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Timeline of events from initiation of chemotherapy treatment to time of publication #1Course 1 induction chemotherapy (MEC) with mitoxantrone 25 mg/m2, etoposide 750 mg/m2 and cytarabine 2800 mg/m2 administered. #2Course 2 induction chemotherapy (ADxE) with cytarabine 1400 mg/m2, daunorubicin 180 mg/m2, and etoposide 450 mg/m2 administered. #3Oral thioguinine 120 mg/m2 daily was given for total of 18 days (intended for total of 28 days in a 4-week cycle), IV cytarabine 75 mg/m2 daily was given on Days 1–4 and 15–18 of the 4-weekly cycle (a total of eight doses were given and then withheld due to infection). A single dose of IT cytarabine 40 mg was given 1 day prior to start of the 4-week cycle of chemotherapy. ○1Day 29 marrow confirmed remission status with MRD < 0.1% ○2Day 40 marrow before course-2 induction chemotherapy continued in remission with MRD < 0.1% ○3Bone marrow aspiration performed 2 weeks after completion of one course of low-dose bridging chemotherapy (prior to consideration of starting consolidation chemotherapy) confirmed persistent remission status with MRD < 0.1% ○4Regular 4-weekly bone marrow aspiration confirmed remission with MRD < 0.1% ○5Regular 4-weekly bone marrow aspiration confirmed remission with MRD < 0.1% ◼1MRI of right lower limb revealed bilateral shotty groin lymph nodes (LNs), largest 1.6 cm at the right groin and 1 cm at the right popliteal fossa, accompanied with subcutaneous edema over the right upper medial and posterior distal thigh (Figure 1 A). Neutrophil and monocyte counts were always less than 1 × 109/L and 0.2 × 109/L, respectively. ◼2MRI of the groin and right ankle showed abscess at the right groin and lateral aspect of the right ankle with underlying osteomyelitis of calcaneus (Figure 1 B). ◼3MRI of bilateral lower limbs showed interval improvement in inflammatory changes over the bilateral femur, tibia, and right calcaneus ◼4MRI of hips showed mild synovitis ◼5MRI of the right ankle showed minimal residual inflammatory changes at the right calcaneus BxUltrasound-guided aspiration and biopsy were performed, which yielded granulomas with surrounding suppurative inflammation (Figure 1 C). A moderate number of AFB was highlighted on aspirate sample. Neutrophil and monocyte counts recovered. ◆1PET-CT showed abscesses in right posterior thigh and popliteal fossa (maximum standard uptake value [SUV max ] 3.8), right calcaneal osteomyelitis (SUV max 9.4), as well as multiple hypermetabolic LN at the right groin (SUV max 6.5) extending to the right internal iliac LN (Figure 1 D). ◆2PET-CT showed worsening of the right calcaneal osteomyelitis with increased bony lysis ◆3PET-CT showed residual infective focus at the right calcaneus with interval reduction in metabolic activity over the right groin and right popliteal fossa ◆4PET-CT showed resolution of right groin lymphadenopathy and right popliteal fossa subcutaneous lesion, also decreased metabolic activity at the right calcaneus §1First operation on calcaneal bone excision and debridement of the right ankle §2Second operation involving I&D of the right groin and popliteal abscesses along with debridement of the right ankle soft tissue §3Third operation on sequestrectomy of the right calcaneus and insertion of antibiotic-infused cement (vancomycin, amikacin, and gentamycin) §4Fourth operation on removal of antibiotic-infused cement and bone graft insertion. • Long-term disease remission achieved without relapse for 2 years. • Only two cycles of induction chemotherapy with one cycle of low-dose chemotherapy. • Successful treatment of patient using two drugs with limited data in the pediatric population (bedaquiline and clofazimine) when the patient was intolerable to first-line anti-mycobacterial agents. • Successful clearance of right calcaneal osteomyelitis and subcutaneous abscesses with multiple operations and antibiotic-infused cement. Normal limb function and activities. Our patient was a 4-year-old female with acute myeloid leukemia complicated with right calcaneal osteomyelitis due to Mycobacterium abscessus with subcutaneous abscesses extending to the popliteal and groin regions after two courses of induction chemotherapy according to NOPHO-AML 2012 protocol. She required multiple operations and prolonged anti-mycobacterial therapy. A high index of suspicion for mycobacterial infection is required for immunocompromised patients with prolonged fever or unusual presentation. Mycobacterial osteomyelitis is rare, difficult to diagnose and treat, and may necessitate prolonged interruption of anti-leukemic therapy. Multidisciplinary collaboration in patient management is crucial. Long-term toxicity of antimicrobials with uncertain efficacy should not be overlooked. [ABSTRACT FROM AUTHOR]

This study used a recently developed EUCAST disc diffusion method to measure the susceptibility of 741 B. fragilis group isolates to six antibiotics. Isolates nonsusceptible to imipenem and metronidazole by the disc method were further investigated by E-test. Species identification was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), PCR assays and 16S rRNA sequencing. The most common species were B. fragilis (n = 424, including 81 division II and 343 division I isolates), B. thetaiotaomicron (n = 111), B. ovatus (n = 53) and B. vulgatus (n = 46). Overall, metronidazole following by imipenem and amoxicillin-clavulanate are the most active agents with over 90% of all the isolates being susceptible at the tentative disc breakpoints. Susceptibility rates for moxifloxacin (69.5%), piperacillin-tazobactam (58.2%) and clindamycin (37.2%) were much lower. Metronidazole is the only agent active against >90% of B. fragilis , non- fragilis Bacteroides and Parabacteroides isolates. With the exception of B. fragilis division II, imipenem was active against 88.0%–98.3% of isolates of the other species. Susceptibility rates for clindamycin (14.4%–54.3%) and moxifloxacin (33.3%–80.6%) were low across all species and many isolates had no inhibition zone around the discs. E-test testing confirmed 8.2% (61/741) and 1.6% (12/741) isolates as nonsusceptible to imipenem and metronidazole, respectively with B. fragilis and B. thetaoiotaomicron accounting for a large share of the observed resistance to both agents. Two imipenem-resistant and one metronidazole-resistant B. dorei were misidentified as B. vulgatus by MALDI-TOF MS. These data highlights the importance anaerobic susceptibility testing in clinical laboratories to guide therapy. [ABSTRACT FROM AUTHOR]

This study investigated 248 extended-spectrum β-lactamase-producing Escherichia coli isolates from 2012 to 2013 for hybrid bla CTX-M genes. bla CTX-M genes were detected in 228 isolates of which 14 isolates were hybrid bla CTX-M positive (6 bla CTX-M-123 , 6 bla CTX-M-64 , and 2 bla CTX-M-132 ). The 14 hybrid bla CTX-M –carrying isolates (8 from chickens, 2 each from pigs and cattle, 1 each from dog and rodent) were genetically diverse. All but 2 hybrid bla CTX-M were carried on IncI1 (5 bla CTX-M-123 ) and IncI2 (6 bla CTX-M-64 and one bla CTX-M-132 ) plasmids. Our IncI1 and IncI2 plasmids had pHNAH4-1–like and pHN1122-1–like restriction fragment length polymorphism patterns, respectively. Genetic relatedness of the plasmids to pHNAH4-1 and pHN1122-1 were confirmed by complete sequencing of 3 plasmids, pCTXM123_C0996, pCTXM64_C0967, and pCTXM132_P0421. Plasmids closely related to pHNAH4-1 and pHN1122-1 and carrying different bla CTX-M alleles have been reported from multiple geographic areas in China previously. The findings highlighted the wide dissemination of hybrid bla CTX-M variants in different parts of China. [ABSTRACT FROM AUTHOR]

This study assessed pneumococcal carriage in the early periods after routine use of 13-valent pneumococcal conjugate vaccine (PCV13) in Hong Kong. Nasopharyngeal swabs were obtained from 1110 children (<5 years) admitted with acute illness during September 2010–August 2013. Pneumococcal carriage rate was 13.5% in unvaccinated children, 14.1% in children who had ≥1 PCV dose and 15.3% in children who had ≥3 PCV doses. Nonv-PCV13 serotypes comprised 56.4% of all isolates. The most common serogroup/types were 15 (15A, 5.1%; 15B, 10.3%; 15C, 9.6%; 15F, 0.6%), 19F (17.9%), 6A (7.1%) and 6C (7.1%). Carriage of serogroup 15 was more common among vaccinated children (4.1% versus 0.6%, P = 0.033). Molecular typing revealed that expansion of several clones (clonal complex, CC63, CC199, CC1262, CC3397) was responsible for the increase in serogroup 15. Almost all CC63 and CC3397 isolates were nonsusceptible to both penicillin and erythromycin. The finding highlights the emergence of serogroup 15 following PCV13 use. [ABSTRACT FROM AUTHOR]

We collected nasal, axilla, and groin swabs from 252 adult patients from 2 nephrology centers in Hong Kong. Staphylococcus lugdunensis carriage was detected in 51.6% patients (groin, 39.3%; axilla, 19.8%; nose, 17.9%). The carriage rates of methicillin-sensitive S . lugdunensis and methicillin-resistant S . lugdunensis (MRSL) were 46.0% and 8.3%, respectively. Independent risk factors for S . lugdunensis carriage included male sex (odds ratio [OR], 4.4), hemodialysis (OR, 2.2), and aged 18–50 years (OR, 2.4). The isolates belonged to 10 pulsotype clusters (n = 129) and 8 singletons (n = 8). All MRSL and most gentamicin- and tetracycline-resistant strains were found in a predominating sequence type 3 clone, designated HKU1, which accounted for 51.8% of all colonizing S . lugdunensis strains. The 21 MRSL isolates had SCC mec type V (n = 18), type IV (n = 2), and type I (n = 1). The finding highlights the potential for dissemination of multidrug resistance through successful S . lugdunensis clones. [ABSTRACT FROM AUTHOR]

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/C 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/C plasmids, with the insertion of a novel Tn 21-like class 1 integron composite structure (containing the cassette array bla- qacG- aacA4- catB3, followed by a class C β-lactamase bla 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 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 arrays among different diverse groups of bacteria. [ABSTRACT FROM AUTHOR]

The IncX family of plasmids has recently been expanded to include at least four subtypes, IncX1-IncX4. The revised classification provides an opportunity for improving our understanding of the sequence diversity of the IncX plasmids and the resistance genes they carried. We described the complete nucleotide sequence of a novel IncX3 plasmid, pKPC-NY79 (42,447 bp) from a sequence-type 258 Klebsiella pneumoniae strain that was isolated from a patient who was hospitalized in New York, United States. In pKPC-NY79, the plasmid scaffold and genetic load region were highly similar to homologous regions in pIncX-SHV (IncX3, JN247852) and the bla carrying pKpQIL (IncFII, GU595196), respectively, indicating that it has possibly arisen through recombination of plasmids. The bla gene, as part of a transposon Tn 4401a, was found within the genetic load region. The backbone of pKPC-NY79 differs from pIncX-SHV by a deletion involving the gene tandem hns- topB (encoding H-NS protein and topoisomerase III, respectively) and a putative ATPase gene. Unexpectedly, the impact of the hns- topB deletion on host fitness and plasmid stability was found to be small. In conclusion, the findings contribute to a better understanding of the plasmid platforms carrying bla and of variations in the backbone of the IncX3 plasmids. [ABSTRACT FROM AUTHOR]

Abstract: This study assessed the temporal changes in the molecular epidemiology of bacteremic Escherichia coli isolates producing CTX-M-14 in Hong Kong. Blood isolates from 1996 to 1998 (period 1, n = 50) and 2007 to 2008 (period 2, n = 117) were investigated by molecular methods. CTX-M–type ESBL was carried by 98.2% (164/167) of the isolates. In both periods, the CTX-M-9 group and CTX-M-14 allele were the predominant ESBL type. The major clones were found to change from ST68 and ST405 in period 1 to ST131, ST69, and ST12 in period 2. Among 65 CTX-M-14–producing plasmids investigated further, 54 had the FII replicon. Replicon sequence typing and plasmid polymerase chain reaction–restriction fragment length polymorphism showed that 79.6% (43/54) of the FII plasmid subset was similar to the completely sequenced plasmid, pHK01 (human urine, Hong Kong, 2004). These pHK01-like plasmids were found to have spread to the major clones (ST68, ST405, and ST131) and multiple singleton isolates of all 4 phylogenetic groups. [Copyright &y& Elsevier]

Abstract: This study assessed the changes in serotype distribution and antibiotic resistance of Streptococcus pneumoniae isolates in children before and after introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in Hong Kong. Nasopharyngeal specimens were collected from 1978 and 2211 children (ages, 2 to 6 years) attending day care centers or kindergartens in period 1 (1999–2000) and period 2 (2009–2010), respectively. Carriage of PCV7 serotypes decreased from 12.8% to 8.6% (P < 0.01). The relative contribution of PCV7 serotypes 14 and 18C had decreased, whereas that for non-PCV7 serotypes 19A, 6A, 6C, 23A, and 15B had increased. In period 2, PCV7 penetration rate (at least 1 dose) for children aged 2, 3, 4, and 5 years was 43%, 35.7%, 26.7%, and 20.4%, respectively. In multivariate analysis, PCV7 use was the only independent variable associated with fewer PCV7 serotype carriages (odds ratio 0.5; P = 0.001). In period 2, high rates of dual penicillin/erythromycin nonsusceptibility were found in serotypes 6B (77.3%), 14 (100%), 19F (100%), 23F (78%), 19A (75%), 6A (87.8%), 6C (59.3%), and 23A (78.9%). [Copyright &y& Elsevier]

Abstract: This study analyzed 828 isolates causing invasive pneumococcal disease (IPD) before (1995–2001, n =265) and after (2007–2009, n =563) the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in Hong Kong. In children <5 years, serotype 14 had declined (36–15.7%, P <0.01) while 19A had increased (0–12.9%, P <0.01) in the before and after periods, respectively. In children aged <5 years, the proportion of PCV7 serotypes declined from 89.5% to 65.7% (72.8% if included cross protection against 6A) with time but that of PCV13 serotypes remained stable (91.4–93.2%). In elderly ≥65 years, 9V and 23F decreased from 3.8% to 0.3% (P =0.01) and from 18.9% to 7.4% (P <0.01), respectively while 7F increased significantly from 0% to 4.1% (P =0.04) over the same periods. Among isolates from aged <5 years, dual penicillin/erythromycin resistance increased from 44.1% to 64.2% (P =0.01). The types that often had dual penicillin/erythromycin resistance were 6B, 14, 19F, 23F, 6A and 19A. The emergence of serotype 19A was associated with expansion of sequence type 320. [Copyright &y& Elsevier]

Abstract: A study was conducted to determine the prevalence of the 2 newly described types, 6C and 6D, among pneumococcal isolates collected in Hong Kong before availability of the 7-valent pneumococcal conjugate vaccine. A total of 154 serogroup 6 isolates obtained from nasopharynx (n = 106), blood (n = 22), respiratory (n = 24), and cerebrospinal fluid (CSF) (n = 2) during 1995 to 2001 were analyzed by polymerase chain reaction typing. Five nasopharyngeal and 2 sputum isolates were found to belong to 6C and 6D, respectively. The isolates were genetically diverse, but one 6C and two 6D isolates exhibited some clonal relationship. Phylogenetic analysis of the wchA–wciNβ–wciO nucleotide sequences showed that the Hong Kong 6C/6D isolates had 2 allelic profiles, which were more closely related to 6C/6D isolates from Fijian and Korea than were those from Brazil and the United States. However, all of the wciP gene sequences for both Hong Kong and non-Hong Kong isolates clustered together: 6C isolates with the wciP-9 allele and 6D isolates with the wciP-5 allele. In conclusion, the prevalence of the 2 newly described serotypes was low before the era of the pneumococcal conjugate vaccine. Nonetheless, results from the molecular studies indicated that the evolution of the capsular genes have involved complex pathways. [ABSTRACT FROM AUTHOR]

Abstract: A prospective multicenter study was conducted to assess the epidemiology of antimicrobial resistance among uropathogens causing uncomplicated cystitis. Adult women with clinical diagnosis of uncomplicated cystitis were enrolled from 54 participating centers distributed all over Hong Kong during 2006 to 2008. A positive urine culture was found in 59.5% (352/592) patients. The patients had mean age of 44.9 years, and most (89.2%) were otherwise healthy. The most prevalent causative organism was Escherichia coli (77%), followed by other Enterobacteriaceae (14.2%), staphylococci (5.1%), and other Gram-positive bacteria (3.7%). The resistance rates of E. coli to co-trimoxazole and ciprofloxacin were 29.5% and 12.9%, respectively, and 14 isolates (5.2%) were confirmed as extended-spectrum β-lactamase (ESBL) producers. Of the ESBL producers, molecular studies showed CTX-M-14, CTX-M-24, or CTX-M-9. Nitrofurantoin and fosfomycin were active against >90% of the isolates, regardless of resistance phenotypes for other drugs. Pulsed-field gel electrophoresis of representative isolates showed that the antibiotic-resistant strains were genetically diverse. Patients with history of recent antibiotic use were significantly more likely to have infection by E. coli with co-trimoxazole resistance (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.4–5.7; P = 0.003) and ciprofloxacin resistance (OR, 2.5; 95% CI, 1.1–5.8; P = 0.03). Knowledge of the resistance data and risk factors could inform better use of antibiotics for empiric therapy for acute uncomplicated cystitis. [Copyright &y& Elsevier]

Abstract: This study assessed the susceptibility trend of methicillin-resistant Staphylococcus aureus (MRSA) in 5 Hong Kong hospitals from 1995 to 2005. Representative blood isolates were characterized to correlate the changes in resistance phenotypes with the clonal nature of MRSA. The prevalence of multisusceptible (MS) MRSA, defined by sensitivity to gentamicin, co-trimoxazole, and fusidic acid, was found to increase dramatically from <2% in 1995 to 1997 to 4.5% to 5.8% in 1998 to 1999 and remained at around 10% thereafter. Isolation of MS-MRSA was significantly associated with older age, convalescent care, and blood culture source. Molecular typing showed that the increasing isolation of MS-MRSA was associated with the spread of ST45/Staphylococcus cassette chromosome mec (SCCmec) IV or V with spa t1768, t1857, or t1081. Other features of the ST45 strains are as follows: agr4, capsular type 8, and Panton–Valentine leukocidin (PVL) negative. Two other epidemic clones, EMRSA-16 (ST36/SCCmec II) and CC398 (ST1277/SCCmec V), were detected as sporadic isolates for the first time in Hong Kong. [Copyright &y& Elsevier]

Abstract: This prospective study assessed the epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) among patients with purulent skin and soft tissue infections (SSTIs) in Hong Kong. Among 298 patients with SSTIs, 10.4% (13/125) of all S. aureus isolates and 5% (12/241) of all abscesses were attributed to pvl-positive CA-MRSA. Overall, 77% and 69.9% of CA-MRSA and methicillin-sensitive S. aureus (MSSA) were susceptible to erythromycin, 77% and 74.8% to clindamycin, 100% and 97.1% to minocycline, and 100% and 98.1% to rifampin, respectively. Filipino ethnicity was the only clinical and epidemiologic factor significantly associated with CA-MRSA infection (odds ratio, 14.8; 95% confidence interval, 3.3–70.0; P < 0.001). Pulsed-field gel electrophoresis analysis showed that 6 CA-MRSA isolates belonged to the ST30-HKU100 clone, 5 belonged to the ST59-HKU200 clone, and 1 was singleton. Features of HKU100 isolates include SCCmec type IV, agr3, spa t019, and pan-susceptibility to non–β-lactam antibiotics. In contrast, HKU200 isolates are characterized by having SCCmec type IV or V, agr4, spa t437, and variable non–β-lactam susceptibility profiles. The major CA-MRSA spa types were shared by a minority of the MSSA. [Copyright &y& Elsevier]

Abstract: This territory-wide study evaluated the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in residential care homes for elderly (RCHEs) in Hong Kong. MRSA colonization was assessed by taking swab culture from anterior nares and active skin lesions. Of 487 RCHEs surveyed, 80 MRSA strains were recovered from 1563 residents, giving a prevalence of 5.1%. Twenty-four isolates had SCCmec II, 2 had SCCmec III, 17 had SCCmec IV, 36 had SCCmec V, and 1 had a composite SCCmec type. Pulsed-field gel electrophoresis typing clustered 75 isolates into 7 clones (HKU10 to 50, HKU80, and HKU90). Two predominant types, HKU30 and HKU50, which together account for 75% of all MRSA strains, were found in 13 and 15 of the 18 geographic districts in Hong Kong, respectively. The main features for HKU50 strains were spa t1081/ST45-IV or V, capsular type 8, agrIV, and hla, seg, sei positive. On the other hand, HKU30 strains had spa t002/ST5-II, capsular type 5, agrII, and were hla, seg, sei positive. HKU30 strains were often multidrug resistant (MDR, involving ciprofloxacin, erythromycin, gentamicin, and tetracycline). In contrast, HKU50 strains exhibit both multidrug resistance (MDR) (involving ciprofloxacin, erythromycin, and tetracycline, but not gentamicin) and non-MDR patterns. [Copyright &y& Elsevier]

Abstract: This study evaluated the antimicrobial resistance profile of outpatient urinary Escherichia coli isolated from women obtained throughout Hong Kong during 2004–2005. Of 1067 single patient isolates analyzed, 60.1% were resistant to ampicillin, 34% were resistant to co-trimoxazole, and 22.1% were resistant to ciprofloxacin. Thirty-four (6.6%) of 519 isolates in 2004 and 55 (10%) of 548 isolates in 2005 were extended-spectrum β-lactamase (ESBL) producers with a CTX-M phenotype. Rates of non–β-lactam resistance and ESBL production were strongly influenced by patient age. The age-stratified rates for dual co-trimoxazole and ciprofloxacin resistance and for ESBL production were 10.9% and 7.6% in women aged 18–35 years, 13% and 6.9% in women aged 36–50 years, 20.4% and 8.8% in women aged 51–64 years, and 23.7% and 11.8% in women aged ≥65 years, respectively. Nitrofurantoin and fosfomycin remain active against >90% of the isolates, irrespective of the resistance phenotypes for other drugs. Our results documented the emergence of problematic resistance phenotypes among community urinary E. coli and highlight the need to explore strategies for their containment. [Copyright &y& Elsevier]

Abstract: In a population-based study, we use ICD-9-CM codes to estimate the hospitalization rates for pneumococcal disease among young children in Hong Kong, 2000–2005 and the preventable burden using several outcome indicators. For children aged ≤2 years, the average admission rates (per 100,000 person-years) were 23.7 for invasive pneumococcal disease (IPD), 1047.5 for clinical pneumonia and 213 for radiological pneumonia. For this group of children, the disease burden potentially preventable by vaccination, per 100,000 person-years, were estimated to be 19.3 (95% CI, 16.7–21.9) for IPD, 58.5 (95% CI, 57.3–59.6) for clinical pneumonia and 40.6 (95% CI, 59–82.2) for radiological pneumonia. [Copyright &y& Elsevier]

Abstract: This study evaluated the clinical and epidemiologic features of individuals with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Hong Kong from January 2004 through December 2005. Twenty-four episodes of skin and soft tissue infections and 1 episode of meningitis due to CA-MRSA were identified. CA-MRSA infections or carriage was found in 6 (13%) of 46 household contacts. A total of 29 isolates were analyzed by the Staphylococcus cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. In addition, polymerase chain reaction detection of the genes encoding Panton-Valentine leukocidin was also carried out. It was observed that 24 had SCCmec IV/IVA and 5 had SCCmec V, and 23 were pvl positive. PFGE analysis clustered all except 1 isolate into 3 pulsed-field types (PFTs), HKU100 through HKU300. The HKU100 isolates had genotype ST30-IV identical to the Southwest Pacific clone. The HKU200 isolates belonged to ST59-V and were multiresistant, including an ermB-mediated macrolide resistance trait, which is characteristic of the predominant CA-MRSA clone in Taiwan. The HKU300 isolates had unique features (ST8, Panton–Valentine leukocidin negative, and SCCmec IVA) typical of CA-MRSA in Japan. In conclusion, CA-MRSA has a propensity to spread within families. Our findings showed that CA-MRSA strains in Hong Kong have diverse genetic backgrounds. [Copyright &y& Elsevier]

A study was conducted to determine the vaccine coverage of prevalent carriage and invasive pneumococci from children aged less than 6 years in Hong Kong. A total of 383 nasopharyngeal carriage isolates and 88 invasive isolates from diverse sources were serotyped and their antimicrobial susceptibilities determined. The most common carriage serotypes were the same as the invasive isolates (6B, 14, 19F and 23F), although the rank order of specific serotypes was different. Serotypes in the 7-valent conjugate pneumococcal vaccine (4, 6B, 9V, 14, 18C, 19F and 23F) accounted for 89.7 and 66.1% of the invasive and carriage isolates, respectively. The same seven serotypes comprised 87.5% invasive isolates and 82.8% carriage isolates with resistance to penicillin, erythromycin and/or cefotaxime. [Copyright &y& Elsevier]

A case-control study was conducted in order to identify the risk factors associated with bloodstream infection caused by Escherichia coli producing extended-spectrum β-lactamase (ESBL) and to determine the outcomes of infected patients. Risk factors associated with ESBL production, according to univariate analysis, included a history of recent hospitalization [odds ratio (OR) 4.3, 95% confidence interval (CI) 2.1-8.9; p < 0.001], severe underlying diseases (OR 15, 95% CI 4.4-51.5; p < 0.001), prior exposure to urinary catheters (OR 8.3, 95% CI 3.2-21.7; p < 0.001) and nosocomial (OR 14.1, 95% CI 6.1-32.8; p < 0.001) or urinary (OR 3.6, 95% CI 1.7-7.4; p < 0.001) origin of the bacteria. Multivariate analysis revealed that severe underlying diseases (OR 31.2, 95% CI 6.7-144; p < 0.001) and nosocomial (OR 16.5, 95% CI 5.6-49; p < 0.001) and urinary origins (OR 7.8, 95% CI 2.6-23.8; p < 0.001) of the bacteria were independently associated with ESBL production in bacteremic E. coli. Crude mortality in case patients was more than twice as high as that in controls (p = 0.04). Production of ESBL increased the risk of inappropriate initial therapy (OR 95.6, 95% CI 27.4-334.2; p < 0.001). Treatment failed in 4/7 case patients treated with ceftazidime to which the isolate was susceptible in vitro. Our findings have implications for the choice of empirical therapy in nosocomial urinary tract infection. [ABSTRACT FROM AUTHOR]

The NG-Test CARBA 5 and Carbapenem-resistant K.N.I.V.O. Detection K-Set are lateral flow assays (LFAs) that rapidly detect five carbapenemases (KPC, NDM, IMP, VIM and OXA-48-like). We evaluated the effect of inoculum size on the performance of these two assays using 27 Enterobacterales isolates. Whole-genome sequencing (WGS) was used as the reference method. Using the NG-Test CARBA 5, eight Serratia spp. and six M. morganii isolates showed false-positive NDM results with a high inoculum. Using the Carbapenem-resistant K.N.I.V.O. Detection K-Set, eight M. morganii, four Serratia spp. and one K. pneumoniae isolates showed false-positive NDM and/or OXA-48-like bands at large inoculum sizes, while the other two M. morganii isolates demonstrated false-positive NDM and OXA-48-like results at all inoculum sizes. The false-positive bands varied in intensity. WGS confirmed that no carbapenemase gene was present. No protein sequence with a ≥50% identity to NDM or OXA-48-like enzymes was found. This study emphasizes the importance of assessing inoculum size in the diagnostic evaluation of LFAs. [ABSTRACT FROM AUTHOR]

The article discusses the clinical case of a one-year-old infant who was diagnosed with carbapenem-resistant Enterobacteriaceae (CRE). The patient was found to have New Delhi metallo-Β-lactamase (NDM)-1-producing Enterobacteriaceae. The authors concluded that the infant seemed to have acquired the blaNDM-1 gene during hospitalization in Hunan Province, India.

The article examines the prevalence of Escherichia coli producing extended-spectrum Β-lactamases (ESBL) in Hong Kong, China, based on the database of microbiology from a healthcare region from 2000 to 2010. The database was extracted and analyzed using linear regression in order to assess changes in the burden of Escherichia coli bacteremia. Variables such as hospital admissions and patient-days are also considered in this assessment.

The article discusses a study to determine the effect of implementing the new Clinical and Laboratory Standards Institute (CLSI) imipenem susceptibility breakpoints for Enterobacteriaceae in Hong Kong, China. It was noted that applying the new CLSI criteria drastically changed the susceptibility rates for some isolate groups. The reduction in imipenem susceptibility rate was dramatic for Proteus spp., Enterobacter spp., Providencia spp. and Morganella spp.

A letter to the editor is presented discussing a study on the vancomycin-resistant Enterococcus faecium among livestock animals in Hong Kong, China.

The article discusses a study which examined the presence of the O25-sequence type 131 clonal group among Escherichia coli isolates from a prospective cohort of female outpatients with cystitis in Hong Kong, China. 28.8% of patients had a history of urinary tract infection. Information on the phylogenetic group distribution of the isolates is provided. Results of the study showed that O25b-ST131 isolates were accounted for 45.7% of ciprofloxacin-resistant patients.

Presents a response by Florence H.Y. Yap, Pak-Leung Ho and Gavin M. Joynt to a letter to the editor about their article "Increase in Methicillin-Resistant Staphylococcus Aureus Acquisition Rate and Change in Pathogen Pattern Associated With an Outbreak of Acute Severe Respiratory Syndrome," in vol. 39, 2004 issue of the periodical "Clinical Infectious Diseases."

We describe the dissemination of Mycobacterium marinum infection from the right middle finger to the whole extremity and two legs, with the involvement of tendons and joints, in a patient who was treated with a steroid when Mycobacterium marinum infection was not suspected. The patient was successfully treated with a combined surgical and medical approach. [ABSTRACT FROM AUTHOR]

We report a case of a 62-y-old man who presented with fever, malaise and weight loss. He was diagnosed with pyrexia of unknown origin due to tuberculosis of the spleen. Combination anti-tuberculous therapy was administered and fever gradually subsided after 6 weeks. A 12-month course of anti-tuberculous treatment would appear to be appropriate for the treatment of most patients with splenic tuberculosis. [ABSTRACT FROM AUTHOR]

We describe the case of a patient with necrotizing fasciitis due to Vibrio alginolyticus in a patient with cirrhosis following an injury inflicted by a stingray. The patient was successfully treated with aggressive surgical debridement and a combination of ciprofloxacin and amoxicillin-clavulanate. Cases of invasive V. alginolyticus reported in the literature were reviewed. [ABSTRACT FROM AUTHOR]

The emergence and rapid spread of the mobile colistin resistance gene mcr-1 among bacterial species and hosts significantly challenge the efficacy of "last-line" antibiotic colistin. Previously, we reported silver nitrate and auranofin serve as colistin adjuvants for combating mcr-1-positive bacteria. Herein, we uncovered more gold-based drugs and nanoparticles, and found that they exhibited varying degree of synergisms with colistin on killing mcr-1-positive bacteria. However, pre-activation of the drugs by either glutathione or N-acetyl cysteine, thus releasing and accumulating gold ions, is perquisite for their abilities to substitute zinc cofactor from MCR-1 enzyme. X-ray crystallography and biophysical studies further supported the proposed mechanism. This study not only provides basis for combining gold-based drugs and colistin for combating mcr-1-positive bacterial infections, but also undoubtedly opens a new horizon for metabolism details of gold-based drugs in overcoming antimicrobial resistance. [ABSTRACT FROM AUTHOR]

While molnupiravir (MOV) and nirmatrelvir–ritonavir (NMV-r) were developed for treatment of mild to moderate COVID-19 infection, there has been a lack of data on the efficacy among unvaccinated adult patients with chronic respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD) and bronchiectasis. A territory-wide retrospective cohort study was conducted in Hong Kong to investigate the efficacy of MOV and NMV-r against severe outcomes of COVID-19 in unvaccinated adult patients with chronic respiratory diseases. A total of 3267 patients were included. NMV-r was effective in preventing respiratory failure (66.6%; 95% CI, 25.6–85.0%, p = 0.007), severe respiratory failure (77.0%; 95% CI, 6.9–94.3%, p = 0.039) with statistical significance, and COVID-19 related hospitalization (43.9%; 95% CI, −1.7–69.0%, p = 0.057) and in-hospital mortality (62.7%; 95% CI, −0.6–86.2, p = 0.051) with borderline statistical significance. MOV was effective in preventing COVID-19 related severe respiratory failure (48.2%; 95% CI 0.5–73.0, p = 0.048) and in-hospital mortality (58.3%; 95% CI 22.9–77.4, p = 0.005) but not hospitalization (p = 0.16) and respiratory failure (p = 0.10). In summary, both NMV-r and MOV are effective for reducing severe outcomes in unvaccinated COVID-19 patients with chronic respiratory diseases. [ABSTRACT FROM AUTHOR]

Focuses on the disseminated cryptococcosis with skin eruption in a patient with acute leukemia. Characterization of disseminated cryptococcosis; Difference on morphologic skin findings in HIV patients and non-HIV immunocompromised hosts; Observation of fungal pathogens in acute leukemia patients.

Objectives: Although the topic of antibiotic misuse is taught in medical schools, interns (fresh medical graduates) still encounter barriers to appropriate antibiotic prescription when they practice in hospitals under supervision. The impact of teaching in medical school, antibiotics stewardship program (ASP), and prescription guidelines was uncertain. This study explored the medical interns' views on antibiotic use and resistance, and their perceived enablers to appropriate antibiotic prescription. Methods: Two focus groups were conducted among medical interns with rotation experiences in different public hospitals of Hong Kong. The identified themes about attitudes to antibiotic resistance and enablers to appropriate antibiotic prescription were further examined by a questionnaire survey with 77 respondents. Results: The interns had lower preferences for tackling antibiotic resistance as they feared of delayed prescriptions. Guidelines provided by international evidence-based clinical resources and the interns' working hospitals were stronger enablers to appropriate antibiotic use than education materials from schools and the government. Qualitative findings revealed that the interns were aware of the existing ASP but doubted its effectiveness as it failed to get the prescribers' attention. They followed guidelines in their wards but perceived guidelines from local health authorities user-unfriendly. Knowledge from medical school was not very applicable. Varying prescribing practices between hospitals and the densely placed hospital beds made it difficult to prevent the spread of antimicrobial resistance. Conclusions: Minimizing delayed prescription is of a higher priority than tackling antibiotic resistance in medical interns' perspective. Interventions should target guidelines in hospitals and simplify the interface of local guidelines. [ABSTRACT FROM AUTHOR]

Background and Objective In Hong Kong, neonatal Bacillus Calmette- Guerin ( BCG) vaccination is practiced with 99% coverage. This study was to compare the performance of T- Spot. TB and tuberculin skin test ( TST) in predicting tuberculosis ( TB) among household contacts. Methods From 1 March 2006 to 31 July 2010, 1049 asymptomatic household contacts of smear-positive patients were simultaneously tested with T- Spot. TB and TST, and then followed for up to 5 years for development of TB. Attending clinicians and subjects were blinded to the results of T- Spot. TB. Results T- Spot. TB gave a significantly higher positive rate (32.7% vs 22.1%) and better association with exposure time than TST at the 15 mm cut-off. Agreement between T- Spot. TB and TST using cut-offs of 5, 10 and 15 mm were relatively poor (kappa 0.25-0.41) irrespective of presence or absence of BCG scar. Only T- Spot. TB positivity was negatively associated with BCG scar. Both T- Spot. TB (incidence rate ratio between test-positive and test-negative subjects, IRR: 8.2) and TST ( IRR: 4.1, 6.1 and 2.8, using cut-offs of 5 mm, 10 mm and 15 mm, respectively) helped to predict TB. Using a TST cut-off of 15 mm, 56% of future TB cases and 62.5% of bacteriologically confirmed cases were missed. Lowering the TST cut-off to 10 mm or 5 mm could achieve sensitivity comparable with that of T- Spot. TB, but at the expense of lower specificities, with more positive tests (thus requiring treatment) per case of TB predicted. Conclusions T- Spot. TB outperformed TST in predicting TB among household contacts in a high-income area with widespread BCG vaccination coverage. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluated the feasibility of using 2 multiplex allele-specific polymerase chain reaction (MAS-PCR) assays targeting 2 mutations (codon 315 of the katG gene and the 15th nucleotide preceding the mabA-inhA operon) to directly detect isoniazid (INH)-resistant Mycobacterium tuberculosis in cultured isolates and respiratory specimens. A total of 203 M. tuberculosis isolates and 487 respiratory specimens were investigated. The MAS-PCR assays successfully amplified all M. tuberculosis isolates and acid-fast bacilli smear-positive specimens while only 49.2% of the smear-negative specimens exhibited positive MAS-PCR results. The MAS-PCR assays identified 83.4% and 79.2% of the resistant strains in the culture isolates and respiratory specimens, respectively. All the inferred genotypes were in complete accordance with subsequent DNA sequence analyses. This study suggested the application of our improved MAS-PCR protocols to provide the rapid identification of INH-resistant M. tuberculosis directly in respiratory specimens. The technical simplicity, short turnaround time, and low cost of this molecular strategy should facilitate routine diagnostic services in developing areas with a high prevalence of drug-resistant tuberculosis. [ABSTRACT FROM AUTHOR]

Infections are among the leading causes of death for thalassemia major patients. The known predisposing factors of infection include prior splenectomy, iron overload and use of iron chelator such as deferoxamine (DFO). While encapsulated organisms frequently found in splenectomized patients were readily controlled by prophylactic vaccination and vigilant antibiotic treatment, ferrophilic organisms such as Yersinia and Klebsiella remain common pathogens in thalassemic patients.Yersiniainfections are more prevalent in temperate regions and Klebsiella infections are commonly found in tropical and subtropical areas. While the use of DFO further aggravates the risk ofYersiniainfection, oral chelators such as deferiprone (L1) do not enhance the growth of Yersinia in vitro or in vivo. We found that the growth of Klebsiella was marginally enhanced by DFO in vitro when compared to Yersinia. Such an unfavorable effect was not found in either L1 or deferasirox (DFRA) in vitro. The growth of Aeromonas was not affected by the presence of all three forms of chelators. Therefore, we suggest that factors other than DFO may account for the increased prevalence of Klebsiella and Aeromonas infection in Asian thalassemic patients. [ABSTRACT FROM AUTHOR]

An editorial is provided in which the authors discuss public health efforts to control the coronavirus disease 2019 (COVID-19) pandemic in Hong Kong, China, including through the mandatory quarantine of travelers, hand hygiene and the wearing of surgical masks. The role that hand hygiene and medical masks play in the prevention of COVID-19 virus transmission is discussed.