Abstract: BACKGROUND: Moraxella catarrhalis, occasionally, plays the essential role in nosocomial respiratory infection (NRI). Few studies have reported the route by which this organism spreads in a nosocomial infection outbreak. We identified characteristics of the strains isolated from NRI and attempted to reveal the potential nosocomial transmission routes. METHODS: A follow-up study has been performed in a Japanese community hospital between July 2002 and January 2003. M. catarrhalis clinical isolates were identified and beta-lactamase production test as well as the minimal inhibitory concentrations (MICs) have been examined. Pulsed-field gel electrophoresis (PFGE) and the multi locus sequence typing method (MLST) have been introduced as the effective "fingerprinting" methods. RESULTS: A total of 29 strains were isolated from 17 participants; 7 independent DNA fragment patterns were detected by PFGE. Pattern B (defined in this study) was dominant, and was detected both in strains from a health care worker (HCW) and inpatients. In the 9 selected strains analyzed by MLST, 7 unique MLST types were identified, which showed the congruence with the results of PFGE results. CONCLUSION: Epidemiological analysis proved the transmission route from patient to patient, and suggested that more studies should be focused on identifying the possible transmission route between HCWs and inpatients.

Abstract: OBJECTIVE: Bacterial biofilms cause serious problems, such as antibiotic resistance and medical device-related infections. Recent reports indicate that Bacillus species potentially form biofilms and cause nosocomial bacteremia via catheter infection. Our objective was to investigate the relationship between nosocomial bacteremia caused by Bacillus species and biofilm formations. METHODS: Between 2001 and 2006, Bacillus cereus and Bacillus thuringiensis were isolated from blood samples of 21 patients with nosocomial bacteremia in two hospitals. The patients had underlying diseases such as cerebrovascular damage, malignant disease, or chronic obstructive lung disease and had high fever at the onset of bacteremia. After investigation, B. cereus and B. thuringiensis were isolated from patient's catheter tip, gauze, and hospital environment. Pulsed-field gel electrophoresis (PFGE) on 32 B. cereus and 7 B. thuringiensis isolates, microtiter biofilm assay and scanning electron microscopy (SEM) on 22 B. cereus isolates from patient's blood were performed. RESULTS: Molecular analysis by PFGE showed that 32 B. cereus strains had 21 patterns and 7 B. thuringiensis strains had 3 patterns. The PFGE patterns of B. thuringiensis and B. cereus in blood samples from 2 patients blood were similar to those from the same patient's catheter tip. The PFGE pattern of B. cereus from a hospital environment was similar to that from 2 patients' blood samples, and the PFGE pattern of B. thuringiensis from 2 hospital environments was similar to that from 2 patients' blood. The biofilm formations by 22 B. cereus isolates from patients' blood were confirmed by microtiter biofilm assay and SEM even at 24 hours. CONCLUSION: Our data indicate that various types of Bacillus species exist in hospital environments and the biofilm-forming strains potentially cause nosocomial bacteremia by catheter infection.

Abstract: Our study was undertaken to investigate the characteristics of Haemophilus influenzae in young children with acute lower respiratory tract infections in Nha Trang, Vietnam. The study population consisted of 116 children less than 5 years of age admitted to Khanh Hoa General Hospital due to acute lower respiratory tract infections between July 2004 and April 2005. Organisms could be detected from nasopharyngeal swabs (NP) in 72 (62.1%) of the 116 children. Haemophilus influenzae was the most common organism, and 39 strains were isolated from 39 children aged 2 to 60 months (mean age, 16 months). We examined 37 of these 39 H. influenzae strains. The serotypes of the 37 isolates were all nontypeable, and 22 strains (59.5%) were beta-lactamase producing. Polymerase chain reaction (PCR) analysis to identify resistance genes revealed that 17 strains had the TEM-1-type beta-lactamase gene alone, 6 strains had the ftsI gene with the same substitution as that in g low-beta-lactamase-negative ampicillin-resistant (g low-BLNAR) strains, and 6 strains had both the TEM-1-type beta-lactamase gene and the ftsI gene with the same substitution as that in g beta-lactamase-producing amoxicillin clavulanic acid-resistant (g BLPACR I) strains, although no BLNAR strains were found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 6 g low-BLNAR strains had five PFGE patterns and the 6 g BLPACR I strains had four PFGE patterns. Our results indicate that BLNAR strains are still not prevalent, but that g low-BLNAR and g BLPACR I strains are potentially spreading in Nha Trang, Vietnam.

Abstract: The minimum inhibitory concentration (MIC) of five antibiotics and the presence of resistance genes was determined in 163 Haemophilus influenzae isolates collected over 13 years (1987-2000) in four two-yearly sampling periods from patients with respiratory tract infections. The prevalence of beta-lactamase-negative ampicillin-susceptible strains was approximately 80% over the sampling period although fewer strains (65.9%) were recovered in the period 1995-1997. TEM-1 type beta-lactamase-producing strains were less frequent starting at 15.6% and declining to 2.2% in the final sampling period. Low-beta-lactamase-negative ampicillin-resistant (BLNAR) strains were uncommon in 1987-1989 (2.2%), peaked to 19.5% in 1995-1997, but fell back to 11.1% by 2000. Fully BLNAR strains were not detected until the last sampling period (6.7%). The MICs of ampicillin, levofloxacin, cefditoren and ceftriaxone remained stable but there was an eight-fold increase in the MIC of cefdinir over the sampling period. Pulsed-field gel electrophoresis of DNA digests showed that three representative BLNAR strains were genetically distinct and 11 DNA profiles were identified among 17 low-BLNAR strains. These data suggest that the number of genetically altered BLNAR and low-BLNAR strains are increasing in Japan.

Abstract: OBJECTIVE: The objective of this prospective study was to investigate the status of acute respiratory tract infections caused by Haemophilus influenzae and Streptococcus pneumoniae in tsunami disaster evacuation camps. METHODS: Nasopharyngeal swabs (NP) of 324 internally displaced persons (IDP) in 3 different tsunami disaster evacuation camps of Sri Lanka were collected between March 18th and 20th, 2005, and analyzed for MIC, beta-lactamase production, serotypes, PCR and pulsed-field gel electrophoresis (PFGE). RESULTS: Many IDP had respiratory symptoms and the prevalence of cough and/or sputum was 84%, 70.5% and 64.7% in the three camps. Twenty-one H. influenzae from 20 IDP and 25 S. pneumoniae from 22 IDP were isolated from the NP. All H. influenzae isolates were nontypeable, and 5 were beta-lactamase producing. Seventeen pneumococci were susceptible, 5 showed intermediate resistance and 3 were fully resistant to penicillin G. Molecular analysis showed the 21 H. influenzae strains had 13 PFGE patterns and 25 pneumococci had 16 PFGE patterns. All 4 different PFGE patterns of H. influenzae strains were detected in a few IDP in camps 1 and 3, and 5 different PFGE patterns of serotype 3, 22A, 9A, 10A and 11A pneumococci were detected in a few IDP in camps 1 and 3. CONCLUSION: Our data indicate acute respiratory tract infections caused by various types of H. influenzae and S. pneumoniae appear to have been prevalent, some of which were potentially transmitted from person to person in tsunami disaster evacuation camps.

Abstract: A clinical study was designed to study Streptococcus pneumoniae isolates recovered from a community hospital in Japan from April 2001 to November 2002. A total of 73 isolates were defined as derived from inpatient, outpatient, and hospital staff groups. The MIC results showed that 20 strains (27.4%) were susceptible to penicillin G, 39 strains (53.4%) had intermediate resistance, and 14 strains (19.2%) had full resistance. Low susceptibility to macrolides was also detected: 32.9%, 32.9%, and 34.2% of all strains were resistant to erythromycin, clarithromycin, and azithromycin, respectively. Thirty strains (41%) were resistant to at least two different kinds of antibiotics. Nineteen disparate serotypes were detected besides two nontypeable strains, and the predominant serotypes were 19F and 23F. Pulsed-field gel electrophoresis (PFGE) pattern A was dominant in the serotype 19F group; this pattern was similar to that of the international clone Taiwan 19F. A total of 10 different patterns were detected in the 23F group and were distinguishable from those of the international clones Spain 23F and Taiwan 23F. Pattern b strains were identified in the same ward, and pattern d strains were found both in patients with nosocomial pneumococcal infections (NPI) and in outpatients. In conclusion, drug-resistant S. pneumoniae was spreading rapidly, especially isolates of the serotype 19F and 23F groups. PFGE data revealed interpatient transmission and suggested that there might be some association between NPI patient strains and outpatient strains.

Abstract: A nationwide study was undertaken to determine the susceptibility to penicillin and serotypes of Streptococcus pneumoniae in Japan. S. pneumoniae was isolated from 114 adult patients with community-acquired pneumonia over 22 months at 20 hospitals and medical centres in different regions in Japan. All but five isolates were from sputum. Forty-eight isolates (42.1%) were susceptible, 40 (35.1%) showed intermediate resistance (MIC, 0.12-1.0 microg/ml) and 26 (22.8%) were resistant (MIC, >or=2.0 microg/ml) to penicillin G. All isolates were susceptible to ceftriaxone (breakpoint 1 microg/ml), imipenem (4 microg/ml) and vancomycin (4 microg/ml). Most were resistant to erythromycin, clarithromycin and azithromycin; only two were resistant to levofloxacin. Differences were found in the distribution of serotypes among isolates showing susceptibility to penicillin (predominant types 3, 6B, and 19F), intermediate resistance (6B, 14, 19F, and 23F) and full resistance (19F and 23F). PFGE typing showed that 14 of the 25 strains of serotype 19F had a single DNA profile, pattern A, a pattern closely similar to that of the Taiwan multidrug-resistant 19F clone. Twelve pattern A strains were not susceptible to penicillin but carried the macrolide resistance gene mef(A). The DNA profiles of the 15 strains of 23F were also heterogeneous but six were highly similar (pattern b) yet distinct from the Spanish multidrug-resistant 23F clone although possibly related to the Taiwan multidrug-resistant 23F clone. The pattern b strains were not susceptible to penicillin and also harboured either mef(A) or erm(B). Our results indicate that multidrug-resistant pneumococci are spreading rapidly in Japan. Efforts to prevent the spread of the pandemic multidrug-resistant serotypes should be intensified.

Abstract: SARS (Severe Acute Respiratory Syndrome) is a newly emerging infectious disease which spread over 32 countries and areas, infected more than 8,000 people and causing more than 900 deaths from November 2002 to August 2003. More than 90% of the SARS cases and death were reported from China. Nevertheless, we still know little about this disease, particularly in etiology. SARS, as an emergency of Public Health System (PHS), alarmed health workers throughout the world proving there is still the potential for an epidemic of an emerging infection both in developed and developing areas. Many reports indicated that the insufficiency of the PHS of China was one of the critical factors contributing to the outbreak of SARS. In this study, we attempt to demonstrate some of the categories of PHS that contributed to the SARS epidemic. Two of the categories studied were the living environment and health resources. In the living environment area, the population and population density were examined. Health resources include the medical facilities, health workers, and per capita public health expenditures. An understanding of these areas is important to prevent future epidemic.

Abstract: The possible intrafamiliar transmission of Moraxella catarrhalis was evaluated in 3 pairs between children and their parents, and 8 pairs between siblings from 11 families. Of the 22 isolates, all were found producing beta-lactamase. Molecular typing by pulsed-field gel electrophoresis (PFGE) with Not I and Spe I showed that the PFGE patterns in 2 of 3 pairs between children and their parents, and 4 of 8 pairs between siblings were indistinguishable and those of the remaining pairs were different. These data indicate a possible high rate of intrafamiliar transmission of M. catarrhalis.

Abstract: Two decades have already passed since the first HIV/AIDS case was described in 1981. Cumulatively, over 20 million people have unfortunately lost their lives, and more than 40 million people are now living with HIV, and most of them are from developing countries. China, as the biggest developing country, has an impact on the epidemic of HIV/AIDS. From the first case of AIDS diagnosed in Mainland China in 1985, the epidemic has spread at an alarming rate. The feature of HIV/AIDS spread in Mainland China concerns its geographical characteristics that can be described as occurring in three phases. According to data from World Health Organization (WHO), it was estimated that about 840,000 people are living with HIV/AIDS in China, and 80,000 of them have already developed AIDS. WHO warned that, if there were no effective preventive measures adopted, that the number of HIV/AIDS infected cases would reach 10 million in China by 2010.In this study, we described the current situation of the epidemic of HIV/AIDS, as well as an historic review. The development of policy-making and the control measures are also highlighted. The experience from China described in this study would hopefully be for more public awareness of this crisis that is threatening all the citizenry of China.