Yersinia enterocolitica: its isolation by cold enrichment from patients and healthy subjects.

Routine culture and cold enrichment were compared in a prospective study on the isolation of Yersinia enterocolitica from patients with intestinal disease. Healthy controls were examined with the cold enrichment method only. Y enterocolitica was isolated from 5.9% of 1635 patient stools, 3.4% of 206 appendices, and 4.0% of 555 control stools. Serotypes 0:3 and 0:9 were eight times more prevalent in patients than in controls. Other serotypes were twice as prevalent in controls than in patients. Cold enrichment did not significantly increase the recovery of serotypes 0:3 and 0:9 in acute enteritis, but it was responsible for all isolates of the other serotypes. Evidence is presented that the other serotypes are not pathogenic. In patient stools, Y enterocolitica was demonstrated less frequently than Salmonella (9.1%), and more often than Campylobacter jejuni (1.8%) and Shigella (0.1%).

Surveillance of antibiotic resistance in non invasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winters 2003 and 2004.

A total of 391 and 424 non-invasive isolates of Streptococcus pneumoniae collected by 15 laboratories during the 2003 and 2004 survey were tested for their susceptibility by a microdilution technique following NCCLS recommendations. Insusceptibility rates (IR) in the two surveys (2003/2004) were as follows: penicillin 15.0/14.7% [8.4/6.4% Resistance (R)], ampicillin 17.4/14.6% (R 9.0/7.1%), amoxicillin +/- clavulanic acid 2.6/1.2 % (R 0/0%), cefaclor 14.3/14.1% (R 11.5/13.4%), cefuroxime 13.6/12.7% (R 10.5/11.8%), cefuroxime-axetil 10.5/11.8% (R 10.0/9.2%) (breakpoints based on 250 mg), cefotaxime 4.9/6.2% (R 1.3/2.4%), ceftazidime NotTested (NT)/6.4 (R NT/2.6%), cefepime NT/6.4 (R NT/2.6%), imipenem 7.7/8.9 % (R 1.8/1.4%), ertapenem 0.8/NT% (R O/NT%), ciprofloxacin 13.8/9.0% (R 4.3/2.4%), levofloxacin 3.3/2.8% (R 1.5/0.2%), moxifloxacin 0.6/0.2% (R 0.3/0%), ofloxacin 13.5/9.0% (R 4.3/2.4%), erythromycin 26.1/24.7% (R 25.3/24.5%), azithromycin 25.4/24.7% (R 24.6/24.5%), telithromycin 0.8/0.2% (R 0.5/0%), clindamycin 21.2/18.4% (R 19.2/17.7%) and tetracycline 32.3/22.1% (R 29.2/19.3%). There were only minor differences in resistance rates according to age, sample site, admission type (i.e. ambulatory, hospitalized or long-term care facility patients), gender and geographic origin. Overall, telithromycin (MIC50, MIC90 in 2003/2004: 0.015 microg/ml, 0.12 microg/ml/ 0.008,0.06 respectively), ertapenem (0.03; 0.25/NT), moxifloxacin (0.06; 0.25/0.06, 0.12), and amoxicillin +/- clavulanic acid (0.03; 0.25/0.015, 0.5) were the most active compounds in both surveys. In 2003, the most common resistance phenotype was isolated insusceptibility to tetracycline (10.5%) followed by combined insusceptibility to erythromycin and tetracycline (9.3%). Erythromycin-tetracycline resistance (10.4%) was the most common in 2004. Isolates showing resistance to an antibiotic were significantly more present in 2003 than in 2004 (50.4% versus 40.8%). In penicillin-insusceptible isolates, MICs of all beta-lactams were increased but cross-resistance between penicillin and other beta-lactams in the penicillin-insusceptible isolates was not complete. In the 2003 survey, most of these isolates remained fully susceptible to ertapenem (94.9%) and amoxicillin +/- clavulanic acid (83.1%). In the 2004 survey, 91.9% of the penicillin insusceptible isolates remained susceptible to amoxicillin +/- clavulanic acid. In both surveys, the most common serotypes in penicillin insusceptible isolates were 14, 23,19 and 9 (20.0%, 20.0%, 16.4% and 10.9% respectively in 2003; 41.6%, 11.7%, 15.0% and 18.3% respectively in 2004).

Nonvalue of cold enrichment of stools for isolation of Yersinia enterocolitica serotypes 3 and 9 from patients.

During an 8-year period 14,092 fecal specimens and 1,428 excised appendixes were examined for the presence of Yersinia enterocolitica, with different combinations of direct plating media and enrichment techniques. The combination of direct plating on SS agar and 2 days of enrichment in a modified Rappaport broth at room temperature resulted in the isolation of 100% of serotype 3 and 9 strains. Such strains were recovered from 3.7% of our fecal specimens. Cold enrichment in phosphate buffer further increased the isolation rate, but the additional isolates all belonged to biotype 1. Evidence is presented that biotype 1 strains, at least in Belgium, are not pathogenic for humans. There was a significant affinity of serotype 9 strains for patients suffering from an "appendicular syndrome."

Streptobacillus moniliformis: case report and review of the literature.

Streptobacillus moniliformis is one of the causes of rat bite fever. The clinical and microbiological diagnosis of this rare infectious disease is often quite problematic. Penicillin, in sufficiently high dosis, is the treatment of choice and leads to a prompt resolution of the infection, whereas lack of treatment leads to a 13% mortality rate. As far as we know, this paper reports the first human isolate in Belgium.

Human gastrointestinal infections by Yersinia enterocolitica.

In an average-sized peripheral hospital in Belgium, Y. enterocolitica has been isolated from 1.1% of stool cultures, using an unmodified routine technique. In a group of unselected patients undergoing appendicectomy, 1.3% of patients had a positive culture, either from the mesenteric lymph nodes or the appendix, or from both sources. In the same group of patients, 1.7% of cultures grew a Salmonella. In more than half of the patients, the diagnosis of mesenteric adenitis was made during the surgical intervention. The clinical picture of Yersinia infection was greatly influenced by the age of the patients. Bacteriological (serotypes, antibiotic sensitivity, associated enteric pathogens), epidemiological (sex distribution, seasonal influence and secondary infection among family contacts) and clinical data confirm previous experience with human yersiniosis in this country.

Causative role of Yersinia and other enteric pathogens in the appendicular syndrome.

In 2,861 consecutive patients undergoing appendicectomy for clinically suspected appendicitis an enteric pathogen was isolated from the appendix in almost 7% using an optimal combination of culture media. The pathogenic Yersinia enterocolitica serotypes 03 and 09 predominated (3.6%), followed by Campylobacter and nontyphoid Salmonella. The same pathogen was isolated from the stool in 72.5% of patients with a culture-positive appendix and in 84.1% of those positive for a pathogenic Yersinia. Conversely, no pathogenic Yersinia were isolated in 326 gynaecologic control patients, in whom a normal appendix was removed. No frank appendicitis but mesenteric adenitis and/or terminal ileitis were found in 62.3% of 138 patients with a culture positive appendix, and in 74.6% of those positive for a pathogenic Yersinia. Histologic findings available in 135 patients showed acute suppurative appendicitis in only six (4.5%) patients, and in only one of 73 (1.4%) positive for a pathogenic Yersinia. In contrast, 46.8% of a group of 345 culture-negative appendices showed acute inflammation. A positive stool culture in a patient with suspected appendicitis, if consistent with sonographic and clinical findings, should be taken as strong evidence against the presence of true appendicitis.

Listeria monocytogenes infection of a prosthetic vascular graft.

A 75-year-old man was admitted for acute ischaemia of his right leg for which he had undergone vascular prosthetic surgery at another hospital, ten and three years before. Cultures of the thrombosed graft and the clots removed on re-operation were positive for Listeria monocytogenes. After parenteral treatment with amoxicillin-clavulanic acid and gentamicin, the patient died from cardiorespiratory failure.

Neonatal sepsis due to nonencapsulated Haemophilus influenzae biotype IV.

A case report of a newborn with sepsis due to nontypable H.Influenzae biotype IV is presented. There were no prematurity nor maternal obstetrical complications involved. The child however suffered from severe respiratory distress. With the aspiration of secretions, the resuscitation with mask oxygen and the empirically started combination of ampicillin and cefotaxime, his condition rapidly improved.

Surveillance of human Yersinia enterocolitica infections in Belgium: 1967-1996.

Between 1967 and 1996, > 18,700 strains of Yersinia species, excluding Yersinia pestis, were recovered in Belgium from a variety of gastrointestinal and extraintestinal sites in patients. Full identification and serotyping were performed by the two Belgian reference laboratories. Yersinia enterocolitica serogroup O:3 predominated (79.4% of strains), followed by serogroup O:9 (11.1%). The remaining 9.5% of isolates belonged to serogroups and related species generally considered nonpathogenic. Acute enterocolitis was the most common clinical form of Y. enterocolitica infection, affecting primarily children younger than 5 years of age. Since 1967, there was a steady increase in isolations every year, with 305 cases in 1975 and up to 1,469 in 1986. From 1987 on, there was a clear decrease in the number of reported cases, although the number of participating laboratories and culture techniques remained constant. This significant decrease in the occurrence of Y. enterocolitica infections may be explained by changes in the slaughtering procedures and eating habits of the population.

Yersinia enterocolitica infections and pork: the missing link.

To determine the risk factors for Yersinia enterocolitica (YE) infection in Belgium, which is the country with the highest incidence of this infection, 40 persons with YE infections due to serotype O:3 (n = 36) or O:9 (n = 4) were compared with matched controls. Most patients had acute gastroenteritis; 1 had a liver abscess. 20% were admitted to hospital; the mean duration of hospital stay was 9 days. YE infection was strongly associated with eating raw pork in the 2 weeks before onset (odds ratio = 12, p = 0.00002), a factor that accounted for 58% of the YE infections studied. 14 (18%) of 79 families surveyed at a well-baby clinic fed their children raw pork from a median age of 18 months. Specific control measures to reduce contamination and consumption of raw pork may reduce the incidence of YE infections.

In vitro susceptibilities of 180 clinical isolates of Haemophilus influenzae to ampicillin, amoxycillin/clavulanate, cefaclor, cefuroxime, cefotaxime, clarithromycin, and azithromycin.

One hundred eighty consecutive, unduplicate isolates of Haemophilus influenzae from clinical specimens collected from November 1994 through February 1995 in nine general hospitals throughout Belgium were examined for beta-lactamase production using a nitrocefin-based test, and for their in vitro susceptibilities to ampicillin, amoxycillin/clavulanate, cefaclor, cefuroxime, cefotaxime, clarithromycin and azithromycin by means of the NCCLS agar dilution test. The isolates were all from respiratory tract specimens. The prevalence of capsular type b was 1.1%, and the overall rate of beta-lactamase production 16.7%. Rates of beta-lactamase production were higher in isolates from children (22.0%) than in those from adults (15.3%), and in isolates from upper respiratory tract specimens (22.0%) than in those from the lower respiratory tract (15.1%). Beta-lactamase-negative ampicillin resistance amounted to 1.1%. Cefotaxime had the highest activity on a weight basis [MIC (minimal inhibitory concentration) for 50% of the isolates tested (MIC50) < or = 0.06 microgram/ml], followed by ampicillin (MIC50 of 0.25 microgram/ml), amoxycillin/clavulanate and cefuroxime (MIC50 of 0.5 microgram/ml), azithromycin (MIC50 of 2 micrograms/ml), cefaclor (MIC50 of 4 micrograms/ml), and clarithromycin (MIC50 of 8 micrograms/ml). Cefotaxime was also the most active drug in terms of susceptibility rates of the isolates (100.0%), followed by amoxycillin/clavulanate and azithromycin (98.9%), cefuroxime (97.2%), cefaclor (89.4%), clarithromycin (82.8%), and ampicillin (82.2%). In conclusion, amoxycillin/clavulanate and cefuroxime retain an excellent activity against H. influenzae, while cefaclor lost some of its activity. The rate of susceptibility to azithromycin was markedly higher than that to clarithromycin; however, its ability to accumulate intracellularly while concentrations in serum and interstitial fluid remain low, should be considered, as it may represent a major drawback to its use in H. influenzae infections.

In vitro susceptibilities of 176 clinical isolates of Streptococcus pneumoniae to 11 beta-lactams, erythromycin, and tetracycline.

One hundred seventy six consecutive, non-duplicate pneumococcal isolates from clinical specimens collected from November 1994 through February 1995 in nine general hospitals throughout Belgium were tested for their in vitro susceptibilities to penicillin, ampicillin, amoxycillin with and without clavulanate, cefaclor, cefuroxime, cefonicid, cefprozil, cefpodoxime, cefotaxime, imipenem, tetracycline, and erythromycin by means of the NCCLS microdilution test. The overall rate of decreased susceptibility to penicillin was 12.5%, including 6.3% of intermediately and 6.3% of fully resistant isolates. Penicillin, ampicillin amoxycillin, amoxycillin/clavulanate, cefuroxime, cefotaxime and imipenem had the highest activity on a weight basis (MIC50 < or = 0.008 microgram/ml), followed by cefpodoxime and erythromycin (MIC50 of 0.015 microgram/ml), cefprozil and tetracycline (MIC50 of 0.12 microgram/ml), and eventually, cefaclor and cefonicid (MIC50 of 0.5 microgram/ml). Aggregate rates of susceptible plus intermediately resistant isolates at NCCLS-recommended breakpoints, i.e. overall percentages of isolates likely to respond to increased antibiotic doses in vivo (except for meningitis), were 100.0% for imipenem and cefotaxime, 98.9% for amoxycillin with and without clavulanate, 93.8% for penicillin, and 90.9% for cefuroxime. Overall rates of susceptibility to erythromycin and tetracycline amounted to 78.4% and 72.7%, respectively. MIC values of all beta-lactams increased with those of penicillin. Ampicillin was equally active as penicillin against isolates with reduced susceptibility to the latter (MIC90 of 2 micrograms/ml); imipenem, cefotaxime, and amoxycillin with and without clavulanate however, were more active (MIC90 3, 1, and 1 doubling dilution, respectively, below that of penicillin), while cefpodoxime, cefuroxime, cefprozil, cefonicid, and cefaclor on the other hand, were less active (MIC90, 1, 1, 2, 5, and 5 doubling dilutions, respectively, above that of penicillin). In conclusion, the present data confirm that pneumococcal resistance to penicillin has increased in Belgium, suggest that resistance to erythromycin may have stabilised, and reveal an unexpectedly high rate of resistance to tetracycline. Imipenem was the most active antibiotic tested overall, and amoxycillin with or without clavulanate the most active oral antibiotic, with activity almost similar to that of cefotaxime.

Surveillance of pneumococcal resistance in Belgium during winter 1996-1997.

This study tested 212 pneumococcal isolates from 9 institutions for their susceptibilities to penicillin, ampicillin, amoxycillin, amoxycillin/clavulanate, cefaclor, cefuroxime, cefotaxime, imipenem, tetracycline, erythromycin, and clarithromycin using NCCLS-standardized microdilution. Penicillin-insusceptibility was 12.3% [5.7% intermediate (0.12-1 microgram/ml) and 6.6% high-level (> or = 2 micrograms/ml)], tetracycline-insusceptibility (> or = 4 micrograms/ml) 31.1%, and erythromycin-insusceptibility (> or = 0.5 microgram/ml) 31.1% as well. Erythromycin-insusceptible isolates showed cross-insusceptibility to clarithromycin. Penicillin-susceptible isolates were susceptible to all beta-lactams. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Ampicillin and penicillin were equally potent against penicillin-insusceptible isolates, imipenem, cefotaxime, and amoxycillin +/- clavulanate were more potent (generally 5, 1, and 1 doubling dilution, respectively), and cefuroxime and cefaclor less potent (generally 1 and 6 doubling dilutions, respectively). Most penicillin-insusceptible isolates were high-level resistant to cefaclor (> or = 32 micrograms/ml). Although MICs of all beta-lactams rose with those of penicillin, resistance to penicillin was not absolute in terms of cross-resistance. Most penicillin-intermediate and high-level penicillin-resistant isolates remained fully susceptible and intermediate, respectively, to amoxycillin +/- clavulanate, cefotaxime, and imipenem, but not to cefuroxime. Penicillin-susceptible isolates were 76.9%, 42.3%, and 34.6% co-insusceptible to tetracycline, erythromycin, and tetracycline plus erythromycin, respectively. Most penicillin-, tetracycline-, and erythromycin-insusceptible isolates were of capsular types 23 >> 6 > 19 > 32, 19 > 6 > 28 > 23, and 19 > 6 > 14 > 23, respectively. Compared to winter 1994-1995, insusceptibility to penicillin, tetracycline, and erythromycin rose by some 4%, 4%, and 13%, respectively.

Surveillance of antibiotic resistance in clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2000-2001.

A total of 314 isolates of Streptococcus pneumoniae collected by 10 different laboratories were tested for their susceptibility by using a microdilution technique following NCCLS recommendations. The following antibiotics were included: penicillin, ampicillin, amoxicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, levofloxacin, erythromycin, clarithromycin, azithromycin, miocamycin, clindamycin and tetracycline. The insusceptibility rate (IR) to penicillin was 21.0% [10.8% intermediate (> or = 0.12-1 microgram/mL) and 10.2% high-level (> or = 2 micrograms/mL)], to cefotaxime 7.3% [3.5% intermediate (> or = 1 microgram/mL) and 3.8% high-level (> or = 2 micrograms/mL)], to imipenem 3.8% [3.8% intermediate (> or = 0.25-0.5 microgram/mL) and 0% high-level (> or = 1 microgram/mL)], to ciprofloxacin 11.2% [8.3% intermediate (2 micrograms/mL) and 3.9% high-level (> or = 4 micrograms/mL)], to erythromycin 30.3% [3.5% intermediate (0.5 microgram/mL) and 26.8% high-level (> or = 1 microgram/mL)] and to tetracycline 38.5% [0.9% intermediate (4 micrograms/mL) and 37.6% high-level (> or = 8 micrograms/mL)]. No decreased susceptibility was found for gemifloxacin (> or = 0.5 microgram/mL). This compound was the most active with MIC50, MIC90 and an IR of 0.015 microgram/mL, 0.03 microgram/mL and 0% respectively, followed by amoxicillin/clavulanate, amoxicillin and imipenem (MIC50, MIC90 and IR: 0.015 microgram/mL, 1 microgram/mL, 1.6%/0.015 microgram/mL, 1 microgram/mL, 1.9%/0.008 microgram/mL, 0.12 microgram/mL, 3.8% respectively). Compared to the 1999 surveillance, penicillin and tetracycline-insusceptibility increased with 4.9% and 15.6% respectively, while cefotaxime, erythromycin and ciprofloxacin insusceptibility decreased with 5.4%, 5.8% and 4.4% respectively. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Imipenem, cefotaxime, amoxicillin and amoxicillin/clavulanate were generally 4, 2, 1 and 1 doubling dilutions respectively more potent than penicillin on these isolates while ampicillin, cefuroxime and cefactor were generally 1, 2 and 4 dilutions respectively [table: see text] less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin/clavulanate (92.4%), amoxicillin (90.9%) and imipenem (81.8%). Erythromycin-tetracycline insusceptibility was the most common resistance phenotype (14.3%). Three- and four-fold resistance was found in 12.4% and 1.6% respectively of the isolates. Most penicillin-insusceptible isolates were of capsular types 14 (22.7%), 23 (21.2%), 6 (18.2%), 9 (13.6%) and 19 (12.1%).

In vitro study on the antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae from Belgium collected during winter 1998-1999.

A total of 205 isolates of Streptococcus pneumoniae obtained from 10 different centres were included in this study. The susceptibilities to penicillin, ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, grepafloxacin, levofloxacin, trovafloxacin, erythromycin, clarithromycin, miocamycin, clindamycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 16.1% [6.8% intermediate (0.12-1 microgram/mL) and 9.3% high-level (> or = 2 micrograms/mL)], cefotaxime insusceptibility (> or = 1 microgram/mL) 12.7%, ciprofloxacine insusceptibility (> or = 2 micrograms/mL) 15.6% with 1.5% of high level resistance (> or = 4 micrograms/mL), erythromycin insusceptibility (> or = 0.5 microgram/mL) 36.1% and tetracycline insusceptibility (> or = 4 micrograms/mL) 22.9%. Decreased susceptibility to cefotaxime was found in 78.8% of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (> or = 0.5 microgram/mL) and trovafloxacin (> or = 1 microgram/mL). Compared to the 1996-1997 surveillance, penicillin, cefotaxime and erythromycin insusceptibility rose by 3.8%, 5.2% and 5.0% respectively, while tetracycline insusceptibility decreased with 8.2%. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Amoxicillin +/- clavulanate, cefotaxime and imipenem were generally 1, 1 and 5 doubling dilutions respectively more potent than penicillin on these isolates. Penicillin, ampicillin and cefuroxime were equally active while cefaclor was generally 5 dilutions less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin +/- clavulanate and imipenem. The penicillin-insusceptible isolates were 36.4%, 27.3% and 3.0% co-insusceptible to erythromycin, erythromycin plus tetracycline and tetracycline respectively. A subpopulation of 52 isolates obtained from children aged < or = 3 years was also studied. Compared to the other isolates we found a statistically significant increase in insusceptibility for penicillin, cefaclor, cefuroxime, erythromycin, clarithromycin and tetracycline while a significant decrease was found for ciprofloxacin.