David Lung

Elizabethkingia anophelis bacteremia is associated with clinically significant infections and high mortality

Unlike Elizabethkingia meningoseptica, the clinical importance of E. anophelis is poorly understood. We determined the clinical and molecular epidemiology of bacteremia caused by Elizabethkingia-like species from five regional hospitals in Hong Kong. Among 45 episodes of Elizabethkingia-like bacteremia, 21 were caused by Elizabethkingia, including 17 E. anophelis, three E. meningoseptica and one E. miricola; while 24 were caused by other diverse genera/species, as determined by 16S rRNA gene sequencing. Of the 17 cases of E. anophelis bacteremia, 15 (88%) were clinically significant. The most common diagnosis was pneumonia (n = 5), followed by catheter-related bacteremia (n = 4), neonatal meningitis (n = 3), nosocomial bacteremia (n = 2) and neutropenic fever (n = 1). E. anophelis bacteremia was commonly associated with complications and carried 23.5% mortality. In contrast, of the 24 episodes of bacteremia due to non-Elizabethkingia species, 16 (67%) were clinically insignificant. Compared to non-Elizabethkingia bacteremia, Elizabethkingia bacteremia was associated with more clinically significant infections (P < 0.01) and positive cultures from other sites (P < 0.01), less polymicrobial bacteremia (P < 0.01), and higher complication (P < 0.05) and mortality (P < 0.05) rates. Elizabethkingia bacteremia is predominantly caused by E. anophelis instead of E. meningoseptica. Elizabethkingia bacteremia, especially due to E. anophelis, carries significant morbidity and mortality, and should be considered clinically significant unless proven otherwise.

Unique reassortant of influenza A(H7N9) virus associated with severe disease emerging in Hong Kong

Summary Objective Human infections caused by avian influenza virus A(H7N9) re-emerged in late 2013. We reported the first Hong Kong patient without risk factors for severe A(H7N9) disease. Methods Direct sequencing was performed on the endotracheal aspirate collected from a 36-year-old female with history of poultry contact. Bioinformatic analysis was performed to compare the current strain and previous A(H7N9) isolates. Results The influenza A/Hong Kong/470129/2013 virus strain was detected in a patient with acute respiratory distress syndrome, deranged liver function and coagulation profile, cytopenia, and rhabdomyolysis. The HA, NA and MP genes of A/Hong Kong/470129/2013 cluster with those of other human A(H7N9) strains. The PB1, PB2 and NS genes are most closely related to those of A/Guangdong/1/2013 strain identified in August 2013, but are distinct from those of other human and avian A(H7N9) strains. The other internal genes NP and PA genes are more closely related to those of non-A(H7N9) avian influenza A viruses. A unique PA L336M mutation, associated with increased polymerase activity, was found. The patient required salvage by extracorporeal membrane oxygenation. Conclusions The A/Hong Kong/470129/2013 virus is a novel reassortant derived from A/Guangdong/1/2013 virus. The unique mutation PA L336M may enhance viral replication and therefore disease severity.

Detection of human rhinovirus C in fecal samples of children with gastroenteritis

Abstract Background Despite recent discovery of the novel human rhinovirus species, HRV-C, little is known about the association of HRV-C in diseases other than respiratory tract infections. Objectives To investigate the presence of HRV-C in fecal samples of children with gastroenteritis. Study design 734 fecal samples from hospitalized children with gastroenteritis were subject to picornavirus detection by RT-PCR of the conserved 5′-NCR. Positive samples were subject to VP4 and 3Dpol gene analysis for species determination. The clinical and molecular epidemiology of HRV-C and other picornaviruses was analyzed. Results Picornaviruses were detected in 113 (15.4%) of 734 fecal samples from children with gastroenteritis by RT-PCR of 5′-NCR, with 58 containing potential HRVs and 55 containing other enteroviruses. PCR of the VP4 and 3Dpol regions was positive in 21 and 19 samples respectively (both regions positive in 8 samples). Sequencing analysis showed the presence of HRV-C in four samples, and diverse picornaviruses including HRV-A (n =2), HEV-A (n =2), HEV-B (n =2), HEV-C (n =21) and HPeV (n =2) in other samples, with co-detection of HRV-C and HPeV in one sample. Of the four children with HRV-C detected in fecal samples, three presented with diarrhea in the absence of respiratory symptoms, while one also had acute bronchiolitis. The four HRV-C strains from fecal samples belonged to the existing clade of diverse HRV-C genotypes, indistinguishable from previous respiratory strains. Conclusions HRV-C can be detected in fecal samples of children with gastroenteritis, in the absence of respiratory symptoms. This study also represented the first to detect HPeV in our population.

A cross-sectional survey of snake oral bacterial flora from Hong Kong, SAR, China

Objective To determine the pattern of oral bacterial flora and their sensitivity to antibiotics in freshly captured native snakes in Hong Kong SAR, Peoples Republic of China. Methods Healthy native snakes were captured and kept in a designated centre. Snake species were identified by experienced herpetologists. Mouth swabs were taken by the veterinarian using strict aseptic techniques. The snakes were released back to the wild immediately after the above procedure. Swabs were sent for microbiological studies of bacterial culture and antibiotic sensitivity. Results 47 venomous snakes of the families Colubridae, Elapidae and Viperidae and 53 non-medically important snakes were captured. 406 bacterial isolates of 72 different species were cultured: these included Gram negative and positive bacterial species and also anaerobic bacterial species. With the exception of the white-lipped pit viper (Cryptelytrops albolabris), venomous snakes harboured more pathogenic bacteria and total bacteria species compared to the non-medically important species. Of the venomous snakes, the Chinese cobra (Naja atra) harboured the largest number of bacterial species. In the present study, all Gram negative bacteria associated with wound infection were sensitive to levofloxacin, netilmicin and piperacillin/tazobactam. Many Gram negative bacteria in the study were not sensitive to cefuroxime axetil. Amoxicillin/clavulanic acid was an appropriate choice to cover Enterococcus faecalis and anaerobes. Conclusion In the presence of wound infection from snakebite injury in Hong Kong, first line empirical antibiotics include amoxicillin/clavulanic acid plus levofloxacin. Prophylactic antibiotics may be considered in selected cases of Chinese cobra (N atra) bite, otherwise prophylactic antibiotics are not recommended in snakebite unless tissue necrosis is present.

Complete Sequence of an IncN Plasmid, pIMP-HZ1, Carrying blaIMP-4 in a Klebsiella pneumoniae Strain Associated with Medical Travel to China

In China, IMP-4 is a major plasmid-mediated carbapenemase among multidrug-resistant Enterobacteriaceae, but little is known about the plasmid scaffolds involved in the dissemination of blaIMP-4 (1, 2). In 2010, we identified a Klebsiella pneumoniae CRE1 strain carrying blaIMP-4 from the penile swab of a 49-yearold man who was repatriated from Huizhou, China, where he had been hospitalized for intracranial hemorrhage. The isolate was resistant to all -lactams, including imipenem, ertapenem, and meropenem, and multiple non-lactam antibiotics (chloramphenicol, co-trimoxazole, nitrofurantoin) (3). Combined disc testing (4) showed that carbapenem resistance can be reversed by EDTA but not boronic acid. Multilocus sequence typing (MLST) (5) identified CRE1 as sequence type (ST) 11, which is a major lineage associated with blaKPC dissemination in China (6). Conjugation was carried out in filters with Escherichia coli J53 as the recipient and transconjugants selected with sodium azide (100 g/ml) and meropenem (1 g/ml) (7). The blaIMP-4-carrying plasmid was able to be transferred at a frequency of 1.2 10 4 per donor cell. Plasmid DNA from the transconjugant was extracted, amplified, and sequenced using a GS-FLX system (Roche, Mannheim, Germany) as described previously (7). The assembled plasmid pIMP-HZ1 has 50,775 bp (GenBank accession no. JX457479). pIMP-HN1 has a plasmid scaffold typical for the IncN plasmids in general (8, 9). The backbone regions shared by pIMP-HZ1 and the reference IncN plasmid R46 include the replicon repA, the mucAmucB genes (encoding UV protection), the stbABC operon (for plasmid stability), the ardA-ardB and ardK-ardR genes (with antirestriction function), the ccg genes (ccgEIII-ccgD-ccgC-ccgAIccgAII, providing protection from the type I restriction system), and the two transfer gene clusters (locus tra1 and locus tra2, en-

Influenza-related hospitalisations in children.

Aim:  To describe the disease burden, clinical pattern and outcome of influenza‐related hospitalisations in children.

Rapid defervescence after doxycycline treatment of macrolide-resistant Mycoplasma pneumoniae-associated community-acquired pneumonia in children.

We did a retrospective review of children with Mycoplasma pneumoniae infection hospitalized from March 2010 to March 2013. Mycoplasma-resistant M. pneumoniae constituted 70% of the total M. pneumoniae–associated community-acquired pneumonia. Doxycycline was significantly more effective than macrolide for treatment of Mycoplasma-resistant M. pneumoniae–associated community-acquired pneumonia in terms of achievement of rapid defervescence within 24 hours.

First Report of a Fatal Case Associated with EV-D68 Infection in Hong Kong and Emergence of an Interclade Recombinant in China Revealed by Genome Analysis

A fatal case associated with enterovirus D68 (EV-D68) infection affecting a 10-year-old boy was reported in Hong Kong in 2014. To examine if a new strain has emerged in Hong Kong, we sequenced the partial genome of the EV-D68 strain identified from the fatal case and the complete VP1, and partial 5′UTR and 2C sequences of nine additional EV-D68 strains isolated from patients in Hong Kong. Sequence analysis indicated that a cluster of strains including the previously recognized A2 strains should belong to a separate clade, clade D, which is further divided into subclades D1 and D2. Among the 10 EV-D68 strains, 7 (including the fatal case) belonged to the previously described, newly emerged subclade B3, 2 belonged to subclade B1, and 1 belonged to subclade D1. Three EV-D68 strains, each from subclades B1, B3, and D1, were selected for complete genome sequencing and recombination analysis. While no evidence of recombination was noted among local strains, interclade recombination was identified in subclade D2 strains detected in mainland China in 2008 with VP2 acquired from clade A. This study supports the reclassification of subclade A2 into clade D1, and demonstrates interclade recombination between clades A and D2 in EV-D68 strains from China.

Hemorrhagic shock and encephalopathy syndrome in a child with pandemic H1N1 2009 influenza virus.

We report a case of hemorrhagic shock and encephalopathy in a child with pandemic 2009 H1N1 influenza infection. The patient succumbed within 3 days of admission.