Susceptibility of Legionella pneumophila to antimicrobial agents and the presence of the efflux pump LpeAB.

OBJECTIVES: Legionella pneumophila strains resistant to antimicrobial agents are rare. We tested 10 antimicrobial agents against clinical and environmental strains and performed WGS to screen for the presence of resistance mechanisms. METHODS: A total of 122 clinical and environmental strains of L. pneumophila collected between 2000 and 2017 and characterized by serogroup and ST were included. Antimicrobial susceptibility was tested by gradient diffusion tests on buffered charcoal yeast extract agar medium supplemented with α-ketoglutarate (BCYE-α) and a subgroup of strains were whole-genome sequenced using Illumina technology and analysed. RESULTS: All strains showed a WT MIC distribution for ciprofloxacin, levofloxacin, moxifloxacin, rifampicin, cefotaxime, tetracycline and trimethoprim/sulfamethoxazole. All strains of L. pneumophila serogroup 1, ST1 (18/122; 14.7%) showed reduced susceptibility to azithromycin (MIC 0.5-1 mg/L) and harboured the efflux pump component lpeAB. Two strains of L. pneumophila serogroup 5 (ST1328) and one strain of serogroup 4 (ST1973) also showed reduced susceptibility to azithromycin (MIC 0.5 mg/L). They harboured lpeAB gene variants with 91.37% and 92.52% nucleotide identity, respectively, compared with the lpeAB genes of serogroup 1, ST1 strains. CONCLUSIONS: Our collection of L. pneumophila strains was susceptible to most antimicrobial agents except azithromycin. Gradient diffusion tests on BCYE-α test medium detected strains with reduced susceptibility to azithromycin. All L. pneumophila serogroup 1, ST1 strains showed reduced susceptibility to macrolides and contained the efflux pump component lpeAB. Reduced susceptibility to azithromycin in non-serogroup 1 strains may be due to the presence of an lpeAB efflux pump variant.

Long-term faecal carriage in infants and intra-household transmission of CTX-M-15-producing Klebsiella pneumoniae following a nosocomial outbreak.

OBJECTIVES: To investigate the duration of faecal carriage of CTX-M-15-producing Klebsiella pneumoniae in infants colonized during a nosocomial neonatal intensive care unit (NICU) outbreak after discharge from hospital, possible risk factors for long-term colonization and transmission to household contacts (HCs). METHODS: Fifty-one infants colonized with two unrelated clones of CTX-M-15 K. pneumoniae [sequence type (ST) 17 and ST485] during an NICU outbreak and 60 HCs provided faecal and rectal samples, respectively, every 1-3 months after hospital discharge. Extended-spectrum ß-lactamase (ESBL)-producing strains of K. pneumoniae were identified on Chrom ID ESBL agar and examined by antimicrobial susceptibility testing. blaCTX-M-15 was detected by PCR and DNA sequencing. Clonal relationship was examined by PFGE. RESULTS: The median carriage time in infants after discharge was 12.5 months (IQR 9.5-17.5). Stable antimicrobial susceptibility patterns in PFGE-related strains confirmed the intestinal persistence of both outbreak strains. Risk factors for prolonged faecal carriage in infants were delivery by caesarean section [hazard ratio (HR) 2.4, 95% CI 1.1-5.5, P = 0.029] and treatment with antibiotics during hospitalization (HR 4.5, 95% CI 1.6-12.6, P = 0.004). Transmission of CTX-M-15 K. pneumoniae was observed in 9/28 (32%) households. Median carriage length in parents was 2.5 months (IQR 1.0-5.0) (P < 0.001 compared with infants). CONCLUSIONS: Infants may be long-term faecal carriers of ESBL-producing K. pneumoniae after colonization during hospitalization in the neonatal period. Delivery by caesarean section and antibiotic treatment during hospitalization are possible risk factors for prolonged carriage. Faecal ESBL carriage in infants represents a reservoir for intra-household spread of ESBL-producing K. pneumoniae.

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial.

BACKGROUND: As most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system. METHOD: We conducted a population based randomized controlled trial among all persons aged 18-25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group. RESULTS: In the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention. CONCLUSION: In Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.

Risk factors for acquisition of CTX-M-15 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae during an outbreak in a neonatal intensive care unit in Norway.

BACKGROUND: A CTX-M-15 extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae was responsible for an outbreak in the neonatal intensive care unit (NICU) at Stavanger University Hospital, Norway over a 5-month period (November 2008-April 2009). The risk factors for acquiring ESBL-producing K. pneumoniae during the outbreak were examined in this study. METHODS: Faecal or rectal cultures were obtained from infants hospitalized in the NICU during the outbreak period and examined for ESBL-producing K. pneumoniae. Data were retrospectively retrieved from the medical records, including sex, gestational age, birth weight, indwelling central vascular catheter, continuous positive airway pressure (CPAP), mechanical ventilation, parenteral nutrition, antibiotic treatment, mode of delivery (vaginal vs caesarean), length of hospital stay, and mortality. RESULTS: A total of 216 infants were hospitalized in the NICU during the outbreak period, of whom 212 were screened; 51 (24%) scored positive for faecal colonization with ESBL-producing K. pneumoniae. One infant acquired a clinical infection. Forty-four colonized infants and 55 non-colonized infants were included in the risk analysis. Colonized infants had a lower birth weight, lower gestational age, and a longer hospital stay compared to non-colonized infants. By logistic regression, prematurity (gestational age <37 weeks) and treatment with antibiotics were independent risk factors for acquiring ESBL-producing K. pneumoniae in the final model. CONCLUSION: Prematurity and treatment with antibiotics were independent risk factors for colonization during this NICU outbreak with ESBL-producing K. pneumoniae.

First outbreak of extended-spectrum ß-lactamase-producing Klebsiella pneumoniae in a Norwegian neonatal intensive care unit; associated with contaminated breast milk and resolved by strict cohorting.

Neonatal intensive care units (NICUs) are vulnerable to nosocomial outbreaks caused by multiresistant Enterobacteriaceae, but no reports of NICU outbreaks of extended-spectrum ß-lactamase (ESBL) producing Klebsiella pneumoniae have previously been published from countries with a low level of antimicrobial resistance such as the Scandinavian countries. We describe a clonal outbreak of CTX-M-15 -producing Klebsiella pneumoniae affecting 58 infants in the neonatal intensive care unit at Stavanger University Hospital, Norway, during a period of 4 months, 2008-2009. The clone spread widely and rapidly in the NICU, and extensive interventions were required to terminate the outbreak. In contrast to previous outbreaks, only one infant acquired a systemic infection caused by the outbreak strain, probably due to a favourable epidemic strain lacking the most common virulence factors. A probable index case was identified, due to multiple positive breast milk samples collected from the infant's mother before and after the infant's transfer from another hospital. Breast milk samples from 3/18 (17%) mothers of colonized infants were positive for ESBL-producing K. pneumoniae. Vertical transmission of ESBL-producing bacteria has been shown previously,’but the possibility of transmission of ESBL-producing K. pneumoniae through expressed breast milk is reported here for the first time. The increasing occurrence of ESBL-producing’Enterobacteriaceae should therefore encourage changes in diagnostic routines for bacterial screening of breast milk.

Lyme meningitis, the major cause of childhood meningitis in an endemic area: a population based study.

OBJECTIVE: To evaluate the epidemiology of infectious meningitis in children in a Lyme borreliosis (LB) endemic area, and to study how clinical and laboratory characteristics may distinguish between different types of childhood meningitis. DESIGN: Retrospective, population based study. SETTING: A paediatric department serving all children (62 000) in a costal LB endemic region of southwestern Norway. PATIENTS: All children with cerebrospinal fluid pleocytosis aged 3 months to 14 years. MAIN OUTCOME MEASURES: Epidemiological, clinical and laboratory characteristics of different types of childhood meningitis. RESULTS: Infectious meningitis was diagnosed in 211 children (annual incidence 38/100 000). Lyme meningitis (LM) was identified in 142 children (67%), non-Lyme aseptic meningitis in 46 children (22%) and bacterial meningitis in 23 children (11%). Age, month of admission and clinical and laboratory characteristics differed between the groups. An aetiological agent was found in 89% of children. The positive predictive value for having LM if the child had facial nerve palsy or head and/or neck stiffness (meningism) as the only symptom was 97% for both variables. Symptoms of cerebral involvement or signs of systemic inflammation were rare in children with LM compared to children non-Lyme aseptic meningitis. CONCLUSION: LM was diagnosed in two-thirds of children with infectious meningitis in this LB endemic area. Distinct clinical characteristics distinguished the majority of children with LM from children with non-Lyme aseptic meningitis and bacterial meningitis.

Quantification of Clostridium difficile in antibiotic-associated-diarrhea patients.

Comparing culture- and non-culture-based methods for quantifying Clostridium difficile in antibiotic-associated-diarrhea patients, we found that the real-time PCR method correlated well with quantitative culture and was more sensitive. A positive association between the population levels of C. difficile and the presence of its toxins was found.

Intestinal lactoflora in Estonian and Norwegian patients with antibiotic associated diarrhea.

The disruption of intestinal microbiota is an important risk factor for the development of Clostridium difficile caused antibiotic associated diarrhea (AAD). The role of intestinal lactoflora in protection against C. difficile is unclear. Fecal samples (n = 74) from AAD patients were investigated for C. difficile and lactobacilli by culture and real-time PCR. Lactobacilli were identified by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and sequencing of 16S rRNA. In C. difficile negative cases we found somewhat higher counts of intestinal Lactobacilli (5.02 vs. 2.15 CFU log(10)/g; p = 0.053) by culture and more frequently Lactobacillus plantarum (33.3% vs. 9.4%; p = 0.03) as compared with positive ones. Results of total counts of lactobacilli comparing Estonian and Norwegian samples were conflicting by culture and PCR. We found higher colonization of Norwegian AAD patients with L. plantarum (21% vs. 5%, p = 0.053) and Estonians with Lactobacillus gasseri (19% vs. 2%, p = 0.023). Particular lactobacilli (e.g. L. plantarum) may have a role in protection against C. difficile, whereas the meaning of total counts of lactobacilli remains questionable. In different persons and nations, different lactobacilli species may have a protective role against C. difficile.

Laboratory data in children with Lyme neuroborreliosis, relation to clinical presentation and duration of symptoms.

The occurrence of IgM and IgG antibodies against Borrelia burgdoferi in serum and cerebrospinal fluid (CSF) and intrathecal synthesis of antibodies (antibody index) were studied in relation to clinical presentation and the duration of symptoms before diagnosis in 146 children diagnosed with neuroborreliosis. Lymphocytic meningitis was demonstrated in 141 of these children. Levels of white blood cells (WBC) and protein in CSF correlated significantly to numbers of d with symptoms. Children were divided into 3 clinical groups: A (n = 37): only cranial neuropathy; B (n = 68): both cranial neuropathy and other neurological symptoms; C (n = 41): neurological symptoms without cranial neuropathy. Levels of WBC and protein in CSF as well as the proportion of children with antibodies in serum and CSF were generally lowest in group A, intermediate in group B and highest in group C. The proportion of children with antibodies in serum and CSF and a positive antibody index was also related to duration of symptoms; the antibody index was present in 51% of children with symptoms < or = 7 d, and in 80% of children with symptoms > 7 d (p<0.01). The clinical presentation and duration of symptoms must be considered when interpreting laboratory data in children with suspected neuroborreliosis.

Acute facial nerve palsy in children: how often is it lyme borreliosis?

Acute facial nerve palsy in children may be caused by infection by Borrelia burgdorferi, but the incidence of facial nerve palsy and the proportion of facial nerve palsy caused by Lyme borreliosis may vary considerably between areas. Furthermore, it is not well known how often facial nerve palsy caused by Lyme borreliosis is associated with meningitis. In this population-based study, children admitted for acute facial nerve palsy to Stavanger University Hospital during 9 y from 1996 to 2004 were investigated by a standard protocol including a lumbar puncture. A total of 115 children with facial nerve palsy were included, giving an annual incidence of 21 per 100,000 children. 75 (65%) of these were diagnosed as Lyme borreliosis, with all cases occurring from May to November. Lymphocytic meningitis was present in all but 1 of the children with facial nerve palsy caused by Lyme borreliosis where a lumbar puncture was performed (n = 73). In this endemic area for Borrelia burgdorferi, acute facial nerve palsy in children was common. The majority of cases were caused by Lyme borreliosis, and nearly all of these were associated with lymphocytic meningitis.

Nosocomial outbreak of CTX-M-15-producing E. coli in Norway.

Seven E. coli isolates expressing resistance to 3rd generation cephalosporins were recovered from blood (n=2), kidney and lung tissue (n=1), and urinary tract (n=4) samples from seven patients hospitalised or recently discharged from the Divisions of Geriatrics and Pulmonary Medicine, Central Hospital of Rogaland, between July and September 2004. All isolates expressed a typical ESBL-cefotaximase profile (cefotaxime MIC>ceftazidime MIC) with clavulanic acid synergy. A bla(CTX-M-15) genotype was confirmed in six strains that were coresistant to gentamicin, nitrofurantoin, trimethoprim-sulfamethoxazole and ciprofloxacin. A bla(CTX-M-3) genotype was detected in the last strain. XbaI-PFGE patterns of the six bla(CTX-M-15) isolates revealed a clonal relationship. Bla(CTX-M-15) strains were also positive for the ISEcp1-like insertion sequences that have been shown to be involved in the mobilization of bla(CTX-M.) Further analyses revealed two bla(CTX-M-15)-positive E. coli urinary isolates clonally related to the outbreak strain from two different patients at the same divisions in January and February 2004. These patients were later re-hospitalised and one had E. coli with an ESBL-cefotaximase profile in sputum and nasopharyngeal specimen during the outbreak period. Clinical evaluation suggests that the CTX-M-producing E. coli strains contributed to death in three patients due to delayed efficient antimicrobial therapy. The outbreak emphasises the epidemic potential of multiple-antibiotic-resistant CTX-M-15-producing E. coli also in a country with low antibiotic usage and low prevalence of antimicrobial resistance.

Factors associated with increased and decreased risk of Campylobacter infection: a prospective case-control study in Norway.

In 1999-2000, a prospective case-control study of sporadic, domestically acquired campylobacteriosis was conducted in three counties in Norway to identify preventable risk factors and potentially protective factors. A total of 212 cases and 422 population controls matched by age, sex, and geographic area were enrolled. In conditional logistic regression analysis, the following factors were found to be independently associated with an increased risk of Campylobacter infection: drinking undisinfected water, eating at barbecues, eating poultry bought raw, having occupational exposure to animals, and eating undercooked pork. The following factors were independently related to a decreased risk: eating mutton, eating raw fruits or berries, and swimming. Results indicated that infection is more likely to occur as a result of cross-contamination from raw poultry products than because of poultry consumption per se. Drinking undisinfected water, reported by 53% of cases, was a leading risk factor in this study. Drinking water may constitute the common reservoir linking infection in humans and animals, including poultry and wild birds. Insight into the ecology of Campylobacter in freshwater ecosystems may be required to understand the epidemiology of campylobacteriosis. The possibility that certain foods confer protection against campylobacteriosis deserves exploration.