Simkania negevensis has been implicated in respiratory diseases. This study aimed to unveil the aetiological role of this bacterium in community-acquired pneumonia (CAP) and bronchitis in Jordanian adults. Nasopharyngeal samples were collected from 98 CAP or bronchitis patients and 96 control individuals, and tested for Simkania nucleic acids using a PCR assay. The overall prevalence of the bacterial DNA in patients was markedly high and reached 57.1 %. Intriguingly, Simkania DNA was detected in 62.5 % of the nasopharyngeal swabs collected from apparently healthy controls (P>0.05). The DNA positivity in the bronchitis and CAP subgroups was 57.7 and 56.9 %, respectively, percentages that are approximately comparable to the DNA positivity assessed for the entire patient population. Simkania is most likely not a causative agent of CAP or bronchitis, despite its remarkable high prevalence. This organism, in the nasopharynx, is potentially harmless to the host and may coexist in a commensal relationship.

Introduction: This study investigated the role of Chlamydia pneumoniae in the etiology of community-acquired pneumonia (CAP) in Jordanian adults. Methodology: Eighty hospitalized CAP patients and 110 healthy adults were enrolled. Overall prevalences of C. pneumoniae IgG antibodies in sera and the rate of acute infection were estimated, using the microimmunofluorescence method (MIF), at titers of 1:16 and 1:512, respectively. Moreover, a nested polymerase chain reaction (PCR) was used to detect C. pneumoniae DNA in nasopharyngeal and blood Buffy coat samples. Results: Overall chlamydial IgG prevalence was higher in CAP cases than controls (70% versus 61.8%). Similarly, higher rate of acute infection was found in patients than in controls (16.3% versus 5.5%). By focusing on subjects testing positive at 1:16, acute infection was detectable in 23.2% of CAP cases, compared with 8.8% of seropositive controls. Chlamydial DNA was confirmed in 8.2% and 8.8% of nasopharyngeal specimens from controls and patients, respectively. Moreover, 10.9% and 7.5% of Buffy coats from controls and cases, respectively, were PCR-positive. When performances of both assays for detection of the pathogen were assessed, the sensitivities of MIF and PCR were low and comparable. However, MIF demonstrated higher specificity, positive predictive value, and negative predictive value than PCR.

The bacterium Simkania negevensis is a germ associated with respiratory diseases. This study aims at estimating the prevalence of Simkania in the Jordanian population. Serum samples from 664 Jordanian males and females, aged 2 to 86 years were collected. IgG and IgM Simkania-specific antibodies were detected using an indirect immunofluorescence test. Seropositivity titers for IgG and IgM were defined as 1:8 and 1:10, respectively. The overall prevalence of IgG antibody in all examined Jordanian nationals was 58.4%. IgG seropositivity was low in children under the age of 10 years (34.2%), and increased rapidly with age and ranged between 49.4% and 72%. Simkania-specific IgM was detected in 24.8% of subjects. IgM prevalence in children under 10 years was lowest (10.5%) and increased in older ages and remained above 20%. Overall detection rates of both IgG and IgM were significantly higher in females than males (60.7% vs. 54.5% for IgG and 26.7% vs. 21.7% for IgM). These data indicate that Simkania infection is highly prevalent in Jordan. The high level of seropositivity is most likely maintained by re-infections or chronic infections. Our data may serve as a basis to elucidate the pathogenesis of Simkania in Jordan.

Introduction: The correlation of Chlamydia pneumoniae to coronary artery disease (CAD) in Jordan was investigated in this study. Methodology: Totals of 361 atherosclerotic patients and 392 apparently healthy controls of both sexes were enrolled. C. pneumoniae-specific IgG antibodies were measured by the microimmunofluorescence assay (MIF). The presence of the bacterial DNA in the blood by polymerase chain reaction (PCR) was also tested. Results: The overall IgG seroprevalence, estimated at a titer of 1/16, was insignificantly higher in patients (75.9%) than in controls (71.7%). About 59.3% of patients demonstrated seropositivity at titers ≤ 1/256, which are suggestive of chronic or presumed past infection, whereas 54.1% of controls were seropositive at these titers (p > 0.05). Analysis of gender-specific seroprevalences revealed no obvious relation between C. pneumoniae and atherosclerosis in males (78.9% and 77.9% in atherosclerotic and control males, respectively; p > 0.05). However, a significantly elevated seropositivity was detected in atherosclerotic females (71.7%) compared with control females (64.2%). On the other hand, the PCR-based detection of C. pneumoniae DNA failed to correlate the bacterium to atherosclerosis. Conclusions: We were unable to show a strong association between C. pneumoniae and CAD, potentially because of the presence of high seroprevalence of C. pneumoniae antibodies and the unreliability of the whole blood-based nested PCR technique used.