A Retrospective Study about the Impact of Switching from Nested PCR to Multiplex Real-Time PCR on the Distribution of the Human Papillomavirus (HPV) Genotypes.

BACKGROUND AND OBJECTIVES: Human papillomavirus (HPV) is the most prevalent etiological agent of viral sexually-transmitted infection. This study retrospectively evaluated the impact of a switch to a real-time PCR assay in the HPV prevalence and genotypes distribution by a quasi-experimental before-and-after approach. MATERIALS AND METHODS: In total, 1742 samples collected from 1433 patients were analyzed at the UOC Microbiology and Virology of Policlinico of Bari, Italy. HPV DNA detection was performed using initially nested PCR and subsequently multiplex real-time PCR assay. RESULTS: Statistically significant difference in HPV overall prevalence after the introduction of the real-time assay was not detected (48.97% vs. 50.62%). According to different extraction-DNA amplification methods, differences were observed in the prevalence rates of HPV-45, 68, 40, 42, and 43. The lowest prevalence for HPV-45 was observed in the Magna Pure-Real Time PCR group, while HPV-68, 40, 42, and 43 were less observed in the Qiagen-Real Time PCR group. After, a multivariate logistic regression, an increase in the prevalence of HPV-42 (aOR: 4.08, 95% CI: 1.71-9.73) was associated with the multiplex real-time PCR assay. CONCLUSIONS: Although this study is a not a direct comparison between two diagnostic methods because it has a sequential structure, it serves to verify the impact of a new molecular assay on HPV distribution. Moreover, the stability of HPV prevalence over time suggests that the population composition and the behavioral variables did not likely change during the observation period. Our study proposes that the introduction of a molecular test for HPV detection may be related to changes of HPV genotypes distribution.

Epidemiological evaluation of human papillomavirus genotypes and their associations in multiple infections.

The aim of this study was to determine the frequency of multiple type human papillomavirus (HPV) infections, and whether any types are involved in multiple HPV-type infections (mHPV) more or less frequently than expected. From January 2012 to February 2018, 2848 cervico-vaginal swabs were analysed in the UOC Microbiology and Virology of Policlinico of Bari, Italy. HPV DNA detection was performed using initially nested-polymerase chain reaction (PCR) and subsequently multiplex real-time PCR assay. 1357/2848 samples (47.65%) were HPV DNA positive and 694/1357 (51.14%) showed mHPVs. The median number of mHPVs was 2 (interquartile range: 2-3). HPV-types more frequently detected were 42 (9.97%), 16 (8.92%), 53 (7.23%) and 31 (7.16%). Each detected HPV-type was involved in mHPVs in more than 50% of cases. Statistical analysis showed significant associations for all HPV-types except for 33, 43, 51, 58 and 82 HPV-types. The major number of significant pairwise associations were detected for the types 42 and 70. Only positive associations were detected. Further data are necessary to evaluate the clinical impact of the single combinations.

Trends in Klebsiella pneumoniae strains isolated from the bloodstream in a teaching hospital in southern Italy.

Klebsiella pneumoniae is a common nosocomial pathogen involved in many infectious diseases such as bacteraemia, urinary and respiratory tract infections. It is responsible for the rise in morbidity and mortality rates since most clinical isolates exhibit resistance to several antibiotics. Moreover, the epidemiology of these nosocomial infections is variable across countries and regions. From January 2015 to December 2017 we retrospectively analysed the bloodstream infections caused by K. pneumoniae strains in hospitalised patients with the aim of studying the temporal trends of wild type (WT), multi-drug resistant (MDR), extended drug resistant (XDR), pan-drug resistant (PDR) and carbapenem-resistant (CR) strains. In all, 439 K. pneumoniae isolates from 356 patients were collected from all units of the Policlinico of Bari. The majority of clinical isolates were collected from the intensive care unit (125, 28.47%), haematology (34, 7.74%), rehabilitation (27, 6.15%) and cardiac surgery wards (25, 5.69%). Moreover, the majority of the isolates were classified as CR (325, 74.03%, 95%CI: 69.61-78.19) and XDR (255, 58.09%, 95%CI: 53.31-62.72). Annual prevalence rates and monthly counts were analysed using the Chi Squared test for trends and the Poisson regression with multiple p-value correction according to Benjamini and Hochberg's procedure. The annual relative frequencies of the XDR and CR K. pneumoniae isolates decreased significantly from 63.37% to 48.44% and from 78.48% to 63.28% respectively, while WT K. pneumoniae significantly increased from 13.95% to 23.44%. Poisson regression analysis confirmed the presence of a decreasing monthly trend for the XDR and CR K. pneumoniae count series. In order to control the spread of antibiotic resistance, more inclusive surveillance data will be needed to either confirm these results or improve antibiotic stewardship measures.

Prevalence of Clostridium difficile and ribotype 027 infection in patients with nosocomial diarrhoea in Southern Italy.

Clostridium difficile is an emerging cause of healthcare-associated infections. The increasing frequency and severity is attributed to highly virulent ribotypes such as 027. The aim of this study was to retrospectively analyze the prevalence of CDI and ribotype 027 in 481 clinical samples collected from hospitalized patients and sent to the laboratory of molecular biology, UOC Microbiology and Virology, Azienda Ospedaliera-Universitaria, Policlinico of Bari, Italy. Toxins A+B and DNA C. difficile detections were performed using immunochromatographic test and a multiplex real-time PCR assay, respectively. Overall, 37/366 (10.11%) patients were positive at the immunochromatographic assay. This result was confirmed in 31 (8.47%) samples from 31 different patients by molecular assay. Logist regression confirmed age >50 years (adjusted odds ratio [aOR]: 4.29, 95%CI:1.44-18.50) and hospitalization in the Infectious Diseases (aOR: 3.77, 95%CI: 1.34-9.85) ward were risk factors for CDI. The associated 027 ribotype deletion D117tcd was detected in seven (22.58%) of 31 positive patients. Exploratory analysis of monthly prevalence of 027 ribotype suggested a slight increase after August 2015. Our results show that a monitoring program is needed to either better assess the diffusion of CDI and ribotype 027 or also to establish the risk factors associated with the transmission in our healthcare facilities.

Prevalence, genotype distribution and temporal dynamics of human papillomavirus infection in a population in southern Italy.

Human papillomavirus (HPV) is considered the most important risk factor for the development of ano-genital region cancer in both women and men. Whereas low-risk genotypes are responsible for cutaneous and genital lesions, high-risk genotypes are associated with ano-genital cancer. The aim of this study was to retrospectively analyse the prevalence, genotype distribution and temporal dynamics of HPV infection in 2312 specimens from 2312 subjects (2149 women and 163 men) who attended the laboratory of molecular biology, UOC Microbiology and Virology, Azienda Ospedaliera-Universitaria, Policlinico of Bari, Italy. HPV DNA detection and genotyping was performed using a multiplex real-time PCR assay. In all, 1123/2312 subjects (48.57%) resulted positive for HPV DNA. In particular, HPV DNA was detected in (1056) 49.14% of females and (67) 41.10% of males. HPV co-infections were detected in 565 (24.44%) patients. High-risk and low-risk HPV genotypes were detected in 887 (38.37%) and 600 (25.95%) patients, respectively. The most prevalent HPV genotypes were HPV-42 (10.29%), HPV-16 (8.56%), HPV-31 (7.40%) and HPV-53 (7.14%). Statistically significant differences between female and male patients were not detected. Moreover, HPV prevalence remained constant in time while HPV-16, but not HPV-6, 11 and 18, showed a decreasing trend from 2013 (11.24%) to 2016 (6.67%). Other HPV genotypes showed some complex and different patterns. Our data showed an unusually high frequency of HPV-42 and a high prevalence of HPV infection in the patients analysed. Although evidence of a decreasing trend of HPV-16 could be a consequence of anti-HPV vaccination, corroboration from further studies will be needed. Moreover, the small number of studied males and the similarity to females in terms of HPV prevalence suggest that more active HPV screening and anti-HPV vaccination in the male population should be considered important tools to eliminate HPV sexual transmission.

Simultaneous detection and identification of STI pathogens by multiplex Real-Time PCR in genital tract specimens in a selected area of Apulia, a region of Southern Italy.

PURPOSE: Genital tract infections are globally a major cause of morbidity in sexually active individuals. The aim of this study was to investigate the prevalence and associations of co-infections of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma hominis (MH), Mycoplasma genitalium, Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) in specimens collected from female (SF) and male (SM) patients. METHODS: 1575 samples from 1575 individuals from the geographical area around Bari, Apulia region in Southern Italy, were collected and analyzed by a multiplex Real-Time PCR (mRT-PCR) (AnyplexTM II STI-7, Seegene, Inc., Seoul, Korea) assay. RESULTS: 455/1575 (28.89%) samples resulted positive for at least one of the targets named above. Statistically significant differences in prevalence of the pathogens between SF and SM were not detected except for UP (24.92% in SF vs 8.91% in SM). Prevalence of co-infections was 6.84 and 3.96% in SF and SM, respectively. Moreover, MH presence in SF, but not in SM, was associated with UU and UP. CONCLUSIONS: Our data suggest different patterns of infections between females and male and the importance of an increased vigilance of sexually transmitted pathogens to reduce the burden on general population and the sequelae or the complications on reproductive organs.