et al. Helicobacter pylori
mental Microbiology 2001; 67: 834–9.
treatment: a role for probiotics? Dig Dis 2001; 19: 144–7.
24 Mazza P, Zani F, Martelli P. Studies on the antibiotic resistance
11 Cremonini F, Di Caro S, Covino M, et al. Effect of differ-
of Bacillus subtilis strains used in oral bacteriotherapy. Boll
ent probiotic preparations on anti-Helicobacter pylori ther-
apy-related side effects: a parallel group, triple blind,
25 Ciffo F. Determination of the spectrum of antibiotic resistance
placebo-controlled study. Am J Gastroenterol 2002; 97:
of the ‘Bacillus subtilis’ strains of Enterogermina. Chemioter-
12 Fuller R. Probiotics in human medicine. Gut 1991; 32: 439–
26 Danese S, Armuzzi A, Romano A, et al. Efficacy and tolerab-
ility of antibiotics in patients undergoing H. pylori eradication.
13 Benoni G, Marcer V, Cuzzolin L, Raimo F. Antibiotic admin-
Hepatogastroenterology 2001; 48: 465–7.
istration and oral bacterial therapy in infants. Chemioterapia
27 Franzin L, Pennazio L, Cabodi D, Rossigni F, Gioannini P.
Clarithromycin and amoxicillin susceptibility of Helicobacter
14 Ciffo F, Da Carro C, Giovannetti M. Gastric resistance of
pylori strains isolated from adults with gastric or duodenal
Bacillus subtilis spores used in oral bacteriotherapy: in vitro
ulcer in Italy. Curr Microbiol 2000; 40: 96–100.
studies. Farmaci e terapia 1987; 3: 163–169.
Ó 2004 Blackwell Publishing Ltd, Aliment Pharmacol Ther 20, 1181–1188
Links to Contents: Membership of professional organisations and societies Senate of Dental Specialties Formerly member on behalf of the British Society of Periodontology British Society of Periodontology 2001-2002: Scientific advisor to the president, Professor Francis Hughes European Association of Osseointegration Fellow of the International College of Dentists Senior Memb
Articles Highly drug-resistant Salmonella enterica serotype Kentucky ST198-X1: a microbiological study Simon Le Hello, Dorothée Harrois, Brahim Bouchrif, Lucile Sontag, Dalèle Elhani, Véronique Guibert, Khalid Zerouali, François-Xavier Weill Background Salmonella enterica is a major global food-borne pathogen, causing life-threatening infections. Published Online Ci