Évolution de la résistance aux antibiotiques de Pseudomonas aeruginosa dans un centre hospitalier universitaire entre 2002 et 2006

Aim of study

Monitor evolution of antibiotic resistance of Pseudomonas aeruginosa from 2002 to 2006 in our hospital to optimize antibiotherapy.

Patients and method

The infections/colonizations with P. aeruginosa have been identified by the hospital's informatic database. Bacteriological samples realized 48 hours after patient's admission was considered as nosocomial. A Cochran-Armitage test was conducted to assess the evolution of resistance.

Results

During this period, 2098 infections/colonizations with P. aeruginosa have been identified. Bacteriological samples (68.5%) were nosocomial. Among the β-lactam antibiotics, ceftazidime and imipenem were the most active (R = 16.8% and 15.2%, respectively), followed by piperacillin and piperacillin–tazobactam (R = 24.8%, 18.4%, respectively). Amikacin and tobramycin were more active than gentamicin (R = 19.9%; 22.2% and 40.6%, respectively). 28.9% of strains were resistant to ciprofloxacin. Nosocomial strains were significantly more resistant than non-hospital strains: ceftazidime: 17.9% versus 14.2%, p = 0.0346; ticarcillin–clavulanic acid: 47.5% versus 39.6%, p = 0.0009; piperacillin–tazobactam: 20.0% versus 14.8%, p = 0.0046; ciprofloxacin: 30.7% versus 25.2%, p = 0.0112. A significant increase in the resistance of nosocomial strains to ceftazidime, ticarcillin–clavulanic acid and piperacillin–tazobactam was noted. Resistance from non-hospital strains to fluoroquinolones, aminoglycosides, ceftazidime, piperacillin and ticarcillin–clavulanic acid decreased significantly.

Conclusion

P. aeruginosa is a predominantly nosocomial microorganism. There is a decrease of resistance for non-hospital strains. But the resistance of nosocomial strains to antibiotics widely prescribed in hospital is worrying.     

Membrane proteomes of Pseudomonas aeruginosa and Acinetobacter baumannii

Acinetobacter baumannii and Pseudomonas aeruginosa are known for their intrinsic resistance to antibiotics. Between mechanisms involved in this resistance, diminished expression of outer membrane proteins and up-regulation of efflux pumps play an important role. The characterization of membrane proteins is consequently necessary because of their importance in the antibiotic resistance but also in virulence. This review presents proteomic investigations aiming to describe the protein content of the membranes of these two bacterial species.     

Isolation and characterization of gallium resistant Pseudomonas aeruginosa mutants

Pseudomonas aeruginosa PA14 cells resistant to the novel antimicrobial gallium nitrate (Ga) were developed using transposon mutagenesis and by selecting spontaneous mutants. The mutants showing the highest growth in the presence of Ga were selected for further characterization. These mutants showed 4- to 12-fold higher Ga minimal inhibitory growth concentrations and a greater than 8-fold increase in the minimum biofilm eliminating Ga concentration. Both types of mutants produced Ga resistant biofilms whereas the formation of wild-type biofilms was strongly inhibited by Ga. The gene interrupted in the transposon mutant was hitA, which encodes a periplasmic iron binding protein that delivers Fe³⁺ to the HitB iron permease; complementation of the mutant with the hitA gene restored the Ga sensitivity. This hitA mutant showed a 14-fold decrease in Ga internalization versus the wild-type strain, indicating that the HitAB system is also involved in the Ga uptake. Ga uptake in the spontaneous mutant was also lower, although no mutations were found in the hitAB genes. Instead, this mutant harbored 64 non-silent mutations in several genes including those of the phenazine pyocyanin biosynthesis. The spontaneous mutant produced 2-fold higher pyocyanin basal levels than the wild-type; the addition of this phenazine to wild-type cultures protected them from the Ga bacteriostatic effect. The present data indicate that mutations affecting Ga transport and probably pyocyanin biosynthesis enable cells to develop resistance to Ga.     

Détection de la première souche de Staphylococcus aureus de sensibilité diminuée aux glycopeptides à l’hôpital la Rabta de Tunis

Since the advent of the first glycopeptide intermediately susceptible Staphylococcus aureus (GISA) and its heterogeneous variant hGISA in 1997, debate still ensues as their clinical significance. We report here the first case of GISA in Rabta hospital of Tunisia. Antimicrobial resistance was determined by the disk diffusion method in accordance with CA-SFM (Comity of Antibiogramm of French society of Microbiology). The MIC of vancomycin and teicoplanin was determined by E-test. The detection of mec A gene, virulence factors genes and agr groups (1-4) was performed by multiplex PCR. spa types were determined with the assistance of Ridom of Staph Type software (Ridom GmbH, Wurburg, Germany). The allelic profiles of MRSA were assigned on the basis of their MLST type using the eBURST program. A MRSA bacteraemia patient was treated with teicoplanin for 14 days. S. aureus isolated from patient's blood culture was identified as MRSA and GISA with teicoplanin MIC of 16 mg/l. The molecular study of this strain showed that it belongs to the clonal complex CC8 and is attached to the iberian clone (agr1, enterotoxin A, ST 247, spa type t052). Clinicians and laboratories alike are increasingly aware that patients on long-term vancomycin therapy may signal the presence and potential spread of hGISA/GISA strains. hGISA/GISA strains emerged from lineages with agr types I and II. The multiresitance of the Iberian clone ST247 could be explained by the presence of several resistance genes.     

Secretion of Pseudomonas aeruginosa type III cytotoxins is dependent on pseudomonas quinolone signal concentration

Pseudomonas aeruginosa is an opportunistic pathogen that can, like other bacterial species, exist in antimicrobial resistant sessile biofilms and as free-swimming, planktonic cells. Specific virulence factors are typically associated with each lifestyle and several two component response regulators have been shown to reciprocally regulate transition between biofilm-associated chronic, and free-swimming acute infections. Quorum sensing (QS) signal molecules belonging to the las and rhl systems are known to regulate virulence gene expression by P. aeruginosa. However the impact of a recently described family of novel quorum sensing signals produced by the Pseudomonas Quinolone Signal (PQS) biosynthetic pathway, on the transition between these modes of infection is less clear. Using clonal isolates from a patient developing ventilator-associated pneumonia, we demonstrated that clinical observations were mirrored by an in vitro temporal shift in isolate phenotype from a non-secreting, to a Type III cytotoxin secreting (TTSS) phenotype and further, that this phenotypic change was PQS-dependent. While intracellular type III cytotoxin levels were unaffected by PQS concentration, cytotoxin secretion was dependent on this signal molecule. Elevated PQS concentrations were associated with inhibition of cytotoxin secretion coincident with expression of virulence factors such as elastase and pyoverdin. In contrast, low concentrations or the inability to biosynthesize PQS resulted in a reversal of this phenotype. These data suggest that expression of specific P. aeruginosa virulence factors appears to be reciprocally regulated and that an additional level of PQS-dependent post-translational control, specifically governing type III cytotoxin secretion, exists in this species.     

Characterization of tail sheath protein of giant bacteriophage φKZ Pseudomonas aeruginosa

The tail sheath protein of giant bacteriophage φKZ Pseudomonas aeruginosa encoded by gene 29 was identified and its expression system was developed. Localization of the protein on the virion was confirmed by immunoelectron microscopy. Properties of gene product (gp) 29 were studied by electron microscopy, immunoblotting and limited trypsinolysis. Recombinant gp29 assembles into the regular tubular structures (polysheaths) of variable length. Trypsin digestion of gp29 within polysheaths or extended sheath of virion results in specific cleavage of the peptide bond between Arg135 and Asp136. However, this cleavage does not affect polymeric structure of polysheaths, sheaths and viral infectivity. Digestion by trypsin of the C-truncated gp29 mutant, lacking the ability to self-assemble, results in formation of a stable protease-resistant fragment. Although there is no sequence homology of φKZ proteins to proteins of other bacteriophages, some characteristic biochemical properties of gp29 revealed similarities to the tail sheath protein of bacteriophage T4.     

Enquête sur la perception de la gastro-entérite et de l’infection à Rotavirus par les mères en France

Aim

To describe the perception of the acute gastroenteritis (AGE) and the interest for the vaccination of the AGE due to Rotavirus.

Material and methods

Observational investigation realized by phone by the IPSOS institute, with 1002 French women of 18 years and more, constituting a representative national sample, having at least a child below 2 years, between 7 and January 31st, 2008.

Results

AGE is mainly considered by the mothers questioned as a grave pathology (43.1%) or very grave (51.3%) for the children below 2 years. This perception is bound to the symptoms and to the complications known for the disease. For the questioned mothers, the AGE comes along very often or often with diarrheas (97.2%), vomits (94.3%) or dehydration (94%). Hospitalizations are also perceived as frequent. The quasi-totality of the questioned women (98.3%) considers finally that it is about a very contagious disease (75.4%) or rather contagious (22.8%). The AGE at the child below 2 years provoke very frequently a medical consultation (91.8%), during which some solutions of oral rehydration are prescribed in six cases on 10 (62%). The questioned mothers are for the greater part favorable (86.3%) to a drinkable vaccine to prevent the AGE due to Rotavirus, and 88.1% say that they would intend to protect their child with this vaccine.

Conclusion

The questioned mothers know the potential gravity of the AGE and a very wide majority of them (86.3%) declare themselves favorable to the prevention of the AGE at Rotavirus by the vaccination.     

Importance de la PCR dans la gestion d’une épidémie à Mycoplasma pneumoniae au centre hospitalier de Béthune (Pas-de-Calais)

Subject

Molecular amplification (PCR) provides adequate rapid and specific diagnosis of Mycoplasma pneumoniae infection (first agent responsible for community-wide bacterial pneumonia in children above 5 years of age).

Method

Positive (Chlamylège^®, Argène) PCR in nasopharyngeal aspirate, respiratory samples and nasopharyngeal swab and/or positive serological test (ELISA).

Results

Diagnosis of M. pneumoniae infection in 39 cases: 31 between September and December 2008 (30 children and one adult) and eight since June 2009 (three adults and five children). Children (mean age: 3.6 years) were hospitalized in 88.6% of cases, mean hospitalization duration was 2.9 days for respiratory tract infections, mainly due to lack of response to β-lactamines therapy (65.7%). Four adults (mean age: 29.5 years) presented a pneumonia, with hospitalization for three of them with one in intensive care unit. Twenty-eight PCR have proved positive (87%): without associated serology (13), eight negative serologies, IgG and IgM positive (five), and IgG alone (two). Seven patients had only serological test for diagnosis: IgM ± IgG. For two children, IgM positive only in isolation, with a PCR probably false negative.

Conclusion

The sensitivity of the serology in the diagnosis of mycoplasma infection is limited: IgM, which appear traditionally 1 week after clinical signs are mostly inexistent for adults and IgG rise at a later stage. Early diagnosis of child pneumoniae by PCR helped rapidly characterize this epidemic phenomenon and adapt the treatment.     

Actualité de la résistance aux antibiotiques chez les bacilles à Gram négatif en Algérie

Antibiotic resistance has become a major public health problem in Algeria. Indeed the past decade, we have seen a significant increase in resistance to antibiotics especially in Gram-negative bacilli. Resistance to β-lactams in enterobacteria is dominated by the production of ESBL CTX-M-3 and CTX-M-15. The strains producing these enzymes are often the cause of potentially serious infections in both hospital and community settings. Identified plasmid cephalosporinases are CMY-2, CMY-12 and DHA-1. The isolation of strains of Enterobacteriaceae and Pseudomonas aeruginosa producing carbapenemases is rare in Algeria. Some Enterobacteriaceae producing OXA-48 or VIM-19 have been reported; so far, only VIM-2 has been identified in P. aeruginosa. However, the situation regarding the strains of Acinetobacter baumannii resistant to carbapenemases seems to be more disturbing. The carbapenemase OXA-23 is the most common and seems to be endemic in the north. The carbapenemase NDM-1 has also been identified. Resistance to aminoglycosides is marked by the identification armA gene associated with bla_CTX-M genes in strains of Salmonella sp. Several other resistance genes have been identified sporadically in strains of Enterobacteriaceae, P. aeruginosa and A. baumannii. Resistance genes to fluoroquinolones are more recent identification in Algeria. The most common are the Qnr determinants followed by the bifunctional enzyme AAC[6’]-Ib-cr. Resistance to sulfonamides and trimethoprim was also reported in Enterobacteriaceae strains in the west of the country.     

Persistent cystic fibrosis isolate Pseudomonas aeruginosa strain RP73 exhibits an under-acylated LPS structure responsible of its low inflammatory activity

Pseudomonas aeruginosa, the major pathogen involved in lethal infections in cystic fibrosis (CF) population, is able to cause permanent chronic infections that can persist over the years. This ability to chronic colonize CF airways is related to a series of adaptive bacterial changes involving the immunostimulant lipopolysaccharide (LPS) molecule. The structure of LPSs isolated from several P. aeruginosa strains showed conserved features that can undergo chemical changes during the establishment of the chronic infection. In the present paper, we report the elucidation of the structure and the biological activity of the R-LPS (lipooligosaccharide, LOS) isolated from the persistent CF isolate P. aeruginosa strain RP73, in order to give further insights in the adaptation mechanism of the pathogen in the CF environment. The complete structural analysis of P. aeruginosa RP73 LOS was achieved by chemical analyses, NMR spectroscopy and MALDI MS spectrometry, while the assessment of the biological activity was attained testing the in vivo pro-inflammatory capacity of the isolated LOS molecule. While a typical CF LPS is able to trigger a high immune response and production of pro-inflammatory molecules, this P. aeruginosa RP73 LOS showed to possess a low pro-inflammatory capacity. This was possible due to a singular chemical structure possessing an under-acylated lipid A very similar to the LPS of P. aeruginosa found in chronic lung diseases such as bronchiectstasis.     

Forte prévalence des infections communautaires et nosocomiales à Staphylococus aureus résistant à la méticilline et portant le gène de la leucocidine de Panton-Valentine dans l’Algérois

Objectives

To determine the prevalence of community acquired and hospital methicillin-resistant Staphylococcus aureus (S. aureus) infections and the Panton-Valentine leukocidin.

Patients and methods

Seven hundred S. aureus strains were collected during 21 months period in Mustapha Bacha hospital. Bacterial identification was based on standard methods and susceptibilities were tested by disk diffusion method. Molecular study (toxins, mecA gene and agr alleles) were determined for 221 S. aureus isolates by multiplex PCR.

Results

The global MRSA prevalence was 42 %, 35 % in the community and 49 % in hospital setting. The frequency of strains containing PVL genes (PVL+) was 36 %, their molecular profile was: agr3, mecA+, etd, edin, which correspond to the C-MRSA major ST80 clone in Europe and the Maghreb. The H-MRSA-PVL+ were multidrug resistant. Among the MSSA, 13 strains contained the tst gene and five contained the exfoliatine genes ETA and ETB.

Conclusion

Our results show a high rate of MRSA-PVL+ in the community and the hospital setting. The H-MRSA-PVL+ were multidrug resistant complicating their antibiotic treatment options.     

Polymorphisms in the lectin pathway genes as a possible cause of early chronic Pseudomonas aeruginosa colonization in cystic fibrosis patients

Genes of innate immunity may be involved in early onset of chronic Pa (Pseudomonas aeruginosa) colonization (cPaC) in cystic fibrosis (CF) patients.     

Évaluation des risques microbiologiques hydriques associés à Stenotrophomonas maltophilia et Pseudomonas aeruginosa au CHU d’Amiens

Background

Pseudomonas aeruginosa (Psa) and Stenotrophomonas maltophilia (Smalto) are major opportunistic waterborne pathogens causing hospital-acquired infections. This study aimed to assess the biocontamination level of cold water used in Amiens’ university hospital wards, from March to June 2008.

Methods

We cultivated 122 pairs of cold water first jet and taps cotton-swabs on Cetrimide agar for Psa, on Stenotrophomonas maltophilia selective medium with coloured indicator (SM2i) for Smalto, on Mueller Hinton agar used as isolation medium reference for both, 48 h at 30 °C. Data analysed with Épi-Info 6.04dFr were compared with chi² test, significant at p < .05.

Results

Psa and Smalto were isolated in 26.2 and 14.8% of water samples and in 21.3 and 10.7% of swab samples respectively. They were associated in 11.5% of water samples and 5% of swab samples. Psa was alone in 13.1% of water samples and 7.4% of swab samples whereas Smalto was found in 6.6% of water and 2.5% of swabs. Psa and Smalto were isolated from 14.8% of water samples and 8.2% of swab samples of the same tap. Finally, respectively 35.2 and 17.2% of the cold water taps were biocontaminated by Psa and Smalto. In fact, microbiologic water taps contamination risk was two-fold higher for Psa than for Smalto, p < .001, without variation between wards.

Conclusion

Sm2i and Cetrimide are suited and efficient medium respectively for Smalto and Psa isolation. Cold-water samples are sufficient for waterborne pathogens biocontamination risk appraisal. Our results urged healthcare workers on efficient water fittings microbiologic risk control to prevent healthcare associated waterborne infections, notably due to Psa and Smalto.     

Coinfection à Mycoplasma pneumoniae et Chlamydophila pneumoniae chez un enfant hospitalisé pour une pneumonie sévère avec détresse respiratoire : choix des outils diagnostiques pour une prise en charge optimale

The role for Mycoplasma pneumoniae and Chlamydophila pneumoniae in lower and upper respiratory tract infections in childhood increased by use of specialised diagnostic techniques, more and more performant for the early diagnosis of these infections. However, the prevalence of M. pneumoniae and C. pneumoniae as a cause of severe pneumoniae among hospitalized children has been rarely described. We report a case of M. pneumoniae et C. pneumoniae coinfection in a 10-year-old child hospitalized with a respiratory distress.     

Prévalence de Candida parapsilosis, C. orthopsilosis et de C. metapsilosis au sein des candidémies au CHU de Nantes et profil de sensibilité aux échinocandines par la méthode E-test : étude rétrospective de cinq ans (2004-2009)

Aim of the study

To determine the prevalence of C. parapsilosis sensu stricto, C. orthopsilosis and C. metapsilosis among candidemia at Nantes University Hospital and to evaluate the in vitro susceptibility of the isolates against three echinocandin drugs (caspofungin, micafungin and anidulafungin).

Material and methods

Retrospective study (march 2004 to july 2009) of 178 cases of candidemia corresponding to 183 Candida spp. strains identified by means of routine phenotypical methods. Re-identification of C. parapsilosis sensu lato isolates was performed by ITS rDNA sequencing analysis. Minimal inhibitory concentrations (MIC) were determined by E-test^®. All echinocandin non-susceptible isolates (MIC > 2 μg/mL) were analyzed for the presence/absence of FKS1 mutations associated with resistance.

Results

During this period, C. parapsilosis sensu lato was responsible for 27 candidemia, ranging at the second most common Candida species after C. albicans (n = 99, 54.1%). Neither isolates belong to C. orthopsilosis nor C. metapsilosis. According to the literature, all the isolates displayed high MICs against the three echinocandin drugs. All the isolates displayed both susceptibility (MIC ≤ 2 μg/mL) and a good agreement between MICs read at 24 h and 48 h for caspofungin and micafungin (MIC₅₀ = 0.75 μg/mL, MIC₉₀ = 1.5 μg/mL). Surprisingly, whereas most of the strains were susceptible to anidulafungin at 24 h (MIC₅₀ = 1 μg/mL, MIC₉₀ = 1.5 μg/mL), 14 (52 %) displayed non-susceptibility, despite the lack of mutation associated with resistance on FKS1, when reading was performed at 48 h (MIC₅₀ = 3 μg/mL, MIC₉₀ = 12 μg/mL).

Conclusion

Prevalence of C. orthopsilosis and C. metapsilosis in patients with candidemia is low at Nantes University Hospital. The difficulty encountered with MIC reading by E-test^® are discussed.     

Pneumocystose à Pneumocystis jiroveci : étude comparée de la PCR et des techniques de coloration

Diagnosis of pneumocystis pneumonia is usually based on clinical features and X-rays photography and confirmed in the laboratory by visualisation of Pneumocystis organisms in stained preparations of respiratory specimens using several techniques (Gomori-Grocott, May-Grünwald Giemsa, bleu de toluidine O). Actually, PCR has considerably increased sensitivity of detection of Pneumocystis. The aim of this study is to compare conventional PCR results to those of staining techniques (Gomori-Grocott, May-Grünwald Giemsa) in addition to the X-ray and clinical findings in order to evaluate the contribution of each method. Sixty-four respiratory specimens were collected from 54 immuno-compromised patients with clinical symptoms of pulmonary infection. We diagnosed pneumocystis pneumonia in 16 patients according to staining techniques and/or typical clinical and radiological findings and/or response to treatment. Of the 15 patients, 14 were positive by PCR and only five were positive by direct examination, yielding a sensitivity and specificity of 93,3 and 87,1% for PCR and 33,3 and 100% for staining techniques. Conventional PCR provides a sensitive and objective method for the detection Pneumocystis jiroveci from less invasive sample.     

Analyse immunoprotéomique comparative des sécrétomes de souches de Staphylococcus aureus et S. epidermidis chez les patients souffrant d’infections sur prothèses articulaires

Aim of the study

Staphylocci such as Staphylococcus aureus and S. epidermidis are the most frequently pathogens associated to prosthesis joint infections (PJI), counting for 75% among the isolated bacteria. In this study, we identified PJI-related antigens using two-dimensional immunoblots of S. aureus and S. epidermidis exoproteins probed with serum samples from patients with confirmed PJIs. We further analysed by ELISA tests the response of patients to the identified proteins.

Patients and methods

Secreted proteins from Mu50 strain (S. aureus) and RP62A strain (S. epidermidis) were separated by 2D gel electrophoresis and analyzed by western blot with serum samples from patients with confirmed S. aureus and S. epidermidis PJIs. Recombinant proteins corresponding to the identified proteins were expressed and screened with an in-house ELISA to evaluate their interest for the diagnosis of S. aureus and S. epidermidis PJIs.

Results

Fifty-two antigenic exoproteins were identified: 42 belonging to Mu50 strain, and 10 to RP62A strain. Twenty-two proteins were identified as S. aureus specific. Among these proteins, five were most frequently recognized by patients with S. aureus PJI.

Conclusion

Our results showed that few exoproteins were antigenic by RP62A strain compared to Mu50 strain. We identified five antigenic and S. aureus specific proteins, which may contribute to diagnosis, prevention and treatment of these infections.     

Évolution du nombre d’infections à Rotavirus et à virus respiratoire syncytial chez les enfants hospitalisés au CHU de Dijon entre 1998 et 2005

Aim

Respiratory syncytial virus (RSV) and Rotavirus infections represent up to 30% of cross infections in pediatric units. As they are a major public health problem, we studied their evolution and distribution at the Dijon University Hospital.

Population and methods

This exhaustive retrospective study included children under 15 with a new Rotavirus or RSV infection who were hospitalised at the Dijon University Hospital between 1998 and 2005. The general trend was determined by using moving averages, and the Spearman correlation coefficient r_s was calculated.

Results

From 1998 to 2005, 1886 new RSV (n = 981) or Rotavirus (n = 905) infections were identified in hospitalised children. The number of the infections decreased significantly, both for RSV (r_s = −0.71 ; p < 0.0001) and for Rotavirus (r_s = −0.77 ; p < 0.0001). Almost half of Rotavirus infections were nosocomial (46.3%) vs 5.3% of RSV infections, p < 0.0001. There was no significant difference in the proportion of RSV nosocomial infections between the epidemic and non-epidemic period (4.9% of nosocomial infections vs 7.1% respectively, p = 0.25). Rotavirus nosocomial infections were less frequent in epidemic period (41.6%) than in non-epidemic period (54.6%); p = 0.0002.

Conclusion

RSV and Rotavirus infections significantly decreased between 1998 and 2005. Proportion of RSV or Rotavirus infections didn’t increase in epidemic period, which could be explained both by an increased attention from healthcare professionals and by the effectiveness of hygiene measures taken.     

Apport de la PCR dans la recherche et l’identification des microsporidies intestinales chez les sujets infectés par le VIH

Aim

Intestinal microsporidiosis are among the most frequent opportunistic diseases in immunocompromised subjects. This study aimed to evaluate the contribution of PCR for a better detection and species identification of microsporidia in stool specimens of HIV-infected patients.

Patients and methods

Stool samples obtained from 119 HIV-infected Tunisian subjects were screened for intestinal microsporidiosis by light microscopy using Weber's modified Trichrome stain and by a PCR method using universal primers V1/PMP2 which amplified a common fragment of the small subunit rRNA gene of microsporidia. The obtained PCR products were then sequenced using an ABI PRISM 377 DNA sequencer.

Results

The results showed a better sensitivity of PCR in the detection of microsporidia with an infection rate of 14.3% significantly higher than that of 6.7% obtained by light microscopy (p = 0.03). As previously described, intestinal microsporidiosis was associated with low CD4 cell counts; 23.9% infection rate in patients having CD4 cell count under 200/mm³ against 5.6% in patients with higher CD4 cell count (p = 0.008). The sequencing of 15 out of the 17 positive PCR products has confirmed in all cases the species identified based on the PCR fragment size i.e., 250 pb for Enterocytozoon bieneusi (seven cases) and about 270 pb for Encephalitozoon intestinalis (nine cases); one case revealed a double infection.

Conclusion

PCR proved to be more effective than classical Trichrome stain for the diagnosis of intestinal microsporidiosis. Moreover, the ability of PCR to identify the species involved could also be useful for cases management.