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OBJECTIVES: Acute epiglottitis in adult is a potentially life-threatening condition that may be underdiagnosed. The present study reports the clinical features, management and patient outcomes in an acute hospital in Hong Kong over a seven-year period. METHOD: All adult patients aged 18 years or above admitted to Tuen Mun Hospital between July 1999 and June 2006 with the diagnosis of acute epiglottitis were included in this retrospective study. The diagnosis of acute epiglottitis was established by direct visualisation of inflamed epiglottis during laryngoscopic examination. RESULTS: 106 patients were identified. A total of 21 patients (20%) had co-morbidities, with diabetes mellitus (11%) being the most common. Five patients had a history of nasopharyngeal carcinoma and three patients had a previous history of acute epiglottitis. The majority (94%) of patients presented with sore throat as their major complaint. Blood cultures were collected from 15 patients and all were negative. A combination of cefotaxime and metronidazole was the most common empirical antibiotic regimen prescribed. Seven patients required active airway intervention (six with endotracheal intubation and one failed intubation with emergency tracheostomy performed). No mortality was reported. CONCLUSION: Acute epiglottitis in adults is not a rare entity and vigilance for this condition is needed. In general, the prognosis is good with antimicrobial therapy, close monitoring and selective airway intervention. [ABSTRACT FROM AUTHOR]

During September-October 2021, group B Streptococcus bloodstream infections surged among patients hospitalized in Hong Kong. Of 95 cases, 57 were caused by the hypervirulent strain sequence type 283, which at the time was also found in freshwater fish and wet market environments and thus poses a transmission threat.

Objective: This study aimed to characterize the changing landscape of circulating SARS-CoV-2 lineages in the local community of Hong Kong throughout 2022. We examined how adjustments to quarantine arrangements influenced the transmission pattern of Omicron variants in a city with relatively rigorous social distancing measures at that time., Methods: In 2022, a total of 4684 local SARS-CoV-2 genomes were sequenced using the Oxford Nanopore GridION sequencer. SARS-CoV-2 consensus genomes were generated by MAFFT, and the maximum likelihood phylogeny of these genomes was determined using IQ-TREE. The dynamic changes in lineages were depicted in a time tree created by Nextstrain. Statistical analysis was conducted to assess the correlation between changes in the number of lineages and adjustments to quarantine arrangements., Results: By the end of 2022, a total of 83 SARS-CoV-2 lineages were identified in the community. The increase in the number of new lineages was significantly associated with the relaxation of quarantine arrangements (One-way ANOVA, F(5, 47) = 18.233, p < 0.001)). Over time, Omicron BA.5 sub-lineages replaced BA.2.2 and became the predominant Omicron variants in Hong Kong. The influx of new lineages reshaped the dynamics of Omicron variants in the community without fluctuating the death rate and hospitalization rate (One-way ANOVA, F(5, 47) = 2.037, p = 0.091)., Conclusion: This study revealed that even with an extended mandatory quarantine period for incoming travelers, it may not be feasible to completely prevent the introduction and subsequent community spread of highly contagious Omicron variants. Ongoing molecular surveillance of COVID-19 remains essential to monitor the emergence of new recombinant variants.

Bovine viral diarrhea virus (BVDV) has caused massive economic losses in the cattle business worldwide. Fatty acid synthase (FASN), a key enzyme of the fatty acid synthesis (FAS) pathway, has been shown to support virus replication. To investigate the role of fatty acids (FAs) in BVDV infection, we infected CD8 + T lymphocytes obtained from healthy cattle with BVDV in vitro. During early cytopathic (CP) and noncytopathic (NCP) BVDV infection in CD8+ T cells, there is an increase in de novo lipid biosynthesis, resulting in elevated levels of free fatty acids (FFAs) and triglycerides (TG). BVDV infection promotes de novo lipid biosynthesis in a dose-dependent manner. Treatment with the FASN inhibitor C75 significantly reduces the phosphorylation of PI3K and AKT in BVDV-infected CD8+ T cells, while inhibition of PI3K with LY294002 decreases FASN expression. Both CP and NCP BVDV strains promote de novo fatty acid synthesis by activating the PI3K/AKT pathway. Further investigation shows that pharmacological inhibitors targeting FASN and PI3K concurrently reduce FFAs, TG levels, and ATP production, effectively inhibiting BVDV replication. Conversely, the in vitro supplementation of oleic acid (OA) to replace fatty acids successfully restored BVDV replication, underscoring the impact of abnormal de novo fatty acid metabolism on BVDV replication. Intriguingly, during BVDV infection of CD8 + T cells, the use of FASN inhibitors prompted the production of IFN-α and IFN-β, as well as the expression of interferon-stimulated genes (ISGs). Moreover, FASN inhibitors induce TBK-1 phosphorylation through the activation of RIG-1 and MDA-5, subsequently activating IRF-3 and ultimately enhancing the IFN-1 response. In conclusion, our study demonstrates that BVDV infection activates the PI3K/AKT pathway to boost de novo fatty acid synthesis, and inhibition of FASN suppresses BVDV replication by activating the RIG-1/MDA-5-dependent IFN response., Competing Interests: Declaration of Competing Interest No potential conflict of interest was reported by the author(s)., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The prolonged incubation period of traditional culture methods leads to a delay in diagnosing invasive infections. Nanopore 16S rRNA gene sequencing (Nanopore 16S) offers a potential rapid diagnostic approach for directly identifying bacteria in infected body fluids. To evaluate the clinical utility of Nanopore 16S, we conducted a study involving the collection and sequencing of 128 monomicrobial samples, 65 polymicrobial samples, and 20 culture-negative body fluids. To minimize classification bias, taxonomic classification was performed using 3 analysis pipelines: Epi2me, Emu, and NanoCLUST. The result was compared to the culture references. The limit of detection of Nanopore 16S was also determined using simulated bacteremic blood samples. Among the three classifiers, Emu demonstrated the highest concordance with the culture results. It correctly identified the taxon of 125 (97.7%) of the 128 monomicrobial samples, compared to 109 (85.2%) for Epi2me and 102 (79.7%) for NanoCLUST. For the 230 cultured species in the 65 polymicrobial samples, Emu correctly identified 188 (81.7%) cultured species, compared to 174 (75.7%) for Epi2me and 125 (54.3%) for NanoCLUST. Through ROC analysis on the monomicrobial samples, we determined a threshold of relative abundance at 0.058 for distinguishing potential pathogens from background in Nanopore 16S. Applying this threshold resulted in the identification of 107 (83.6%), 117 (91.4%), and 114 (91.2%) correctly detected samples for Epi2me, Emu, and NanoCLUST, respectively, in the monomicrobial samples. Nanopore 16S coupled with Epi2me could provide preliminary results within 6 h. However, the ROC analysis of polymicrobial samples exhibited a random-like performance, making it difficult to establish a threshold. The overall limit of detection for Nanopore 16S was found to be about 90 CFU/ml., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lao, Wong, Hui, Ng, Chan, Lo, Yau, Leung, Wong, Ho, Yip, Lam, Chow, Luk, Que, Chow and Siu.)

Nonpharmaceutical interventions implemented during the COVID-19 pandemic (2020−2021) have provided a unique opportunity to understand their impact on the wholesale supply of antibiotics and incidences of infections represented by bacteremia due to common bacterial species in Hong Kong. The wholesale antibiotic supply data (surrogate indicator of antibiotic consumption) and notifications of scarlet fever, chickenpox, and tuberculosis collected by the Centre for Health Protection, and the data of blood cultures of patients admitted to public hospitals in Hong Kong collected by the Hospital Authority for the last 10 years, were tabulated and analyzed. A reduction in the wholesale supply of antibiotics was observed. This decrease coincided with a significant reduction in the incidence of community-onset bacteremia due to Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, which are encapsulated bacteria with respiratory transmission potential. This reduction was sustained during two pandemic years (period 2: 2020−2021), compared with eight pre-pandemic years (period 1: 2012−2019). Although the mean number of patient admissions per year (1,704,079 vs. 1,702,484, p = 0.985) and blood culture requests per 1000 patient admissions (149.0 vs. 158.3, p = 0.132) were not significantly different between periods 1 and 2, a significant reduction in community-onset bacteremia due to encapsulated bacteria was observed in terms of the mean number of episodes per year (257 vs. 58, p < 0.001), episodes per 100,000 admissions (15.1 vs. 3.4, p < 0.001), and per 10,000 blood culture requests (10.1 vs. 2.1, p < 0.001), out of 17,037,598 episodes of patient admissions with 2,570,164 blood culture requests. Consistent with the findings of bacteremia, a reduction in case notification of scarlet fever and airborne infections, including tuberculosis and chickenpox, was also observed; however, there was no reduction in the incidence of hospital-onset bacteremia due to Staphylococcus aureus or Escherichia coli. Sustained implementation of non-pharmaceutical interventions against respiratory microbes may reduce the overall consumption of antibiotics, which may have a consequential impact on antimicrobial resistance. Rebound of conventional respiratory microbial infections is likely with the relaxation of these interventions.

Background: Several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages with mutations at the spike protein receptor binding domain (RBD) have reduced susceptibility to antibody neutralization, and have been classified as variants of concern (VOCs) or variants of interest (VOIs). Here we systematically compared the neutralization susceptibility and RBD binding of different VOCs/VOIs, including B.1.617.1 (kappa variant) and P.3 (theta variant), which were first detected in India and the Philippines, respectively., Methods: The neutralization susceptibility of the VOCs/VOIs (B.1.351, B.1.617.1, and P.3) and a non-VOC/VOI without RBD mutations (B.1.36.27) to convalescent sera from coronavirus disease 2019 (COVID-19) patients or BNT162b2 vaccinees was determined using a live virus microneutralization (MN) assay. Serum immunoglobulin G (IgG) binding to wild-type and mutant RBDs were determined using an enzyme immunoassay., Results: The geometric mean neutralization titers (GMT) of B.1.351, P.3, and B.1.617.1 were significantly lower than that of B.1.36.27 for COVID-19 patients infected with non-VOCs/VOIs (3.4- to 5.7-fold lower) or individuals who have received 2 doses of BNT162b2 vaccine (4.4- to 7.3-fold lower). The GMT of B.1.351 or P.3 were lower than that of B.1.617.1. For the 4 patients infected with B.1.351 or B.1.617.1, the MN titer was highest for their respective lineage. RBD with E484K or E484Q mutation, either alone or in combination with other mutations, showed greatest reduction in serum IgG binding., Conclusions: P.3 and B.1.617.1 escape serum neutralization induced by natural infection or vaccine. Infection with 1 variant does not confer cross-protection for heterologous lineages. Immunogenicity testing for second generation COVID-19 vaccines should include multiple variant and "nonvariant" strains., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The increasing prevalence of N501Y variants of SARS-CoV-2 has kindled global concern due to their enhanced transmissibility. Genome sequencing is the gold standard method to identify the emerging variants of concern. But it is time-consuming and expensive, limiting the widespread deployment of genome surveillance in some countries. Health authorities surge the development of alternative assay to expand screening capacity with reduced time and cost. In this study, we developed an in-house TaqMan minor groove binder (MGB) probe-based one-step RT-qPCR assay to detect the presence of N501Y mutation in SARS-CoV-2. A total of 168 SARS-CoV-2 positive respiratory specimens were collected to determine diagnostic accuracy of the RT-qPCR assay. As a reference standard, PANGO lineages and the mutation patterns of all samples were characterised by whole-genome sequencing. The analytical sensitivity and the ability of the assay to detect low frequency of N501Y variants were also evaluated. A total of 31 PANGO lineages were identified from 168 SARS-CoV-2 positive cases, in which 34 samples belonged to N501Y variants, including B.1.1.7 (n = 20), B.1.351 (n = 12) and P.3 (n = 2). The N501Y RT-qPCR correctly identified all 34 samples as N501Y-positive and the other 134 samples as wildtype. The limit-of-detection of the assay consistently achieved 1.5 copies/μL on four different qPCR platforms. N501Y mutation was successfully detected at an allele frequency as low as 10 % in a sample with mixed SARS-CoV-2 lineage. The N501Y RT-qPCR is simple and inexpensive (US$1.6 per sample). It enables robust high-throughput screening for surveillance of SARS-CoV-2 variants of concern harbouring N501Y mutation., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Oxacillin resistance mediated by mecA in Staphylococcus lugdunensis is emerging in some geographic areas. We evaluated cefoxitin disk diffusion (DD) and a new oxacillin agar (supplemented with 2 μg/ml oxacillin and 2% sodium chloride) screen for the detection of mecA -mediated resistance in S. lugdunensis . A total of 300 consecutive, non-duplicated clinical S. lugdunensis isolates from diverse sources in Hong Kong in 2019 were tested. The categorical agreement and errors obtained between cefoxitin DD test, oxacillin agar screen and mecA PCR were analyzed. Isolates with discordant results were further tested by MIC, penicillin binding protein 2a (PBP2a) assays, population analysis and molecular typing. PCR showed that 62 isolates were mecA -positive and 238 isolates were mecA -negative. For cefoxitin DD results interpreted using S. aureus / S. lugdunensis breakpoints, the categorical agreement (CA) for two brands of Muller-Hinton agars, MH-II (Becton Dickinson) and MH-E (bioMérieux) were both 96.0%; MEs were both 0%; and VMEs were 19.4 and 12.9%, respectively. The new oxacillin agar reliably differentiated mecA -positive and mecA -negative isolates (100% CA) without any ME or VME results. The 8 isolates with false susceptibility in the cefoxitin DD testing had cefoxitin and oxacillin MICs in the susceptible range. The isolates showed heterogeneous oxacillin resistance with resistant subpopulations at low frequencies. All had positive PBP2a results and were typed as sequence type 27/SCC mec V. The findings highlight the inability of cefoxitin DD and MIC tests for reliable detection of some mecA -positive S. lugdunensis isolates., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ho, Law, Liu, Lau, Tong, Chow, Wu, Tse, Cheng and Que.)

In addition to human cases, cases of COVID-19 in captive animals and pets are increasingly reported. This raises the concern for two-way COVID-19 transmission between humans and animals. Here, we developed a SARS-CoV-2 nucleocapsid protein-based competitive enzyme-linked immunosorbent assay (cELISA) for serodiagnosis of COVID-19 which can theoretically be used in virtually all kinds of animals. We used 187 serum samples from patients with/without COVID-19, laboratory animals immunized with inactive SARS-CoV-2 virions, COVID-19-negative animals, and animals seropositive to other betacoronaviruses. A cut-off percent inhibition value of 22.345% was determined and the analytical sensitivity and specificity were found to be 1:64-1:256 and 93.9%, respectively. Evaluation on its diagnostic performance using 155 serum samples from COVID-19-negative animals and COVID-19 human patients showed a diagnostic sensitivity and specificity of 80.8% and 100%, respectively. The cELISA can be incorporated into routine blood testing of farmed/captive animals for COVID-19 surveillance.

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10 -3 substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.

Since the outbreak of COVID-19 in December 2019, there had been global shortage of personal protective equipment (PPE) supply due to the breakage of supply chain and also the forbidding of PPE exported by various countries. This situation had greatly affected the healthcare services in local hospitals of Hong Kong. To maintain the availability of PPE for healthcare workers in high-risk clinical settings, the cluster management of New Territories West Cluster, Hospital Authority, had implemented a bundle of interventions in controlling and managing the PPE consumption and ensuring its proper use. A Taskforce on Management of PPE was set up in February 2020 with the aim to monitor and manage the use of PPE in five local hospitals and eight general outpatient clinics of New Territories West Cluster, which were governed in a cluster basis, under the COVID-19 epidemic. Interventions including cutting down non-essential services, implementing telecare, monitoring PPE consumption at unit level and PPE stock at the Cluster Central Distribution Centre and forming mobile infection teams were implemented. The updated PPE standards and usage guidelines to clinical staff were promulgated through forums, newsletters and unit visits. The PPE consumption rates of individual unit were reviewed. Significant decrease in PPE consumption rates was noted when comparing with the baseline data. Comparing the data between 20 February and 1 June 2020, the overall PPE consumption rates were reduced by 64% (r=-0.841; p<0.001) while the PPE consumption rates in anaesthesia and operating theatres, and isolation and surveillance wards were reduced by 47% (r=-0.506; p=0.023) and 49% (r=-0.810; p<0.001), respectively. A bundled approach, including both administrative measures and staff education, is effective in managing PPE consumption during major infection outbreaks especially when PPE supply is at risk., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

To control the COVID-19 pandemic and prevent its resurgence in areas preparing for a return of economic activities, a method for a rapid, simple, and inexpensive point-of-care diagnosis and mass screening is urgently needed. We developed and evaluated a one-step colorimetric reverse-transcriptional loop-mediated isothermal amplification assay (COVID-19-LAMP) for detection of SARS-CoV-2, using SARS-CoV-2 isolate and respiratory samples from patients with COVID-19 ( n = 223) and other respiratory virus infections ( n = 143). The assay involves simple equipment and techniques and low cost, without the need for expensive qPCR machines, and the result, indicated by color change, is easily interpreted by naked eyes. COVID-19-LAMP can detect SARS-CoV-2 RNA with detection limit of 42 copies/reaction. Of 223 respiratory samples positive for SARS-CoV-2 by qRT-PCR, 212 and 219 were positive by COVID-19-LAMP at 60 and 90 min (sensitivities of 95.07% and 98.21%) respectively, with the highest sensitivities among nasopharyngeal swabs (96.88% and 98.96%), compared to sputum/deep throat saliva samples (94.03% and 97.02%), and throat swab samples (93.33% and 98.33%). None of the 143 samples with other respiratory viruses were positive by COVID-19-LAMP, showing 100% specificity. Samples with higher viral load showed shorter detection time, some as early as 30 min. This inexpensive, highly sensitive and specific COVID-19-LAMP assay can be useful for rapid deployment as mobile diagnostic units to resource-limiting areas for point-of-care diagnosis, and for unlimited high-throughput mass screening at borders to reduce cross-regional transmission.

Case: Coronavirus disease 2019 (COVID-19) is a pandemic respiratory disease. Patients typically present with fever, cough, and radiological lung changes. However, a significant proportion of these patients are asymptomatic. To date, we have limited information on the operations performed on these patients. We report our experience of a relatively asymptomatic elderly patient who underwent surgery for a hip fracture and was confirmed postoperatively to have COVID-19., Conclusion: Meticulous hand hygiene and use of surgical mask in daily practice is crucial to protect against asymptomatic and undiagnosed patients.

Background: Effective antiviral therapy is important for tackling the coronavirus disease 2019 (COVID-19) pandemic. We assessed the efficacy and safety of combined interferon beta-1b, lopinavir-ritonavir, and ribavirin for treating patients with COVID-19., Methods: This was a multicentre, prospective, open-label, randomised, phase 2 trial in adults with COVID-19 who were admitted to six hospitals in Hong Kong. Patients were randomly assigned (2:1) to a 14-day combination of lopinavir 400 mg and ritonavir 100 mg every 12 h, ribavirin 400 mg every 12 h, and three doses of 8 million international units of interferon beta-1b on alternate days (combination group) or to 14 days of lopinavir 400 mg and ritonavir 100 mg every 12 h (control group). The primary endpoint was the time to providing a nasopharyngeal swab negative for severe acute respiratory syndrome coronavirus 2 RT-PCR, and was done in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT04276688., Findings: Between Feb 10 and March 20, 2020, 127 patients were recruited; 86 were randomly assigned to the combination group and 41 were assigned to the control group. The median number of days from symptom onset to start of study treatment was 5 days (IQR 3-7). The combination group had a significantly shorter median time from start of study treatment to negative nasopharyngeal swab (7 days [IQR 5-11]) than the control group (12 days [8-15]; hazard ratio 4·37 [95% CI 1·86-10·24], p=0·0010). Adverse events included self-limited nausea and diarrhoea with no difference between the two groups. One patient in the control group discontinued lopinavir-ritonavir because of biochemical hepatitis. No patients died during the study., Interpretation: Early triple antiviral therapy was safe and superior to lopinavir-ritonavir alone in alleviating symptoms and shortening the duration of viral shedding and hospital stay in patients with mild to moderate COVID-19. Future clinical study of a double antiviral therapy with interferon beta-1b as a backbone is warranted., Funding: The Shaw-Foundation, Richard and Carol Yu, May Tam Mak Mei Yin, and Sanming Project of Medicine., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Three bacterial strains, HKU70 T , HKU71 T and HKU72 T , were isolated from the conjunctival swab, blood and sputum samples of three patients with conjunctivitis, bacteraemia and respiratory infection, respectively, in Hong Kong. The three strains were aerobic, Gram-stain positive, catalase-positive, non-sporulating and non-motile bacilli and exhibited unique biochemical profiles distinguishable from currently recognized Tsukamurella species. 16S rRNA, secA , rpoB and groEL gene sequence analyses revealed that the three strains shared 99.6-99.9, 94.5-96.8, 95.7-97.8 and 97.7-98.9 % nucleotide identities with their corresponding closest Tsukamurella species respectively. DNA-DNA hybridization confirmed that they were distinct from other known species of the genus Tsukamurella (26.2±2.4 to 36.8±1.2 % DNA-DNA relatedness), in line with results of in silico genome-to-genome comparison (32.2-40.9 % Genome-to-Genome Distance Calculator and 86.3-88.9 % average nucleotide identity values]. Fatty acids, mycolic acids, cell-wall sugars and peptidoglycan analyses showed that they were typical of members of Tsukamurella . The G+C content determined based on the genome sequence of strains HKU70 T , HKU71 T and HKU72 T were 69.9, 70.2 and 70.5 mol%, respectively. Taken together, our results supported the proposition and description of three new species, i.e. Tsukamurella sputi HKU70 T (=JCM 33387 T =DSM 109106 T ) sp. nov., Tsukamurella asaccharolytica HKU71 T (=JCM 33388 T =DSM 109107 T ) sp. nov. and Tsukamurella conjunctivitidis HKU72 T (=JCM 33389 T =DSM 109108 T ) sp. nov.

Objective: To determine the efficacy of 2 types of antimicrobial privacy curtains in clinical settings and the costs involved in replacing standard curtains with antimicrobial curtains., Design: A prospective, open-labeled, multicenter study with a follow-up duration of 6 months., Setting: This study included 12 rooms of patients with multidrug-resistant organisms (MDROs) (668 patient bed days) and 10 cubicles (8,839 patient bed days) in the medical, surgical, neurosurgical, orthopedics, and rehabilitation units of 10 hospitals., Method: Culture samples were collected from curtain surfaces twice a week for 2 weeks, followed by weekly intervals., Results: With a median hanging time of 173 days, antimicrobial curtain B (quaternary ammonium chlorides [QAC] plus polyorganosiloxane) was highly effective in reducing the bioburden (colony-forming units/100 cm2, 1 vs 57; P < .001) compared with the standard curtain. The percentages of MDRO contamination were also significantly lower on antimicrobial curtain B than the standard curtain: methicillin-resistant Staphylococcus aureus, 0.5% vs 24% (P < .001); carbapenem-resistant Acinetobacter spp, 0.2% vs 22.1% (P < .001); multidrug-resistant Acinetobacter spp, 0% vs 13.2% (P < .001). Notably, the median time to first contamination by MDROs was 27.6 times longer for antimicrobial curtain B than for the standard curtain (138 days vs 5 days; P = .001)., Conclusions: Antimicrobial curtain B (QAC plus polyorganosiloxane) but not antimicrobial curtain A (built-in silver) effectively reduced the microbial burden and MDRO contamination compared with the standard curtain, even after extended use in an active clinical setting. The antimicrobial curtain provided an opportunity to avert indirect costs related to curtain changing and laundering in addition to improving patient safety.

Although Tsukamurella infections have been increasingly reported in Europe, Asia, America, and Africa, indicating that diseases caused by this group of bacteria are emerging in a global scale, species identification within this genus is difficult in most clinical microbiology laboratories. Recently, we showed that groEL gene sequencing is useful for identification of all existing Tsukamurella species. Nevertheless, PCR sequencing is still considered expensive, time-consuming, and technically demanding, and therefore is yet to be incorporated as a routine identification method in clinical laboratories. Using groEL gene sequencing as the reference method, 60 Tsukamurella isolates were identified as five different Tsukamurella species [T. tyrosinosolvens (n = 31), T. pulmonis (n = 25), T. hongkongensis (n = 2), T. strandjordii (n = 1), and T. sinensis (n = 1)]. The most common source of the patient isolates were the eye (n = 18), sputum (n = 6), and blood (n = 6). None of the 60 isolates were identified correctly to species level by MALDI-TOF MS with the original Bruker database V.6.0.0.0. Using the Bruker database extended with 15 type and reference strains which covered all the currently recognized 11 Tsukamurella species, 59 of the 60 isolates were correctly identified to the species level with score ≥2.0. MALDI-TOF MS should be useful for routine species identification of Tsukamurella in clinical microbiology laboratories after optimization of the database. T. tyrosinosolvens was the most common species observed in patients with Tsukamurella infections and the predominant species associated with ocular infections.

Rapid and accurate detection of carbapenemase-producing Enterobacteriaceae (CPE) is important for preventing their spread in health care settings. We compared the performance of the Carba NP (CNP) test using the CLSI tube method with that using a modified paper strip method for the detection of carbapenemases in 390 Enterobacteriaceae isolates. The isolates were identified by Hong Kong's carbapenem-resistant Enterobacteriaceae surveillance program in 2016 and comprised 213 CPE and 177 carbapenemase-negative Enterobacteriaceae isolates. Molecular genotype was used as the reference. The test results were read at different time points for the CLSI method (1 min, 5 min, 1 h, and 2 h) and strip method (1 min and 5 min). The strip CNP and CLSI CNP tests correctly detect carbapenemase production in 93% and 93% of KPC producers, 100% and 38% of IMI producers, 94% and 85% of IMP producers, 98% and 90% of NDM producers, and 29% and 12% of OXA producers, respectively. Overall, the strip method has superior sensitivity to the CLSI method (86% versus 75%, respectively; P < 0.001, McNemar test). The specificity of both methods was 100%. By the CLSI method, 27%, 14%, 29%, and 6% of the CPE isolates were positive at 1 min, 5 min, 1 h, and 2 h, respectively. In contrast, by the strip method, 76% of the CPE isolates were positive at 1 min, and an additional 10% were positive at 5 min. In conclusion, the Carba NP test by use of the modified strip method has a higher sensitivity and a shorter assay time than that those by use of the CLSI tube method., (Copyright © 2017 American Society for Microbiology.)

We determined the susceptibilities of 57 Talaromyces marneffei strains to anidulafungin, itraconazole, voriconazole, and posaconazole with MICs of 2 to 8, 0.002 to 0.004, 0.016 to 0.063, and 0.001 to 0.002 μg/ml by broth microdilution and >32, ≤0.002 to 0.008, ≤0.002 to 0.008, and ≤0.002 μg/ml by Etest, respectively, at yeast phase; MICs at mycelial phase for anidulafungin and posaconazole were 1 to 2 and 0.004 to 0.063 μg/ml, respectively. The results suggest promising activities of posaconazole. Etest can be used for testing of azoles against T. marneffei ., (Copyright © 2017 American Society for Microbiology.)

Objectives: To characterize bla IMP-4 -carrying plasmids originating from inpatients in Hong Kong., Methods: Sixteen bla IMP-4 -carrying plasmids identified among Enterobacteriaceae (nine Escherichia coli, four Klebsiella pneumoniae, two Citrobacter freundii and one Enterobacter cloacae) recovered from 15 patients were characterized. The isolates, collected during January 2010 to December 2013, were retrospectively investigated by plasmid sequencing, molecular and fitness studies., Results: The bla IMP-4 -carrying plasmids belonged to the IncN ST7 lineage (∼50 kb). Twelve of the 16 plasmids were epidemiologically linked to seven different regions in China. Alignment of the complete plasmid sequences showed identical plasmid backbones and two highly similar resistance regions, each carrying one of two resistance genes (bla IMP-4 and qnrS1). The bla IMP-4 was detected in a class 1 integron (containing bla IMP-4 and intron Kl.pn.13) that is part of an IS6100-IS26 transposon-like structure. The nine E. coli carrying the epidemic plasmid belonged to multiple multilocus STs (six ST542, one ST131, one ST657 and one ST3177). Fitness assays performed on E. coli J53 recipients showed that the presence of the epidemic plasmid did not have a significant biological cost., Conclusions: This study identified a bla IMP-4 -carrying IncN ST7 plasmid disseminated among multiple enterobacterial species originating from patients with epidemiological links to different regions in China., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Two bacterial strains, HKU54T and HKU55, were isolated from the oral cavity of two Chinese cobras (Naja atra) in Hong Kong. 16S rRNA gene sequence analysis revealed 100 % sequence identity between HKU54T and HKU55, and the two strains shared 99.0 % sequence identities with Tsukamurella inchonensis ATCC 700082T. The two strains had unique biochemical profiles distinguishable from closely related species of the genus Tsukamurella. DNA-DNA hybridization confirmed that they belonged to the same species (≥92.1±7.9 % DNA-DNA relatedness) but were distinct from all other known species of the genus Tsukamurella (≤52.6±5.3 % DNA-DNA relatedness). Chemotaxonomic and morphological analyses of the two strains also demonstrated results consistent with their classification in the genus Tsukamurella. The DNA G+C contents of strains HKU54T and HKU55 were 69.2±1.5 mol% and 69.2±1.3 mol% (mean±sd; n=3) respectively. A novel species, Tsukamurella serpentis sp. nov., is proposed to accommodate strains HKU54T and HKU55, with HKU54T (=JCM 31017T=DSM 100915T) designated as the type strain.

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.

Recently, we reported the isolation of Streptobacillus hongkongensis sp. nov. from patients with quinsy or septic arthritis. In this study, we developed a PCR sequencing test after sulfamethoxazole/trimethoprim and nalidixic acid enrichment for detection of S. hongkongensis. During a three-month study period, among the throat swabs from 132 patients with acute pharyngitis and 264 controls, PCR and DNA sequencing confirmed that S. hongkongensis and S. hongkongensis-like bacteria were detected in 16 patients and 29 control samples, respectively. Among these 45 positive samples, five different sequence variants were detected. Phylogenetic analysis based on the 16S rRNA gene showed that sequence variant 1 was clustered with S. hongkongensis HKU33(T)/HKU34 with high bootstrap support; while the other four sequence variants formed another distinct cluster. When compared with the 16S rRNA gene of S. hongkongensis HKU33(T), the five sequence variants possessed 97.5-100% sequence identities. Among sequence variants 2-5, their sequences showed ≥99.5% nucleotide identities to each other. Forty-two individuals (93.3%) only harbored one sequence variant. We showed that the human oropharynx is a reservoir of S. hongkongensis, but the bacterium is not associated with acute pharyngitis. Another undescribed novel Streptobacillus species is probably also residing in the human oropharynx.

Background: Penicillium marneffei is the most important thermal dimorphic fungus causing systemic mycosis in HIV-infected and other immunocompromised patients in Southeast Asia. However, laboratory diagnosis of penicilliosis, which relies on microscopic morphology and mycelial-to-yeast conversion, is time-consuming and expertise-dependent, thus delaying diagnosis and treatment. Although matrix -assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is useful for identification of various medically important fungi, its performance for identification of P. marneffei is less clear., Results: We evaluated the performance of the Bruker MALDI-TOF MS system for identification of mold and yeast cultures of 59 clinical strains and the type strain of P. marneffei using the direct transfer method, with results compared to four phylogenetically closely related species, P. brevi-compactum, P. chrysogenum, Talaromyces aurantiacus and T. stipitatus. Using the Bruker original database combined with BDAL v4.0.0.1 and Filamentous Fungi Library 1.0, MALDI-TOF MS failed to identify the 60 P. marneffei strains grown in mold and yeast phase (identified as P. funiculosum and P. purpurogenum with scores <1.7 respectively). However, when the combined database was expanded with inclusion of spectra from 21 P. marneffei strains in mold and/or yeast phase, all the remaining 39 P. marneffei strains grown in mold or phase were correctly identified to the species level with score >2.0. The MS spectra of P. marneffei exhibited significant difference to those of P. brevi-compactum, P. chrysogenum, T. aurantiacus and T. stipitatus. However, MALDI-TOF MS failed to identify these four fungi to the species level using the combined database with or without spectra from P. marneffei., Conclusions: MALDI-TOF MS is useful for rapid identification of both yeast and mold cultures of P. marneffei and differentiation from related species. However, accurate identification to the species level requires database expansion using P. marneffei strains.

Background: Long-term outcomes in non-HIV immunocompromised patients with disseminated Mycobacterium avium complex (dMAC) infections are unknown and the need for post-treatment secondary prophylaxis against MAC is uncertain in this setting. The objective of this study was to determine the need of continuing secondary anti-MAC prophylaxis in non-HIV patients after completing treatment of the primary dMAC episode., Methods: We conducted a ten-year multi-center analysis of non-HIV immunosuppressed patients with dMAC infections in Hong Kong., Results: We observed sixteen patients with dMAC during the study period of which five (31 %) were non-HIV immunosuppressed patients. In the non-HIV immunosuppressed group, three patients completed a treatment course without secondary prophylaxis, one patient received azithromycin-based secondary prophylaxis and one patient was still receiving therapy for the first dMAC episode. All the three patients who completed treatment without being given secondary prophylaxis developed recurrent dMAC infection requiring retreatment., Conclusions: In view of the high rate of dMAC infection recurrence in non-HIV immunocompromised patients following treatment completion, our data support long-term anti-MAC suppression therapy after treatment of the first dMAC infection episode in immunocompromised non-HIV patients, as is recommended for patients with advanced HIV. Tests of cell mediated immune function need to be evaluated to guide prophylaxis discontinuation in non-HIV patients.

Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

While morphological examination is the most widely used for Aspergillus identification in clinical laboratories, PCR-sequencing and MALDI-TOF MS are emerging technologies in more financially-competent laboratories. However, mycological expertise, molecular biologists and/or expensive equipment are needed for these. Recently, artificial intelligence (AI), especially image recognition, is being increasingly employed in medicine for fast and automated disease diagnosis. We explored the potential utility of AI in identifying Aspergillus species. In this proof-of-concept study, using 2813, 2814 and 1240 images from four clinically important Aspergillus species for training, validation and testing, respectively; the performances and accuracies of automatic Aspergillus identification using colonial images by three different convolutional neural networks were evaluated. Results demonstrated that ResNet-18 outperformed Inception-v3 and DenseNet-121 and is the best algorithm of choice because it made the fewest misidentifications ( n  = 8) and possessed the highest testing accuracy (99.35%). Images showing more unique morphological features were more accurately identified. AI-based image recognition using colonial images is a promising technology for Aspergillus identification. Given its short turn-around-time, minimal demand of expertise, low reagent/equipment costs and user-friendliness, it has the potential to serve as a routine laboratory diagnostic tool after the database is further expanded.

Previous work on the subclones within Escherichia coli ST131 predominantly involved isolates from Western countries. This study assessed the prevalence and antimicrobial resistance attributed to this clonal group. A total of 340 consecutive, non-duplicated urinary E. coli isolates originating from four clinical laboratories in Hong Kong in 2013 were tested. ST131 prevalence among the total isolates was 18.5 % (63/340) and was higher among inpatient isolates (23.0 %) than outpatient isolates (11.8 %, P<0.001), and higher among isolates from patients aged ≥65 years than from patients aged 18-50 years and 51-64 years (25.4 vs 3.4 and 4.0 %, respectively, P<0.001). Of the 63 ST131 isolates, 43 (68.3 %) isolates belonged to the H30 subclone, whereas the remaining isolates belonged to H41 (n = 17), H54 (n = 2) and H22 (n = 1). All H30 isolates were ciprofloxacin-resistant, of which 18.6 % (8/43) belonged to the H30-Rx subclone. Twenty-six (41.3 %) ST131 isolates were ESBL-producers, of which 19 had blaCTX-M-14 (12 non-H30-Rx, two H30-Rx and five H41), six had blaCTX-M-15 (five non-H30-Rx and one H30-Rx) and one was blaCTX-M-negative (H30). In conclusion, ST131 accounts for a large share of the antimicrobial-resistant E. coli isolates from geriatric patients. Unlike previous reports, ESBL-producing ST131 strains mainly belonged to non-H30-Rx rather than the H30-Rx subclone, with blaCTX-M-14 as the dominant enzyme type., (© 2015 The Authors.)

Background: Emerging human picornaviruses, including human parechovirus (HPeV), Aichi virus (AiV) and salivirus (SalV) were found to be associated with gastroenteritis, but their roles in enteric infections are not fully understood. In addition, no report on the circulation of these viruses in Hong Kong is available. The objective of this study was to investigate the prevalence and genetic diversity of HPeV, AiV and SalV in fecal samples from hospitalized children with gastroenteritis in Hong Kong., Methods: Fecal samples from hospitalized children with gastroenteritis were subject to detection of HPeV, AiV and SalV by RT-PCR using consensus primers targeted to their 5'UTRs. Positive samples were subject to capsid and/or 3CD region analysis for genotype determination. The epidemiology of HPeV, AiV and SalV infections was analyzed., Results: Among 1,708 fecal samples subjected to RT-PCR using primers targeted to 5'UTR of HPeV, AiV and SalV, viruses were detected in 55 samples, with 50 positive for HPeV only, 3 positive for AiV only, 1 positive for both HPeV and AiV, and 1 positive for both HPeV and SalV. Phylogenetic analysis of the partial VP1 gene of the 33 HPeV strains revealed the presence of genotypes of HPeV- 1, 3, 4, 5, 7, 10, among which HPeV-1 was the predominant genotype circulating in our population. The peak activity of HPeV infection was in fall. Of the 3 children with AiV infection, the 3 AiV strains were found to belong to genotype A based on the phylogenetic analysis of their partial VP1 and 3CD regions. The genotype of a SalV strain detected in this study could not be determined. Co-detection of different pathogens was observed in 24 samples (43.6%) of 55 fecal samples positive for HPeV, AiV and SalV., Conclusions: HPeV, AiV and SalV were detected in fecal samples of hospitalized children with gastroenteritis in Hong Kong, with the former having the highest prevalence. HPeV-1 was the predominant genotype among HPeVs, while genotype A was the predominant genotype among AiVs in this study.

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., (Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.)

We compared a novel selective Staphylococcus lugdunensis (SSL) medium with routine media (blood and chocolate agars) for the detection of S. lugdunensis in 990 clinical specimens (from tissue, pus, or wound swabs). Significantly more S. lugdunensis isolates were detected on SSL medium (34/990) than on routine medium (7/990) (P = 0.001, McNemar's test)., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

The IncA/C plasmids are broad host-range vehicles which have been associated with wide dissemination of CMY-2 among Enterobacteriaceae of human and animal origins. Acquired metallo-β-lactamases (MBLs) such as the IMP-type enzymes are increasingly reported in multidrug-resistant Gram-negative bacteria worldwide, particularly in Enterobacteriaceae. We described the complete sequence of the first IMP-4-encoding IncA/C2 plasmid, pIMP-PH114 (151,885 bp), from a sequence type 1 Klebsiella pneumoniae strain that was recovered from a patient who was hospitalized in the Philippines. pIMP-PH114 consists of a backbone from the IncA/C2 plasmids, with the insertion of a novel Tn21-like class 1 integron composite structure (containing the cassette array bla IMP-4-qacG-aacA4-catB3, followed by a class C β-lactamase bla DHA-1 and the mercury resistance operon, merRTPCADE) and a sul2-floR encoding region. Phylogenetic analysis of the IncA/C repA sequences showed that pIMP-PH114 formed a subgroup with other IncA/C plasmids involved in the international spread of CMY-2, TEM-24 and NDM-1. Identical bla IMP-4 arrays have been described among different Enterobacteriaceae and Acinetobacter spp. in China, Singapore and Australia but the genetic context is different. The broad host range of IncA/C plasmids may have facilitated dissemination of the bla IMP-4 arrays among different diverse groups of bacteria.

Objective: To determine the prevalence, risk factors, and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) colonization at the time of admission to acute medical units and to develop a cost-effective screening strategy., Methods: Nasal and groin screening cultures were performed for patients at admission to 15 acute medical units in all 7 catchment regions in Hong Kong. All MRSA isolates were subjected to spa typing., Results: The overall carriage rate of MRSA was 14.3% (95% confidence interval [CI], 13.5-15.1). MRSA history within the past 12 months (adjusted odds ratio [OR], 4.60 [95% CI, 3.28-6.44]), old age home residence (adjusted OR, 3.32 [95% CI, 2.78-3.98]), and bed-bound state (adjusted OR, 2.19 [95% CI, 1.75-2.74]) were risk factors selected as MRSA screening criteria that provided reasonable sensitivity (67.4%) and specificity (81.8%), with an affordable burden (25.2%). spa typing showed that 89.5% (848/948) of the isolates were clustered into the 4 spa clonal complexes (CCs): spa CC1081, spa CC032, spa CC002, and spa CC4677. Patients colonized with MRSA spa types t1081 (OR, 1.77 [95% CI, 1.49-2.09]) and t4677 (OR, 3.09 [95% CI, 1.54-6.02]) were more likely to be old age home residents., Conclusions: MRSA carriage at admission to acute medical units was prevalent in Hong Kong. Our results suggest that targeted screening is a pragmatic approach to increase the detection of the MRSA reservoir. Molecular typing suggests that old age homes are epicenters in amplifying the MRSA burden in acute hospitals. Enhancement of infection control measures in old age homes is important for the control of MRSA in hospitals.

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.

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization is crucial for the prevention and control of MRSA infections in health care settings. The LightCycler MRSA Advanced Test (Roche Diagnostics) is a commercially available real-time PCR assay for direct detection of MRSA nasal colonization by targeting of the staphylococcal cassette chromosome mec (SCCmec)-orfX junction. The diagnostic performance of the assay was compared with that of ChromID MRSA agar (bioMérieux) culture and an in-house duplex real-time PCR assay. Among 1,246 nasal swab specimens collected from 2 general hospitals in Hong Kong, 174 (14%) were considered true positive for MRSA. Chromogenic culture and the in-house real-time PCR assay identified 147 (84.5%) and 133 (76.4%) true-positive cases with specificities of 100% and 98.6%, respectively. Based on the target melting temperature (Tm) values (57.0 to 62.0 °C) defined by the manufacturer, the LightCycler MRSA Advanced Test identified only 85 (48.9%) true-positive specimens. Interestingly, an additional 60 (34.5%) true-positive specimens were detected despite atypical Tm values of 55 °C, providing overall sensitivity and specificity values of 83.3% and 99%, respectively. Among isolates with Tm values of 55 °C, most were typed as clonal complex 45 (CC45). By sequence analysis of the SCCmec-orfX junction, characteristic single-nucleotide polymorphisms (SNPs) were identified only in isolates with Tm values of 55°C and not in those with typical Tm values. It is conceivable that those SNPs were located inside the target region of the proprietary hybridization probes, which resulted in a Tm shift in the melting curve analysis. Our study highlights the importance of a global evaluation of commercial kits so that the interpretation algorithm covers different lineages of MRSA clones prevalent in various geographical regions.

The New Delhi metallo-β-lactamase (NDM-1) is one of the most important resistance traits in Enterobacteriaceae. We characterized nine bla NDM-1 producing Enterobacteriaceae recovered from seven patients who have recently travelled or been treated in India (n=1) or mainland China (n=6) during December 2010-May 2012. All the China-linked patients had no links to the Indian subcontinent. The bla NDM-1 carrying plasmids belonged to the novel IncX3 (∼50 kb, in seven isolates including two Escherichia coli, two Klebsiella pneumoniae, one Citrobacter freundii, one Enterobacter aerogenes and one E. cloacae), IncA/C2 (∼140 kb, in one E. coli) or FII-F1B groups (∼110 kb, in one E. coli). Restriction fragment length polymorphism analysis of the seven IncX3 plasmids revealed identical pattern in six and two bands difference in the remaining one. The IncX3 plasmids carrying bla NDM-1 were epidemiologically linked to Guangzhou (n=1), Hunan (n=4), Haifeng (n=1) and Dongguan (n=1) in mainland China. Complete sequencing of the IncX3 plasmid pNDM-HN380 revealed that it was 54 035 bp long and encoded 52 open reading frames. The bla NDM-1 gene was found in a transposon-like structure flanked by ISAba125 and IS26, inserted into the plasmid genetic load region. The sequences of the bla NDM-1 containing module within the two IS elements were identical to those previously described for bla NDM-1-positive Tn125 in the plasmids or chromosome of Acinetobacter isolates. In summary, this is the first description of IncX3 plasmids carrying bla NDM-1. The findings indicate the worrisome involvement of an epidemic plasmid in the dissemination of NDM-1 in China.

We report the first case of severe pneumonia due to co-infection with the emerging avian influenza A (H5N1) virus subclade 2.3.2.1 and Mycoplasma pneumoniae. The patient was a returning traveller who had visited a poultry market in South China. We then review the epidemiology, virology, interspecies barrier limiting poultry-to-human transmission, clinical manifestation, laboratory diagnosis, treatment and control measures of H5N1 clades that can be transmitted to humans. The recent controversy regarding the experiments involving aerosol transmission of recombinant H5N1 virus between ferrets is discussed. We also review the relative contribution of the poor response to antiviral treatment and the virus-induced hyperinflammatory damage to the pathogenesis and the high mortality of this infection. The factors related to the host, virus or medical intervention leading to the difference in disease mortality of different countries remain unknown. Because most developing countries have difficulty in instituting effective biosecurity measures, poultry vaccination becomes an important control measure. The rapid evolution of the virus would adversely affect the efficacy of poultry vaccination unless a correctly matched vaccine was chosen, manufactured and administered in a timely manner. Vigilant surveillance must continue to allow better preparedness for another poultry or human pandemic due to new viral mutants.

Catabacter hongkongensis is a recently described catalase-positive, motile, anaerobic, nonsporulating, Gram-positive coccobacillus that was first isolated from blood cultures of four patients from Hong Kong and Canada. Although DNA sequences representing C. hongkongensis have been detected in environmental sources, only one additional case of human infection has been reported, in France. We describe five cases of C. hongkongensis bacteremia in Hong Kong, two presenting with sepsis, one with acute gangrenous perforated appendicitis, one with acute calculous cholecystitis, and one with infected carcinoma of colon. Three patients, with gastrointestinal malignancy, died during admission. All five isolates were catalase positive, motile, and negative for indole production and nitrate reduction and produced acid from arabinose, glucose, mannose, and xylose. They were unambiguously identified as C. hongkongensis by 16S rRNA gene analysis. Of the total of 10 reported cases of C. hongkongensis bacteremia in the literature and this study, most patients had underlying diseases, while two cases occurred in healthy young individuals with acute appendicitis. Six patients presented with infections associated with either the gastrointestinal or biliary tract, supporting the gastrointestinal tract as the source of bacteremia. C. hongkongensis bacteremia is associated with a poor prognosis, with a high mortality of 50% among reported cases, especially in patients with advanced malignancies. All reported isolates were susceptible to metronidazole. Identification of more C. hongkongensis isolates by 16S rRNA gene sequencing will help better define its epidemiology and pathogenesis.