Antimicrobial Resistance Patterns of Staphylococcus Aureus Isolated at a General Hospital in Vietnam Between 2014 and 2021.

Purpose: Staphylococcus aureus is a commensal bacteria species that can cause various illnesses, from mild skin infections to severe diseases, such as bacteremia. The distribution and antimicrobial resistance (AMR) pattern of S. aureus varies by population, time, geographic location, and hospital wards. In this study, we elucidated the epidemiology and AMR patterns of S. aureus isolated from a general hospital in Vietnam. Methods: This was a cross-sectional study. Data on all S. aureus infections from 2014 to 2021 were collected from the Microbiology department of Military Hospital 103, Vietnam. Only the first isolation from each kind of specimen from a particular patient was analyzed using the Cochran-Armitage and chi-square tests. Results: A total of 1130 individuals were diagnosed as S. aureus infection. Among them, 1087 strains were tested for AMR features. Most patients with S. aureus infection were in the age group of 41-65 years (39.82%). S. aureus isolates were predominant in the surgery wards, and pus specimens were the most common source of isolates (50.62%). S. aureus was most resistant to azithromycin (82.28%), erythromycin (82.82%), and clindamycin (82.32%) and least resistant to teicoplanin (0.0%), tigecycline (0.16%), quinupristin-dalfopristin (0.43%), linezolid (0.62%), and vancomycin (2.92%). Methicillin-resistant S. aureus (MRSA) and multidrug-resistant (MDR) S. aureus were prevalent, accounting for 73.02% and 60.90% of the total strains respectively, and the strains isolated from the intensive care unit (ICU) had the highest percentage of multidrug resistance (77.78%) among the wards. Conclusion: These findings highlight the urgent need for continuous AMR surveillance and updated treatment guidelines, particularly considering high resistance in MRSA, MDR strains, and ICU isolates. Future research focusing on specific resistant populations and potential intervention strategies is crucial to combat this rising threat.

A simple method for detection of a novel coronavirus (SARS-CoV-2) using one-step RT-PCR followed by restriction fragment length polymorphism.

A novel coronavirus associated with acute respiratory disease (named SARS-CoV-2) is recently identified in Wuhan city, China, spread rapidly worldwide. Early identification of this novel coronavirus by molecular tools is critical for surveillance and control of the epidemic outbreak. We aimed to establish a simple method for the detection of SARS-CoV-2 in differentiating with SARS-CoV. Primers of our in-house reverse transcription polymerase chain reaction (RT-PCR) assays were designed to target conserved regions of the RdRP gene and E gene, selected restriction enzymes EcoRI, Tsp45I, and AluI to distinguish between SARS-CoV-2 and SARS-CoV. In this report, a 396-bp fragment of the RdRp gene and 345-bp fragment of the E gene were amplified by one-step RT-PCR. Enzyme Tsp45I cuts the RdRP-amplified product of SARS-CoV-2 generating three fragments of 45, 154, and 197 bp, but it did not cut the amplicon of SARS-CoV. In contrast, the amplified product of SARS-CoV was digested with EcoRI producing two fragments of 76 and 320 bp, whereas the amplicon of SARS-CoV-2 was undigested by Tsp45I help to distinguish clearly SARS-CoV-2 from SARS-CoV on gel electrophoresis. In addition, AluI cut the amplicon of the E gene of SARS-CoV-2 generating two fragments of 248 and 97 bp without cutting to SARS-CoV. The accuracy of the assay was confirmed by sequencing and phylogenetic analysis. When evaluated on clinical samples showed a high sensitivity of 95%, specificity of our assay was 100% and clinical performance for detection of SARS-CoV-2 in comparison with other reference assays. In conclusion, in the present study, we successfully developed a simple method for molecular detection of SARS-CoV-2 in differentiating with SARS-CoV.

Neopterin levels and Kyn/Trp ratios were significantly increased in dengue virus patients and subsequently decreased after recovery.

OBJECTIVES: During dengue fever, a pronounced gamma-interferon immune response produces neopterin and promotes tryptophan degradation by the enzyme indoleamine-2,3-dioxygenase 1 (IDO-1). Activated IDO-1 is indicated by an increased kynurenine to tryptophan ratio (Kyn/Trp) in patients. METHODS: Plasma levels of neopterin, kynurenine, and tryptophan were measured in 72 hospitalized dengue virus (DENV) patients and 100 healthy individuals. Plasma levels of neopterin, kynurenine, and tryptophan were also measured prospectively in a second cohort of 13 DENV patients; on the day of hospitalization, on day 2-3 at discharge, and 7-10 days after discharge. DENV RNA positivity was determined by qualitative and quantitative methodologies. RESULTS: DENV RNA-positive patients presented significantly higher levels of neopterin (mean 36.5nmol/l) and Kyn/Trp ratios (mean 102µmol/mmol) compared to DENV RNA-negative individuals. A significant correlation between neopterin levels and Kyn/Trp ratios was observed in both DENV RNA-positive (Spearman's rho=0.37, p< 0.01) and DENV RNA-negative (Spearman's rho=0.89, p<0.001) patients. Kyn/Trp ratios were negatively correlated with platelet counts (Spearman's rho=-0.43, p<0.01) and positively correlated with liver enzymes: AST (Spearman's rho=0.68, p<0.01) and ALT (Spearman's rho=0.51, p<0.05). In addition, the follow-up data presented a significant decrease in neopterin levels and Kyn/Trp ratios within 10 days after hospital entry. CONCLUSIONS: Neopterin levels and Kyn/Trp ratios were significantly increased in DENV patients and subsequently decreased after recovery.

Molecular analysis of pyrazinamide resistance in Mycobacterium tuberculosis in Vietnam highlights the high rate of pyrazinamide resistance-associated mutations in clinical isolates.

Pyrazinamide (PZA) is a key antibiotic in current anti-tuberculosis regimens. Although the WHO has stressed the urgent need to obtain data on PZA resistance, in high tuberculosis burden countries, little is known about the level of PZA resistance, the genetic basis of such resistance or its link with Mycobacterium tuberculosis families. In this context, this study assessed PZA resistance through the molecular analysis of 260 Vietnamese M. tuberculosis isolates. First-line drug susceptibility testing, pncA gene sequencing, spoligotyping and mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing were performed. Overall, the pncA mutation frequency was 38.1% (99 out of 260 isolates) but was higher than 72% (89 out of 123 isolates) in multidrug and quadruple-drug resistant isolates. Many different pncA mutations (71 types) were detected, of which 55 have been previously described and 50 were linked to PZA resistance. Among the 16 novel mutations, 14 are likely to be linked to PZA resistance because of their mutation types or codon positions. Genotype analysis revealed that PZA resistance can emerge in any M. tuberculosis cluster or family, although the mutation frequency was the highest in Beijing family isolates (47.7%, 62 out of 130 isolates). These data highlight the high rate of PZA resistance-associated mutations in M. tuberculosis clinical isolates in Vietnam and bring into question the use of PZA for current and future treatment regimens of multidrug-resistant tuberculosis without PZA resistance testing.

Enterococcus and Streptococcus spp. associated with chronic and self-medicated urinary tract infections in Vietnam.

BACKGROUND: Urinary tract infections (UTI) are one of the most common infections among women worldwide. E. coli often causes more than 75% of acute uncomplicated UTI, however, little is known about how recurrent UTIs and indiscriminate use of antimicrobials affect the aetiology of UTIs. This study aimed to establish the aetiology of UTI in a population of recurrent and self-medicated patients referred from pharmacies to a hospital in Hanoi, Vietnam and to describe genotypes and antimicrobial susceptibility of the associated bacterial pathogens. The aetiology of bacterial pathogens associated with UTI (defined as ≥ 104 CFU/ml urine) was established by phenotypic and molecular methods. Enterococcus faecalis isolates were typed by Multi Locus Sequence Typing (MLST), Pulsed-Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility testing. METHODS: Urine samples from 276 patients suffering symptoms of urinary tract infection were collected and cultured on Flexicult agar® allowing for detection of the most common urine pathogens. Patients were interviewed about underlying diseases, duration of symptoms, earlier episodes of UTI, number of episodes diagnosed by doctors and treatment in relation to UTI. All tentative E. faecalis and E. faecium isolates were identified to species level by PCR, 16S rRNA and partial sequencing of the groEL gene. E. faecalis isolates were further characterized by Multi Locus Sequence Typing and antimicrobial susceptibility testing. RESULTS: Mean age of 49 patients was 48 yrs (range was 11-86 yrs) and included 94% women. On average, patients reported to have suffered from UTI for 348 days (range 3 days-10 years, and experienced 2.7 UTIs during the previous year). Cephalosporins were reported the second drug of choice in treatment of UTI at the hospital. E. faecalis (55.1%), E. coli (12.2%) and Streptococcus gallolyticus subsp. pasteurianus (8.2%) were main bacterial pathogens. MIC testing of E. faecalis showed susceptibility to ampicillin, penicillin and vancomycin, but high-level resistance against gentamicin (48.1%). MLST revealed 12 Sequence Types (ST) of which ST 16 made up 44.5% and showed closely related PFGE types. CONCLUSION: The different aetiology of UTI compared with reports elsewhere, where E. coli dominates, may be a result of chronic and recurrent UTIs together with indiscriminate use of antimicrobials. The similar genotypes shown by epidemiologically unrelated ST 16 isolates in Vietnam and elsewhere, suggest that E. faecalis ST 16 might represent a globally distributed clone. Treatment of UTI with cephalosporins may select for E. faecalis as it is intrinsic resistant and further studies are needed to establish the source(s) and role of E. faecalis ST 16 in acute UTI.

Enterococcus faecalis clones in poultry and in humans with urinary tract infections, Vietnam.

Enterococcus spp. as pathogens have increased, but the sources of infection often remain unclear. To investigate whether poultry might be a reservoir for E. faecalis-associated urinary tract infections (UTIs) in humans, we characterized E. faecalis isolates from patients in Vietnam with UTIs during January 2008-January 2010 and poultry living in close contact with them by multilocus sequence typing (MLST), pulsed-field gel electrophoresis, analysis of antimicrobial drug susceptibility patterns, and sequencing of virulence genes. In 7 (23%) of 31 UTI cases, we detected identical MLST, indistinguishable or closely related pulsed-field gel electrophoresis patterns, and similar antimicrobial drug susceptibility patterns. Isolates from urine and poultry showed identical virulence gene profiles, except for 1 variation, and individual genes showed identical sequences. The homology of isolates from urine and poultry further indicates the zoonotic potential and global spread of E. faecalis sequence type 16, which recently was reported in humans with endocarditis and in pigs in Denmark.

Molecular characteristics of rifampin- and isoniazid-resistant mycobacterium tuberculosis strains isolated in Vietnam.

Molecular characterization of the drug resistance of Mycobacterium tuberculosis strains with different origins can generate information that is useful for developing molecular methods. These methods are widely applicable for rapid detection of drug resistance. A total of 166 rifampin (RIF)- and/or isoniazid (INH)-resistant strains of M. tuberculosis have been isolated from different parts of Vietnam; they were screened for mutations associated with resistance to these drugs by sequence analysis investigating genetic mutations associated with RIF and INH resistance. Seventeen different mutations were identified in 74 RIF-resistant strains, 56 of which (approximately 76%) had mutations in the so-called 81-bp "hot-spot" region of the rpoB gene. The most common point mutations were in codons 531 (37.8%), 526 (23%), and 516 (9.46%) of the rpoB gene. Mutations were not found in three strains (4.05%). In the case of INH resistance, five different mutations in the katG genes of 82 resistant strains were detected, among which the nucleotide substitution at codon 315 (76.83%) is the most common mutation. This study provided the first molecular characterization of INH and RIF resistance of M. tuberculosis strains from Vietnam, and detection of the katG and rpoB mutations of the INH and RIF-resistant strains should be useful for rapid detection of the INH- and RIF-resistant strains by molecular tests.

Assessment of the status of resources for essential trauma care in Hanoi and Khanh Hoa, Vietnam.

INTRODUCTION: The World Health Organization and the International Association for Trauma Surgery and Intensive Care have published the Guidelines for Essential Trauma Care. This provides recommendations for the human and physical resources needed to provide an adequate, essential level of trauma care services in countries at all economic levels worldwide. We sought to use this set of recommendations as a basis to assess the trauma care capabilities in two locations in Vietnam and thus to identify affordable and sustainable methods to strengthen trauma care nationwide. METHODS: A needs assessment tool was created that incorporated the recommendations of the Guidelines. This was used to conduct in-depth, onsite evaluations of 11 health care facilities in Hanoi and Khanh Hoa Province, including commune health stations, district hospitals, provincial hospitals, and a central hospital. RESULTS: Resources for trauma care were mostly adequate at provincial and central hospitals. There were several deficiencies at the district hospitals and especially at commune health stations. These included low level of trauma related training and shortages of supplies and equipment. In many cases these shortages were of low-cost items. However, in general, capabilities had improved compared with prior evaluations. CONCLUSIONS: This study has identified several low-cost ways in which to strengthen trauma care in Vietnam. These include greater use of continuing education courses for trauma care and more attention to trauma related curriculum in schools of medicine and nursing. These also include defining and assuring the availability of a core set of essential trauma related equipment and supplies. A policy recommendation that follows from the above findings is the need for programs to strengthen the organization and planning for trauma care.