https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-0691.2003.00560.x

Viruses causing gastroenteritis.

The aims of this study were to investigate the prevalence of campylobacteria including Campylobacter jejuni subsp. jejuni (C. jejuni) and Campylobacter coli in human clinical samples and in samples from healthy individuals and to reevaluate the efficacies of conventional selective methods for isolation of Campylobacter spp. Two charcoal-based selective media, modified charcoal cefoperazone deoxycholate agar (mCCDA) and cefoperazone-amphotericin-teicoplanin (CAT) agar, were compared with Skirrow's blood-based medium and with a filter method (filter) applied to a yeast-enriched blood agar. A total of 1,376 specimens were tested on all four media, and the percentages of thermophilic Campylobacter-positive specimens isolated on Skirrow's medium, filters, CAT agar, and mCCDA were 82, 83, 85, and 95%, respectively. When additional samples were processed with the three selective media, mCCDA recovered significantly more thermophilic Campylobacter spp. than Skirrow's medium (P = 0.0034). No significant difference between Skirrow's medium and CAT agar was observed in this study. Another six taxa were identified, namely, Campylobacter concisus, Campylobacter curvus-like bacteria, Arcobacter butzleri, Arcobacter cryaerophilus, Helicobacter cinaedi, and Sutterella wadsworthensis. Most of these strains were isolated after 5 to 6 days of incubation by use of the filter technique. This paper provides evidence for the existence of S. wadsworthensis in human feces from clinical cases of gastrointestinal disorders and in feces from a healthy individual. Furthermore, C. concisus was isolated from a large number of diarrheal cases, particularly those at the extremes of age, but was additionally isolated from the feces of healthy people. Further investigations to establish the role of C. concisus and S. wadsworthensis in enteric disease is needed. We conclude that a range of campylobacteria may cause infections in Denmark.

Prevalence of Campylobacter, Arcobacter, Helicobacter, and Sutterella spp. in Human Fecal Samples as Estimated by a Reevaluation of Isolation Methods for Campylobacters

During an 8-year study period, Arcobacter butzleri was the fourth most common Campylobacter-like organism isolated from 67,599 stool specimens. Our observations suggest that A. butzleri displays microbiologic and clinical features similar to those of Campylobacter jejuni; however, A. butzleri is more frequently associated with a persistent, watery diarrhea.

/pdf/arcobacter-species-in-humans-3vxjsfzt88.pdf

Arcobacter species in humans.

Results: In total, 85 Campylobacter upsaliensis ,2 0Campylobacter concisus ,1 1Campylobacter fetus, 61 Arcobacter butzleri and 10 Arcobacter cryaerophilus isolates were tested. Most C. upsaliensis strains were susceptible to ampicillin (100%), gentamicin (100%), ciprofloxacin (94.1%) and tetracycline (100%), whereas 11.8 and 12.9% were resistant to nalidixic acid and erythromycin, respectively. For A. butzleri, 78.7% of isolates were susceptible to ampicillin and erythromycin. Most A. butzleri isolates were susceptible to ciprofloxacin (96.7%), nalidixic acid (82.0%), gentamicin (100%) and tetracycline (100%). All C. concisus strains were fully susceptible to ampicillin and tetracycline, but 5% of them were resistant to gentamicin, ciprofloxacin and erythromycin. Nearly all C. fetus and A. cryaerophilus strains were susceptible to erythromycin but the results should be interpreted with caution since only a small number of strains were tested. Conclusions: Fluoroquinolones should be considered in the treatment of severe C. upsaliensis and A. butzleri infection. When clinically indicated, erythromycin remains the first choice for the treatment of intestinal campylobacteriosis caused by C. concisus and C. fetus.

/pdf/antimicrobial-susceptibility-of-clinical-isolates-of-non-3ojc8ke0do.pdf

Antimicrobial susceptibility of clinical isolates of non-jejuni/coli campylobacters and arcobacters from Belgium

This study assessed the epidemiologic characteristics of acute viral gastroenteritis in hospitalized children. A stool sample obtained from each child was analyzed for the presence of astrovirus, calicivirus, rotavirus, adenovirus, enterovirus, and digestive bacteria. Of the 438 stool samples obtained, 138 tested positive for > or =1 pathogen during the winters of 1997-1998 and 1998-1999 (P or =1 virus in 5.4%. Median age was higher for patients with rotavirus gastroenteritis than it was for those with astrovirus or calicivirus gastroenteritis (P=.014). Mean duration of hospitalization was statistically significantly lower for children with rotavirus gastroenteritis (P=.022), despite the more-frequent dehydration observed among children with rotavirus versus those with astrovirus or calicivirus gastroenteritis (P=.007). In contrast, enteral rehydration was more rapidly achieved in patients with gastroenteritis due to rotavirus.

/pdf/epidemiology-of-acute-viral-gastroenteritis-in-children-clwt8vzizp.pdf

Epidemiology of Acute Viral Gastroenteritis in Children Hospitalized in Rouen, France

Some techniques available at our laboratory were tested for their ability to aid in the morphological diagnosis of hydatid elements (Echinococcus granulosus [“Taenia echinococcus”]) isolated from cysts in humans and sheep. Unstained, methanol-fixed hooklets were fluorescent, most starkly so under violet light (excitation filter wavelength, 405 nm; long-pass filter wavelength, 495 nm). Auramine-rhodamine and Gram procedures failed to stain hooklets. Ziehl-Neelsen stain yielded indifferent results when organisms were viewed under transmitted light but resulted in a surprisingly intense red fluorescence when organisms were viewed under green light (excitation, 546 nm; long pass, 590 nm). Wheatley trichrome stain gave better and more uniform results than fuchsin. Ryan trichrome blue stain was the best under transmitted light; hooklets stained uniformly and intensely and were easily distinguishable from the background. Very satisfactory results were also obtained with a much simpler procedure (modified Baxby technique: no fixation, steaming hot 1% safranin for 2 min, and malachite green for 30 s). Therefore, Ryan and modified Baxby stains are recommended for the examination of E. granulosus under transmitted light. For fluorescence microscopy, Ziehl-Neelsen stain under green excitation light, or violet light with no staining, is also very useful. Epifluorescence microscopy is especially convenient for examining samples concentrated by filtration, as it renders the filter pores inconspicuous.

Visualization of Hydatid Elements: Comparison of Several Techniques

A study was conducted to assess the value of a combination of two culture methods for isolation ofCampylobacter spp. from Spanish children. Seven hundred twenty-nine diarrhoea] stool specimens from 599 patients were examined forCampylobacter spp. by culturing them on charcoal cefoperazone deoxycholate agar and on blood agar with a membrane filter. One hundred sixteenCampylobacter strains were isolated from a total of 108 specimens; 75 (64.6%) wereCampylobacter jejuni, 32 (27.5%) wereCampylobacter coli, 8 (6.8%) were non-typeable, and one (0.9%) wasCampylobacter upsaliensis. Campylobacters were isolated from 99 positive samples using charcoal cefoperazone deoxycholate agar alone. The filtration technique alone yielded only 86 positive samples. Seven specimens yielded differentCampylobacter spp. with different media. The only catalase-negative strain was recovered using the filter method. The combination of the selective medium with the filter method increased the isolation rate ofCampylobacter strains by 14.1%. Isolation rates of campylobacters using the filter method were similar to those reported in European studies, in which a similar frequency ofCampylobacter upsaliensis was observed. The addition of a filter method for routine laboratory isolation of campylobacters should be considered in selected age groups (in children <10 years of age) or in areas where catalase-negative or weakly-positiveCampylobacter strains may be of epidemiological significance.

Use of a Selective Medium and a Membrane Filter Method for Isolation of Campylobacter Species from Spanish Paediatric Patients

The incidence of astrovirus infection in children less than 10 years of age with gastroenteritis in the city of Zaragoza, Spain, was analysed during a 12-month period. A total of 718 stool samples obtained from 534 children were examined. In 401 samples no routinely searched for pathogenic organism was detected; these specimens were then tested for the presence of astrovirus antigens. Astrovirus was detected in the samples of 15 (5.5%) patients, a detection rate similar to that recognised for Yersinia enterocolitica and Cryptosporidium spp. All children with confirmed astrovirus infection had diarrhoea (median duration, 9 days), 11 experienced loss of appetite, 5 vomiting, and 4 fever. The incidence of astrovirus infection reported here indicates that Spanish children suffering from gastroenteritis should be routinely screened for the presence of astrovirus.

Astrovirus infection among children with gastroenteritis in the city of Zaragoza, Spain.

Nalidixic acid resistance is a marker of quinolone sensibility in Salmonella spp. In our laboratory we observed an increase of nalidixic acid resistant strains from 0.44% in 1990 to 13.7% in 1996. The purpose of this work was to study the evolution of nalidixic acid resistance in Salmonella spp., as well as the association with certain serotypes and the cross-resistance to others agents. A total of 1,782 isolates of Salmonella enterica were studied from fecal and blood sources over a 7-year period; 45 strains (2.52%) were resistant to nalidixic acid (MIC > 16 microgram/ml). Two isolates required 2 microgram/ml of ciprofloxacin for inhibition, while the remaining 43 strains required 1 microgram/ml. The most frequent serotypes in nalidixic acid resistant strains were the following: enteritidis (33.3%), hadar (31.11%) and virchow (15.5%). In 1996, enteritidis was the predominant serotype (13/31), and hadar serotype was found to have the greatest nalidixic acid resistance at 80% of strains. No differences of sensibility to other agents were detected between the nalidixic acid resistant group and nalidixic acid sensitive strains. This type of resistance appears regularly in uncommon serotypes such as hadar. The increasing incidence of resistant isolates in enteritidis in 1996 is of even greater concern.

Quinolone resistance in Salmonella enterica

SARS-CoV-2 antigen-based tests are well-calibrated to infectiousness and have a critical role to play in the COVID-19 public health response. We report the development and performance of a unique lateral flow immunoassay (LFA).Combinations of several monoclonal antibodies targeting multiple antigenic sites on the SARS-CoV-2 nucleocapsid protein (NP) were isolated, evaluated, and chosen for the development of a LFA termed CoV-SCAN (BioMedomics, Inc.). Clinical point-of-care studies in symptomatic and asymptomatic individuals were conducted to evaluate positive predictive agreement (PPA) and negative predictive agreement (NPA) with RT-PCR as comparator.In laboratory testing, CoV-SCAN detected 14 recombinant N-proteins of SARS-CoV-2 variants with sensitivity in the range of 0.2-3.2 ng/mL, and 10 authentic SARS-CoV-2 variants with sensitivity in the range of 1.6-12.5 TCID50/swab. No cross reactivity was observed with other human coronaviruses or other respiratory pathogens. In clinical point-of-care testing on 148 individuals over age 2 with symptoms of ≤5 days, PPA was 87.2% (CI 95: 78.3-94.8%) and NPA was 100% (CI 95: 94.2-100%). In another 884 asymptomatic individuals, PPA was 85.7% (CI 95: 42.1-99.6%) and 99.7% (99.0-99.9%). Overall, CoV-SCAN detected over 97.2% of specimens with CT values <30 and 93.8% of nasal swab specimens with the Omicron variant, even within the first 2 days after symptom onset.The unique construction of CoV-SCAN using two pairs of monoclonal antibodies has resulted in a test with high performance that remains durable across multiple variants in both laboratory and clinical evaluations. CoV-SCAN should identify almost all individuals harboring infectious SARS-CoV-2.Unique construction of a point-of-care rapid antigen test using two pairs of monoclonal antibodies has led to good performance that remained durable across multiple variants in laboratory and clinical evaluations. Test should identify almost all individuals harboring infectious SARS-CoV-2. 

https://doi.org/10.1016/j.jcvp.2022.100080

L. López

Papers

Visualization of Hydatid Elements: Comparison of Several Techniques

Use of a Selective Medium and a Membrane Filter Method for Isolation of Campylobacter Species from Spanish Paediatric Patients

Astrovirus infection among children with gastroenteritis in the city of Zaragoza, Spain.

Quinolone resistance in Salmonella enterica

Development and performance of a point-of-care rapid antigen test for detection of SARS-COV-2 variants