BedBiopsy: diagnostic performance of bedside ultrasound-guided bone biopsies for the management of diabetic foot infection

OBJECTIVE

- We aimed to assess the feasibility and diagnostic performance of ultrasound-guided bone biopsies at the bedside of diabetic patients admitted for suspected foot osteitis not requiring surgery.

RESEARCH DESIGN AND METHODS

- In this retrospective monocentric study, we compared the performance of ultrasound-guided (n=29 consecutive patients, Dec.2020-Oct.2022) versus surgical (n=24 consecutive patients, Jan.2018-Nov.2020) bone biopsies at confirming or ruling out diabetic foot osteitis (primary outcome).

RESULTS

- Patient characteristics were similar in the two intervention groups, including arteritis prevalence (62.3%), SINBAD score, and wound location (phalanges 36%, metatarsus 43%, and calcaneus 21%). However, the ultrasound-guided group was older (67 ± 11 versus 60 ± 13 years respectively, P = 0.047) and had more type 2 diabetes (97% versus 75%, P = 0.038). Diagnostic performance (i.e., capacity to confirm or rule out suspected osteitis) was similar for ultrasound-guided (28/29 cases: 25 confirmations, 3 invalidations) and surgical (24 confirmations/24) biopsies, P = 0.358. No biopsy-related side effect or complication was observed for either intervention, even for patients on antiaggregation and/or anticoagulation therapy. The mean (± standard deviation) time necessary to perform the biopsy was shorter in the ultrasound-guided group (2.6 ± 3.0 versus 7.2 ± 5.8 days, respectively, P < 0.001) and wound evolution at three months was more favorable (83.3 versus 41.2%, P = 0.005) (94.4% versus 66.7%, respectively, patients with new surgical procedure within six months excluded; P = 0.055). Even though not statistically significant, healing rates in terms of wound and osteitis at six months were also better in the ultrasound-guided group (wound: 40.9% versus 36.8%; P = 0.790, and osteitis: 81.8 vs 55.6% P = 0.071).

CONCLUSION

- In diabetic patients with suspected foot osteitis not requiring surgery, bedside ultrasound-guided bone biopsies may constitute a promising alternative to surgical biopsies. This intervention provided excellent tolerance and microbiological documentation, short lead-times, and more favorable wound prognosis.

Early-Onset Infection Caused by Escherichia coli Sequence Type 1193 in Late Preterm and Full-Term Neonates

Using whole-genome sequencing, we characterized Escherichia coli strains causing early-onset sepsis (EOS) in 32 neonatal cases from a 2019-2021 prospective multicenter study in France and compared them to E. coli strains collected from vaginal swab specimens from women in third-trimester gestation. We observed no major differences in phylogenetic groups or virulence profiles between the 2 collections. However, sequence type (ST) analysis showed the presence of 6/32 (19%) ST1193 strains causing EOS, the same frequency as in the highly virulent clonal group ST95. Three ST1193 strains caused meningitis, and 3 harbored extended-spectrum β-lactamase. No ST1193 strains were isolated from vaginal swab specimens. Emerging ST1193 appears to be highly prevalent, virulent, and antimicrobial resistant in neonates. However, the physiopathology of EOS caused by ST1193 has not yet been elucidated. Clinicians should be aware of the possible presence of E. coli ST1193 in prenatal and neonatal contexts and provide appropriate monitoring and treatment.

Reassessing the Performance of the "Step-By-Step" Approach to Febrile Infants 90 Days of Age and Younger in the Context of the COVID-19 Pandemic: A Multicentric Retrospective Study

BACKGROUND

Infants with COVID-19 can often present with fever without source, which is a challenging situation in infants <90 days old. The "step-by-step" algorithm has been proposed to identify children at high risk of bacterial infection. In the context of the COVID-19 pandemic, we aimed to reassess the diagnostic performance of this algorithm.

METHODS

We performed a multicentric retrospective study in 3 French pediatric emergency departments between 2018 and 2020. We applied the "step-by-step" algorithm to 4 clinical entities: COVID-19, febrile urinary tract infections (FUTI), invasive bacterial infection (IBI), and enterovirus infections. The main outcome was the proportion of infants classified at high risk (ill-appearing, ≤21 days old, with leukocyturia or procalcitonin level ≥0.5 ng/mL).

RESULTS

Among the 199 infants included, 40 had isolated COVID-19, 25 had IBI, 60 had FUTI, and 74 had enterovirus infection. All but 1 infant with bacterial infection were classified at high risk (96% for IBI and 100% for FUTI) as well as 95% with enterovirus and 82% with COVID-19. Infants with COVID-19 were classified at high risk because an ill-appearance (72%), an age ≤21 days (27%), or leukocyturia (19%). All these infants had procalcitonin values <0.5 ng/mL and only 1 had C-reactive protein level >20 mg/L.

CONCLUSIONS

The "step-by-step" algorithm remains effective to identify infants with bacterial infection but misclassifies most infants with COVID-19 as at high risk of bacterial infection leading to unnecessary cares. An updated algorithm based adding viral testing may be needed to discriminate fever related to isolated COVID-19 in infants <90 days old.

Imported loiasis in France: a retrospective analysis of 167 cases with comparison between sub-Saharan and non sub-Saharan African patients

BACKGROUND

Imported loiasis is a rare cause of consultation at the return of stay in central Africa, which often poses difficult diagnostic and therapeutic questions to practitioners especially those who are unaccustomed to tropical medicine. These difficulties can lead to risks for the patients especially if inappropriate treatment is given. Large series of imported loiasis are scarce.

METHODS

We retrospectively studied the data including outcome in patients diagnosed with imported loiasis between 1993 and 2013 in the Paris area on the basis of a parasitological diagnosis (microfilaremia > 1/ml and/or serologic tests). We compared sub-Saharan and non sub-Saharan African patients.

RESULTS

Of the 177 identified cases, 167 could be analysed. Sex ratio was 1, mean age 41 years and 83% were sub-Saharan Africans. Cameroon was the main country of exposure (62%). Incubation time may be long (up to 18 months). Of the 167 cases, 57% presented with characteristic symptoms (Calabar swellings, creeping dermatitis, eyeworm) whereas 43% were diagnosed fortuitously. Microfilaremia was evidenced in 105 patients (63%), and specific antibodies in 53%. Compared to sub-Saharan Africans, other patients were presenting less frequently with eyeworm migration and microfilaremia whereas they had higher eosinophilia and positive serology. Prevalence of Calabar swellings was not significantly different between the two groups. Cure rates were 52% with ivermectin alone, and 77% with ivermectin followed by diethylcarbamazine. No severe adverse event was reported.

CONCLUSIONS

Presentation of imported loiasis varies according to ethnicity. A systematic screening should be recommended in patients with potential exposure in endemic country. Treatment with ivermectin followed by diethylcarbamazine could be a valuable option.

Multiplex PCR reveals a high prevalence of multiple pathogens in traveller's diarrhoea in children

OBJECTIVE

Traveller's diarrhoea (TD) is one of the most frequent illnesses affecting children returning from tropical countries. The purpose of this study was to assess the distribution of pathogens associated with TD in children using a multiplex PCR assay on stool samples.

DESIGN

All the children admitted for TD in two university hospitals from 1 August to 15October during 2014 and 2015 were included in a prospective study. Stool samples were tested by a multiplex PCR FilmArray GI panel detecting 22 pathogens. Performances for the detection of major enteropathogenic bacteria (Salmonella, Shigella and Campylobacter spp) by multiplex PCR and conventional culture methods were compared. The prevalence of extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae was also determined.

RESULTS

Fifty-nine children were included. In 58 cases (98%), at least one pathogen was identified, including 9 different enteropathogenic bacteria, 5 viruses and 2 parasites. Multiplex PCR enhanced the enteropathogenic bacteria detection by 25%. The most frequent pathogens were enteroaggregative Escherichia coli (n=32), enteropathogenic E. coli (n=26), enterotoxigenic E. coli (n=19), Salmonella enterica, enteroinvasive E. coli/Shigella (n=16 each), Cryptosporidium, sapovirus (n=11 each), Campylobacter jejuni, norovirus (n=10 each), rotavirus (n=9), Giardia (n=8) and Shiga-toxin-producing E. coli (n=4). Fifty-two coinfections were observed, notably including bacteria and viruses (n=21), multiple bacteria (n=14), or bacteria and parasites (n=10). ESBL were detected in 28 cases. Multiplex PCR could optimise the number of treated patients by 27% compared with stool cultures.

CONCLUSION

Multiplex PCR on stools revealed a high prevalence of diverse enteric pathogens and coinfections in children with TD. Major enteropathogenic bacteria were more frequently detected by multiplex PCR compared with conventional culture. Finally, this technique allows the start of appropriate and early antibiotic treatment and seems to optimise the number of correctly treated patients.

Carriage of ESBL-producing Enterobacteriaceae in French hospitals: the PORTABLSE study

BACKGROUND

Currently, contact precautions are recommended for patients colonized or infected with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Recent studies have challenged this strategy. This study aimed to assess the rate of ESBL-PE faecal carriage among hospitalized patients according to type of hospital ward, and to identify risk factors associated with carriage.

METHODS

A point prevalence study was conducted in five different types of hospital ward [medical, surgical, intensive care unit (ICU), after care and rehabilitation, and geriatric] in eight French hospitals. All patients included in the study provided a fresh stool sample.

RESULTS

In total, 554 patients were included in the study, with a median age of 73 years (range 60-82 years). The overall faecal carriage rate of ESBL-PE was 17.7%. The most frequently encountered species among ESBL-PE was Escherichia coli (71.4%), followed by Klebsiella pneumoniae (14.3%). Risk factors associated with ESBL-PE faecal carriage on univariate analysis were: living in the Paris region (P<0.01) and hospitalization on a geriatric ward (P<0.01). Interestingly, the cumulative duration of hospital stay before screening was not associated with a significantly higher prevalence of ESBL-PE carriage, regardless of ward type. The ESBL-PE colonization rate was much higher for patients hospitalized on geriatric wards (28.1%) and ICUs (21.7%) compared with those for patients hospitalized on surgical wards (14.8%), medical wards (12.8%) or aftercare and rehabilitation (11.2%).

CONCLUSION

The overall prevalence of ESBL-PE faecal carriage was 17.7%, with only 21% of patients identified previously as carriers. The delay between admission and screening was not associated with an increase in ESBL-PE faecal carriage.

Performance of rapid diagnostic tests for imported malaria in clinical practice: results of a national multicenter study

We compared the performance of four rapid diagnostic tests (RDTs) for imported malaria, and particularly Plasmodium falciparum infection, using thick and thin blood smears as the gold standard. All the tests are designed to detect at least one protein specific to P. falciparum (Plasmodium histidine-rich protein 2 (PfHRP2) or Plasmodium LDH (PfLDH)) and one pan-Plasmodium protein (aldolase or Plasmodium LDH (pLDH)). 1,311 consecutive patients presenting to 9 French hospitals with suspected malaria were included in this prospective study between April 2006 and September 2008. Blood smears revealed malaria parasites in 374 cases (29%). For the diagnosis of P. falciparum infection, the three tests detecting PfHRP2 showed high and similar sensitivity (96%), positive predictive value (PPV) (90%) and negative predictive value (NPV) (98%). The PfLDH test showed lower sensitivity (83%) and NPV (80%), despite good PPV (98%). For the diagnosis of non-falciparum species, the PPV and NPV of tests targeting pLDH or aldolase were 94-99% and 52-64%, respectively. PfHRP2-based RDTs are thus an acceptable alternative to routine microscopy for diagnosing P. falciparum malaria. However, as malaria may be misdiagnosed with RDTs, all negative results must be confirmed by the reference diagnostic method when clinical, biological or other factors are highly suggestive of malaria.

Longitudinal study assessing the return of chloroquine susceptibility of Plasmodium falciparum in isolates from travellers returning from West and Central Africa, 2000-2011

Background

Chloroquine (CQ) was the main malaria therapy worldwide from the 1940s until the 1990s. Following the emergence of CQ-resistant Plasmodium falciparum, most African countries discontinued the use of CQ, and now promote artemisinin-based combination therapy as the first-line treatment. This change was generally initiated during the last decade in West and Central Africa. The aim of this study is to describe the changes in CQ susceptibility in this African region, using travellers returning from this region as a sentinel system.

Methods

The study was conducted by the Malaria National Reference Centre, France. The database collated the pfcrtK76T molecular marker for CQ susceptibility and the in vitro response to CQ of parasites from travellers’ isolates returning from Senegal, Mali, Ivory Coast or Cameroon. As a proxy of drug pressure, data regarding CQ intake in febrile children were collated for the study period. Logistic regression models were used to detect trends in the proportions of CQ resistant isolates.

Results

A total of 2874 parasite isolates were genotyped between 2000–2011. The prevalence of the pfcrt76T mutant genotype significantly decreased for Senegal (from 78% to 47%), Ivory Coast (from 63% to 37%), Cameroon (from 90% to 59%) and remained stable for Mali. The geometric mean of the 50% inhibitory concentration (IC₅₀) of CQ in vitro susceptibility and the proportion of resistant isolates (defining resistance as an IC50 value > 100 nM) significantly decreased for Senegal (from 86 nM (59%) to 39 nM (25%)), Mali (from 84 nM (50%) to 51 nM (31%)), Ivory Coast (from 75 nM (59%) to 29 nM (16%)) and Cameroon (from 181 nM (75%) to 51 nM (37%)). Both analyses (molecular and in vitro susceptibility) were performed for the 2004–2011 period, after the four countries had officially discontinued CQ and showed an accelerated decline of the resistant isolates for the four countries. Meanwhile, CQ use among children significantly deceased in this region (fixed effects slope = −0.3, p < 10^-3).

Conclusions

An increase in CQ susceptibility following official withdrawal of the drug was observed in travellers returning from West and Central African countries. The same trends were observed for molecular and in vitro analysis between 2004-2011and they correlated to the decrease of the drug pressure.

Clostridium difficile carriage in healthy infants in the community: a potential reservoir for pathogenic strains

BACKGROUND

Clostridium difficile has long been considered to be a nosocomial pathogen but has emerged in the community in recent years. During infancy, asymptomatic C. difficile colonization is common. However, knowledge of colonization determinants and strain characteristics is limited. We studied the dynamics of C. difficile colonization in healthy infants from the community. Determinants of colonization and strain genotypes were also determined in a cohort of infants attending day nurseries.

METHODS

A 1-year follow-up study involving 10 healthy infants was performed to determine the incidence and kinetics of intestinal C. difficile colonization. In addition, a 1-point study involving 85 healthy infants (age, 0-3 years) from 2 day nurseries was performed. C. difficile isolates were typed by polymerase chain reaction-ribotyping and analyzed for the presence of toxin genes.

RESULTS

During the follow-up study, all infants acquired C. difficile and were colonized for several months. An early (neonatal) and a late (4-6 months of age) acquisition period were identified. In day nurseries, 38 infants (45%) carried C. difficile, with 11 (13%) carrying a toxigenic isolate. Age and several environmental factors were associated with the C. difficile carrier state. Strains causing disease in adults were identified in infants. Interestingly, no infant carried the common epidemic 027 or 078 strains.

CONCLUSIONS

This study provides information on the dynamics of colonization in infants in the community and on the genotype of involved strains. C. difficile colonization appears mainly as an age-dependent process. Pathogenic strains circulate in asymptomatic infants from the community, who represent a potential reservoir of pathogenic strains.

Comparison of commercial molecular assays for toxigenic Clostridium difficile detection in stools: BD GeneOhm Cdiff, XPert C. difficile and illumigene C. difficile

Three commercial molecular assays were evaluated for toxigenic Clostridium difficile detection in stools. As compared to toxigenic culture, BD GeneOhm Cdiff (BD Diagnostics), XPert C. difficile (Cepheid) and illumigene C. difficile (Meridian Bioscience) demonstrated respectively a sensitivity of 95.5%, 97.8% and 86.7% and a specificity of 97.9%, 97.9% and 100%.

Prevalence and diversity of Clostridium difficile strains in infants

During early infancy asymptomatic intestinal colonization by Clostridium difficile is frequent. To update information on infant colonization prevalence and to characterize infant strains, in terms of their virulence factors and their phylogenetic diversity, a prospective screening of C. difficile in the stools of infants 0 to 2 years old was conducted at Jean Verdier Hospital (Hôpital Jean Verdier) over an 18 month period. C. difficile was screened by toxigenic culture, and molecular characterization was performed by PCR-ribotyping and multilocus sequence typing (MLST). The overall C. difficile colonization prevalence was 33.7 % (99/294). The colonization rate by a toxigenic strain was 7.1 % (21/294). Community-acquired C. difficile accounted for 66.7 % (66/99) of cases. Molecular typing was performed on 90 isolates from Jean Verdier Hospital and 8 additional isolates from another hospital in Versailles (Centre Hospitalier de Versailles). Among these isolates, 23 were toxigenic (21 tcdA(+)/tcdB(+) and 2 tcdA(-)/tcdB(+)). All the isolates were negative for the binary toxin genes. Seventeen PCR ribotypes (PRs) were identified, with five PRs accounting for 82.7 % (81/98) of the isolates. MLST generated 15 different sequence types (STs). The predominant genotype, PRJV11-ST38 (33.7 %), included only non-toxigenic strains. Toxigenic strains were distributed in eight genotypes. Neither PR027-ST3, nor PR078/126-ST49 were identified but some PRs/STs corresponded to well-known adult infectious strains. These results indicate that infants are widely colonized by non-toxigenic strains. However, toxigenic adult infectious strains circulate in asymptomatic infants even in the community; thus, infants may be a reservoir for adult infectious strains.

Sudden death caused by Staphylococcus aureus carrying Panton-Valentine leukocidin gene in a young girl

Staphylococcus aureus carrying the Panton-Valentine leukocidin (PVL) gene could be the source of both recurrent furunculosis or abscesses and severe infections, mainly necrotising pneumonia. We present the case of a young girl from consanguineous parents who died suddenly. The postmortem examination revealed necrotising pneumonia due to a PVL producing Staphylococcus aureus strain, raising the question of the role of the host's immune status in this infection.

[Comparison of three Clostridium difficile culture media: interest of enhancing spore germination media?]

AIM

Clostridium difficile is the most common agent of postantibiotic and nosocomial bacterial diarrhoea. Since the emergence of the highly virulent and epidemic strain NAP1/027 in Europe, it appears necessary to isolate C. difficile strains to realize an epidemiologic follow-up by molecular typing. The aim of this work was to compare three selective culture conditions for the isolation of C. difficile.

METHODS

One hundred and thirty stools collected from patients hospitalized at Jean Verdier were swabbed on the commercial medium CLO (BioMérieux) and on a medium prepared at the laboratory (CCTa: Columbia, cefoxitine 8 mg/l, cycloserine 250 mg/l, horse blood 5 %, sodium taurocholate 0.1 %) with and without preliminary alcoholic shock (EtOH). C. difficile was isolated from 38 stools and colonies were counted on each medium.

RESULTS

The fluorescence intensity of C. difficile colonies is comparable on CLO and CCTa-EtOH media, however their aspect is more characteristic on CLO. This medium appears very selective contrary to the CCTa medium on which an associated flora obstructs the fluorescence reading and requires a new isolation of the suspect strains. On average 30 times more colonies of C. difficile are counted on CCTa+/-EtOH than on CLO, suggesting the presence of great proportions of spores in the stools.

CONCLUSIONS

The medium CLO is successful for the isolation of C. difficile despite of its selectivity. Nevertheless, it appears interesting to associate a medium enhancing spore germination as the CCTa medium inoculated after alcoholic shock to increase the sensitivity of detection while being freed from conservation and transport conditions.

New trends in Clostridium difficile virulence and pathogenesis

The disease spectrum caused by Clostridium difficile infection ranges from antibiotic-associated diarrhoea to life-threatening clinical manifestations such as pseudomembranous colitis. C. difficile infection is precipitated by antimicrobial therapy that causes a disruption of the normal colonic microbiota, predisposing to C. difficile intestinal colonisation. The pathogenicity of C. difficile is mediated by two exotoxins, TcdA and TcdB, both of which damage the human colonic mucosa and are potent cytotoxic enzymes. C. difficile must first be implanted in the gut and attach to epithelial cells, which are protected by a layer of dense mucus. Confirmed and putative accessory virulence factors that could play a role in adherence and intestinal colonisation have been identified and include proteolytic enzymes and adhesins. Recently, the epidemiology of C. difficile infection has radically changed and an increased incidence is associated with outbreaks in North America and Europe. Several reports suggest that disease severity is increasing to include sepsis syndrome and toxin megacolon. Elderly, debilitated patients in hospitals and nursing homes are particularly vulnerable. A hypervirulent, epidemic strain has been associated with the changing epidemiology and severity of disease. Here, we review the characteristics of the epidemic NAP1, PCR ribotype 027 C. difficile strain that could explain its hypervirulence and epidemic spread.

Activité in vitro de la moxifloxacine (8-méthoxyquinolone) seule ou en association avec le céfotaxime sur les streptocoques du groupe B

AIM OF THE STUDY

Our objective is to determine in vitro efficiency of moxifloxacin (MXF) alone or in combination with cefotaxime (CTX) on Group B streptococcus (GBS).

MATERIALS AND METHODS

For 21 strains of GBS isolated from newborn invasive infections (6 meningitis and 15 bacteraemia), the bacterial growth in Mueller Hinton broth with MXF and/or CTX leaded to the determination of MIC and MBC, the determination of tolerance for CTX and the evaluation of the bacteriostatic action of these antibiotics combination by calculating the FIC index. Time-kill studies were conducted for MXF and CTX alone or in combination for the first four hours, with concentrations likely reached in CSF.

RESULTS

Study of GBS growth with crossed concentrations of MXF and CTX showed no resistant strains, no tolerant strains, and no antagonism between MXF and CTX. Killing curves demonstrated that MXF is ten-fold more active than CTX in the first four hours.

DISCUSSION

MXF is an interesting antibiotic for its good activity on the GBS, suggesting that MXF is a good candidate for further evaluation in GBS meningitis in animal model.

Évaluation de l'antibiogramme par diffusion en milieu gélosé pour le dépistage de souches de Clostridium difficile de sensibilité diminuée aux antibiotiques

AIM

In vitro determination of Clostridium difficile susceptibility to antibiotics is not routinely performed. The aim of this study was to evaluate the performance of antibiotic susceptibility determination with the disk diffusion method for screening C. difficile isolates with decreased susceptibility to antibiotics.

METHODS

Thirty-six C. difficile isolates (toxigenic or not) isolated in 2005 and 2006 from three hospitals Assistance publique-Hôpitaux de Paris (Jean-Verdier, René-Muret, Beaujon) were studied by disk diffusion method with 14 antibiotics. Mueller-Hinton agar supplemented with sheep blood (Bio-Rad*) were swabbed with a C. difficile suspension at 1 McFarland. To check the results obtained with the disk diffusion method, Minimal Inhibitory Concentration (MIC) were performed respectively with E-test for glycopeptides and metronidazole and with the agar dilution reference method and E-test for new molecules with a potential activity against anaerobes: imipenem, ertapenem, linezolid and moxifloxacin.

RESULTS

The decreased susceptibility (resistant and intermediate) observed was 40% for amoxicillin-clavulanate, 60% for piperacillin-tazobactam, 100% for ceftriaxone, 81% for imipenem, 61% for ertapenem, 2% for chloramphenicol, 34% for erythromycin, 90% for lincomycin, 2% for linezolid, 98% for levofloxacin, 17% for moxifloxacin and 0% for vancomycin, teicoplanin and metronidazole. The results obtained with the disk diffusion method were compared to MICs obtained with E-test and reference method.

CONCLUSION

The disk diffusion method seems to be a good method to detect isolates suspected to have a decreased susceptibility and consequently to reduce MIC determinations.

Molecular characterization of Clostridium difficile clinical isolates in a geriatric hospital

The discriminatory potential of a combination of various typing methods was evaluated on a set of 21 Clostridium difficile isolates obtained from symptomatic patients hospitalized in a geriatric unit and 7 non-toxigenic isolates from the same hospital. Isolates were firstly serotyped and toxinotyped. Of the 28 isolates, 19 belonged to serogroup A. PCR-ribotyping and PCR-RFLP on the fliC and slpA genes were then applied to these 19 isolates. The results suggest that the combination of PCR-ribotyping with PCR-RFLP analysis of slpA could be more discriminatory and suitable for studying C. difficile epidemiology.

Report of a case of congenital malaria Plasmodium malariae in France

Congenital malaria (CM) has been considered to be rare, even in malaria-endemic areas but the disease can result in significant neonatal morbidity. Because of its rarity, the disease may go undiagnosed for a prolonged period in a seriously ill infant. We report the first case of Plasmodium malariae CM from a HIV mother. HIV could have facilitated the transfer of erythrocytic persistent P. malariae through the placenta to the fetus.

[Evaluation of four immunoenzymatic tests for detecting Clostridium difficile toxins A and B]

Four immunoenzymatic tests for detecting Clostridium difficile toxins A and B were studied: two rapid tests (Tox A/B QUIK CHEK-Techlab and NoviView Toxine-A-Hiss diagnostics) and two Elisa tests (C. difficile TOX A/B II -Techlab and Toxin A+B Elisa Test, Novitec-Hiss diagnostics). The results were compared to those obtained with ImmunoCard Tox A+B -ICTAB (Meridian), C. difficile Toxine A (Oxoid) for rapid test and Elisa Premier A+B Meridian for Elisa. A total of 41 stools and 16 isolates were studied with rapid tests. On stools, the sensitivity and specificity of QUIK CHEK test was 94.1% and 100% respectively compared to the test ICTAB. On the isolates, sensitivity and specificity was 100%. With the Noviview test, the sensitivity on stools and isolates was respectively 88.2 and 85.7% and the specificity was 100% compared to Oxoid. A total of 38 stools were studied with Elisa tests. With Techlab test compared to the test Premier, sensitivity and specificity was 100%. The Novitec test gave five false negative reactions with consequently a sensitivity of 70.6%.

[Congenital malaria as a result of Plasmodium malariae in an infant born to a HIV-seropositive woman]

Congenital malaria is uncommon in France. The purpose of this report is to describe a case involving a six-week-old infant who was hospitalized with fever, hepatosplenomegaly, anemia and thrombopenia. Thick and thin blood smears were positive for Plasmodium malariae. The infant responded favorably to chloroquine. Based on this experience, we performed a search of the literature to find case reports on congenital malaria in France and compare clinical and epidemiologic data with series reported in the United States and from endemic areas. The placenta appears to provide an effective barrier against Plasmodium since infection is much more common than disease. The delay for onset of clinical symptoms is longer in temperate zones than in endemic areas. The type of parasite could account for this difference since African congenital malaria are due to Plasmodium falciparum while most cases described in the United States are due to Plasmodium vivax. We also discuss the possible implications of coinfection by HIV in the mother.

Épidémiologie et résistance aux antibiotiques de Streptococcus pneumoniae en Île de France en 2001

OBJECTIVE

The authors wanted to assess the level of Streptococcus pneumoniae antibiotic resistance in Ile de France.

METHOD

In 2001, 637 clinical strains of S. pneumoniae were prospectively collected from 32 microbiology laboratories.

RESULTS

Fifty one percent of strains were isolated from children under 15 years of age and 49% from adults. In children, 76% of strains came from otitis media, 20% from blood culture, in adults most strains (92%) came from blood culture. The overall prevalence of non-susceptible penicillin pneumococci was 61% higher in children (73%) than in adults (50%). Among the non-susceptible penicillin pneumococci 21.8% were resistant (CMI > 1 mg/l). Strains with decreased susceptibility to amoxicillin and cefotaxime were 38% and 17% respectively. Resistant strains to these two drugs (CMI > 2 mg/l) were rare 2.6% and 0.4% respectively. Among other antimicrobial agents, rate of resistance was 63% to erythromycin, 47% to cotrimoxazole, 40% to tetracycline, and 23% to chloramphenicol. The most frequent serogroups were serogroups 19 and 14, respectively 23% and 18%. Serotypes included in heptavalent vaccine covered 90% of children strains under 2 years of age.

CONCLUSIONS

The prevalence of resistance to penicillin was high in children particularly in otitis media pus (76%).

Utilization of 16S ribosomal DNA sequencing for diagnosis of septicemia due to Neisseria elongata subsp. glycolytica in a neutropenic patient

Septicemia due to Neisseria elongata subsp. glycolytica occurs infrequently. We report a case of septicemia in a patient undergoing antimitotic chemotherapy. Gram-negative coccobacilli were isolated from blood cultures. The identity of the isolate by phenotypic methods was uncertain. In contrast, identity was confirmed by 16S ribosomal DNA sequencing, which appeared to be very useful for correct identification.

Integron-associated antibiotic resistance in Salmonella enterica serovar typhi from Asia

Eighteen of 25 isolates of Salmonella enterica serovar Typhi were multidrug resistant and contained class 1 integrons with a single cassette, dfrVII or aadA1. The dfrVII-containing integron was likely borne on an IncHI1 plasmid. Salmonella serovar Typhi could become resistant to broad-spectrum cephalosporins by integrating cassettes, such as veb-1, a common cassette in Asia.

Septic shock caused by Ochrobactrum anthropi in an otherwise healthy host

Reported is a case of life-threatening septic shock that occurred in an otherwise healthy host after administration of a peripheral venous infusion of a solution contaminated with Ochrobactrum anthropi, an unusual human pathogen. The rapid onset of shock may have been due to a large inoculum caused by nonsterile practices at the time of reconstitution.

[Susceptibility of Clostridium difficile to metronidazole using the E-test: effect of the culture medium]

The treatment of intestinal Clostridium difficile infections rests on administration of either a glycopeptide or metronidazole. Given the current shifts in resistance patterns of anaerobes to antimicrobials, a study of the susceptibility of C. difficile to metronidazole was timely. The objective of this study was to evaluate the influence of the culture medium on the Minimal Inhibitory Concentration (MIC) of metronidazole as determined using the E-test. Thirty-one strains were grown on three different media supplemented with 5% horse blood, namely Columbia agar, Wilkens Chalgren agar, and Brucella agar. Results were compared to those obtained using the reference agar dilution method (ADM). As recommended by the French Society for Microbiology, susceptibility was defined as an MIC < or = 4 mg/L. When used on strains susceptible by the ADM, the E-test yielded lower values than the ADM with all three media. Furthermore, findings suggest that E-test results obtained with strains whose MIC is in the 4 to 8 mg/L range by the ADM should be interpreted with caution and, in some cases, tested using the ADM.

Protease activity ofClostridium difficilestrains

The production of proteolytic enzymes by 10 Clostridium difficile isolates of varying toxigenicity and clinical origin was studied to determine if all isolates secreted proteases. Different protease substrates were studied: gelatin, collagen, phenylazobenzyloxycarbonyl-leucyl-glycyl-L-prolyl-D-arginine (Pz-peptide), casein, azocasein, and azocoll. All isolates degraded gelatin, collagen, and azocoll. The supernatants of all isolates contained an enzyme capable of attacking gelatin incorporated in a polyacrylamide gel (zymograms) and forming two closely spaced lytic bands with an estimated molecular mass of 35→40 kDa. Polyclonal antibodies, produced against the C. difficile gelatinase, revealed in Western blots a 35-kDa protein in the culture supernatants of all C. difficile isolates. In the same manner, Clostridium perfringens collagenase polyclonal antibodies detected a 120-kDa protein in the culture supernatants of all isolates; this suggests that at least two proteases may exist in C. difficile. The protease activities of the 10 strains examined did not seem strikingly different quantitatively but were in general weak and their role in pathogenicity is suspect.Key words: Clostridium difficile, proteolytic enzymes.

Protease activity of Clostridium difficile strains

The production of proteolytic enzymes by 10 Clostridium difficile isolates of varying toxigenicity and clinical origin was studied to determine if all isolates secreted proteases. Different protease substrates were studied: gelatin, collagen, phenylazobenzyloxycarbonyl-leucyl-glycyl-L-prolyl-D-arginine (Pz-peptide), casein, azocasein, and azocoll. All isolates degraded gelatin, collagen, and azocoll. The supernatants of all isolates contained an enzyme capable of attacking gelatin incorporated in a polyacrylamide gel (zymograms) and forming two closely spaced lytic bands with an estimated molecular mass of 35-40 kDa. Polyclonal antibodies, produced against the C. difficile gelatinase, revealed in Western blots a 35-kDa protein in the culture supernatants of all C. difficile isolates. In the same manner, Clostridium perfringens collagenase polyclonal antibodies detected a 120-kDa protein in the culture supernatants of all isolates; this suggests that at least two proteases may exist in C. difficile. The protease activities of the 10 strains examined did not seem strikingly different quantitatively but were in general weak and their role in pathogenicity is suspect.

Acute respiratory distress syndrome due to falciparum malaria in a pregnant woman

We report the case of a pregnant woman (29th week), living in a Paris suburb, about 20 miles from an international airport. She presented with septic shock and severe acute respiratory distress syndrome (ARDS). A few parasitized erythrocytes were discovered in a hemorrhagic bronchoalveolar lavage (BAL), specimen and many were found on examination of the placenta after a caesarean section had been performed. The patient's condition dramatically improved once given quinine therapy. This is an uncommon case on account of: (1) the unusual clinical course with no organ failure but ARDS, (2) the unusual way the diagnosis was made, (3) the very unusual way the patient became contaminated (airport malaria), (4) the pregnant condition of the patient.

Evaluation of a rapid agglutination test for detection of group B streptococci in the gastric aspirates of neonates

A rapid commercial agglutination test (Bactigen Strepto B) for detection of group B streptococci in gastric aspirates of neonates was evaluated. One hundred and sixty-one gastric samples were analyzed with conventional bacteriological techniques and with the commercial test after modification of the extraction technique. The sensitivity of the test relative to the culture technique was 90.4%, the specificity 94.2%, the positive predictive value 70.3% and the negative predictive value 98.5%. The commercial test could be performed in one hour and showed good sensitivity and specificity. If a test result was negative colonization could be excluded, obviating the need for empirical antibiotic therapy, whereas a positive result suggested colonization or neonatal infection with group B streptococci.

Corynebacterium diphtheriae osteomyelitis in an immunocompetent child: a case report

Septic osteomyelitis of the hip in a previously healthy child is described. A weakly toxigenic Corynebacterium diphtheriae strain was isolated from the bone aspirate. The results of the treatment were rapidly satisfactory, after surgical drainage and antibiotic therapy with pristinamycin.

CONCLUSION

This case report shows that C. diphtheriae has not disappeared in the developed world and can be responsible of systemic infections.

Enterobacter cloacae cross-colonization in neonates demonstrated by ribotyping

The intestinal colonization by Enterobacter cloacae strains with a derepressed cephalosporinase was studied in a paediatric ward between February 1990 and January 1991. Environmental sampling was performed simultaneously. Fifty-two isolates were recovered from 200 neonates (stool, blood) and 14 strains were isolated from the neonatal environment. An epidemiological study based on the typing of 36 Enterobacter cloacae isolates was carried out using antibiotyping, biotyping and ribotyping methods. The isolates selected were from 21 neonates (24 isolates), the neonatal ward environment (8 isolates) and from other wards (4 isolates). Thirty-two isolates had the same antibiotic resistance pattern, corresponding to a derepressed cephalosporinase and resistance to the following aminoglycosides: kanamycin, gentamicin, tobramycin and netilmicin. No predominant biotyping pattern could be established. Ribotyping done with two endonucleases (EcoRI and BamHI) showed 28 Enterobacter cloacae isolates to have a single pattern. Ribotyping was the most discriminating method used in this study, permitting identification of cross-contamination with Enterobacter cloacae in the paediatric ward.

Antiviral action of trehalose dimycolate against EMC virus: role of macrophages and interferon alpha/beta

Preventive treatment of mice with trehalose 6,6' dimycolate (TDM), an immunomodulator of bacterial origin, enhances their resistance to encephalomyocarditis (EMC) virus infection. The protective effect of TDM is totally abolished by the injection of silica particles in mice, demonstrating the role of macrophages in the antiviral action of TDM. In vitro, peritoneal macrophages from mice treated with TDM (TDM-PM) exhibit an intrinsic antiviral activity against EMC virus, while resident peritoneal macrophages (RES-PM) are permissive to this virus. Greater amounts of interferon are detected in supernatants of cultures of TDM-PM than of RES-PM. Neutralization of interferon (IFN) by addition in vitro of anti-IFN alpha/beta serum markedly reduces the antiviral activity of TDM-PM. These results indicate that interferon alpha/beta is involved in the intrinsic anti-EMC virus activity of peritoneal macrophages from mice treated with TDM.